Pre-flight planning

Planning conducted prior to a flight in a low-stress environment can enable a pilot to produce a safe strategy for the flight (in other words the pilot can be proactive and plan ahead to select a safe route and establish “decision points” during each flight phase). Collaborative decision-making with ATC, weather services, and other pilots will help to size up a general situation. Good pre-flight planning also reduces the workload once airborne.

The Airspace Infringement Working Group has produced this guidance to cover the key aspects of successful pre-flight preparation and planning.

01. Planning your flight

Planning conducted prior to a flight in a low stress environment can enable a pilot to produce a safe strategy for the flight (in other words the pilot can be proactive and plan ahead to select a safe route and establish “decision points” during each flight phase). Collaborative decision-making with ATC, weather services, and other pilots will help to size up a general situation. Good pre-flight planning also reduces the workload once airborne. Part of that planning should be contingency planning to be able to react calmly and efficiently if an en-route diversion becomes necessary due to insufficient fuel to reach your destination with an adequate reserve, deteriorating weather or an un-well passenger.

As GA pilots, the eagerness to return to flying after a prolonged time away is understandable. The opportunity to go flying, enjoying the views below, to travel to other parts of the country, visit friends, practice skills and the challenges associated with flying is not underestimated. Previous articles in this series highlighted the use of Frequency Monitor Codes (FMCs) and UK Flight Information Services as an essential part of planning your flight. Let’s not underestimate time spent on planning the flight can easily reduce your workload once in the air. There is the phrase about poor planning and performance.

Do we still look at a chart before going flying or purely rely on the electronic flight planning software? The chart provides a ‘flat’ view of the intended track whereas the electronic can provide the side view as well. How close will you get to other aerodromes, private strips, gliding sites, restricted or prohibited areas? How high is the land, or that obstacle? The fan markers on the extended runway centreline mean something, don’t they? How do I find out if parachute dropping is taking place tomorrow? Look, that aerodrome looks like it’s now closed. All these questions can be answered with a bit or time preparing before even setting off to the aircraft.

Manchester Low Level Route

Manchester Low Level Route

Manchester Low Level Route

Anticipating frequency changes and expecting what is likely to be seen along the busy route can be part of the planning phase and reduce workload at the time.  Has anything changed since you last flew there?

Planning a flight with a route outside controlled airspace can reduce your workload by eliminating the need to constantly change frequencies, request crossing clearances, selecting squawks and repeating your details as you change between units. The need to navigate accurately and maintain a good look out for other traffic is the core part of any flight but some of this workload can be reduced by thoroughly planning the flight beforehand. The alternative of the ‘extra pair of hands or ears’ provided by ATC can be helpful. As two flights are never the same it can be hard to provide a comparison between a second, identical, flight; one outside controlled airspace with minimal ATC interaction, if any, and one speaking to ATC with the various services available.

Many GA flights take place at aerodromes with an ATZ and many pilots will fly around to avoid without obtaining permission to enter. However, from a safety aspect, monitoring the frequency or making your presence known can only enhance safety for yourself and other pilots in the area.

Farnborough & Blackbushe

Farnborough & Blackbushe

Farnborough & Blackbushe

As part of planning how many pilots have refreshed their understanding of the procedures since the airspace was introduced in February 2020?

Electronic flight planning and GPS has no doubt made life easier with multiple time saving and safety related benefits, but has it meant some skills and knowledge have been lost? Fuel planning, estimates, the weight and balance are just some. The electronic radio log is a great benefit listing the correct frequencies and FMCs for the planned route. The listing of the callsigns, whether the unit is LARS, Information, or whether the airspace is a CTR, CTA, MATZ, ATZ, or AIAA is all helpful and will allow more time to concentrate on the core skills of navigating and looking-out rather than trying to work it all out as the flight continues.

Obtaining the latest meteorological information is essential and obviously the closer to the time of the flight the better. Individual preferences, recommendations from friends and other pilots how to obtain the latest and best information may vary. It is a personal choice, but it is essential. Unfortunately, every year there are reports of pilots experiencing difficulties because of weather and requiring assistance. Did they plan correctly or understand the information available?

Obtaining the latest NOTAM information is essential and if you don’t understand the content of the text or coding then why not get help from your club or another pilot? The text follows a standard international format which needs to be read and understood by pilots worldwide, which is why it sometimes appears complicated. Don’t forget a great deal has changed in the last year, with units closed or with revised operating hours, airspace declassified at certain times along with guidance on how to operate in the airspace when it is declassified and facilities that may no longer be available including fuel.

Coventry and Wellesbourne Mountford

Coventry and Wellesbourne Mountford

Coventry and Wellesbourne Mountford

Two examples with an ATZ under a CTA.  Is there any advice or information to help avoid infringing the Birmingham CTA that is available when planning the flight?

There are probably very few smaller aerodromes who do not have a website or have their relevant information published electronically. If not, there’s always the various GA guides. The aerodromes requiring PPR, and possibly a telephone briefing prior to landing, are operating with safety in mind. It’s not only for your safety but also for the other pilots who will be operating to ensure everyone is following the same procedures. Safety is paramount and why would you try to jeopardise your own by failing to brief and plan your flight correctly?

White Waltham and Denham

White Waltham and Denham
Two examples of an ATZ inside a CTR, where planning and understanding the procedures is essential.

White Waltham and Denham

Two examples of an ATZ inside a CTR, where planning and understanding the procedures is essential.

The past year has meant many units have revised their operational hours due reduced traffic levels and reduced the available services with staffing restrictions in control rooms. This was especially noticeable during the ‘lockdowns’ when GA activity was minimal. Therefore, the available services may be restricted for some months as operational control rooms continue to maintain social distancing restrictions and stringent hygiene protocol with less staff available. A NOTAM check should make us aware those units affected and ensure none of us are surprised when enjoying the blue skies again this summer.

02. Are you fit to fly?

Ask yourself the question ‘Can I really say, I’m Safe?’

I             ILLNESS            Are you well enough to fly?

M          MEDICATION Side effects, covering problems?

S            STRESS               Any pressure, passengers, annoyed?

A           ALCOHOL          Less than 25% of UK driving limit!

F            FATIGUE           Enough sleep, well rested?

E            EATING              Blood sugar correct?

Some Hazardous Pilot attitudes

Hazardous Attitude Antidote
Anti-authority – “Don’t tell me”/ ”The regulations are for someone else” “Follow the rules, they are that way for a reason”
Impulsivity – “I must act now, there’s no time” “Not so fast, think first”
Invulnerability – “It won’t happen to me” “It could happen to me”
Macho – “I can do it!” “Taking chances is foolish”
Resignation – “What’s the use?” “Never give up. There is always something I can do”

How can an ordinary pilot expect to survive, is it just the luck of the draw?

Here is some food for thought.

  • There is a difference between skill and judgement, judgement is more important to survival than skill.
  • The less skilled self-disciplined pilot is often at less risk than an experienced pilot pushing to the limit.
  • If you are not aware of your personal limits, your first mistake is likely to be your last.

Are You Ready to Fly?

  • Is your licence, medical and logbook up to date and valid?
  • Is your insurance up to date and valid?
  • Are machine’s papers valid, certificates, engineering sign offs etc
  • Are your maps, charts and flight guides up to date and valid?
  • Did you check and interpret for both planned flight and for possible diversions; have you followed the guidance in the next sections in this section?
  • Assessed the likelihood of carburettor icing?
  • What runway length do I need for this configuration?
Your machine
  • Are the necessary documents on board?
  • Have you completed necessary weight and balance calculations and planned aircraft loading appropriately?
  • Have you created a distraction free climate for pre flight inspection?
  • Are you following the POH guidance on pre flight inspection?
  • Is my safety gear checked for validity, stowed correctly and accessible once the aircraft is loaded?
  • Have I briefed the passenger thoroughly on emergency drills, sterile cockpit procedures and how they can contribute looking out for other aircraft?
As I close up
  • Have I done as much thinking and planning on the ground so that if I meet trouble in the air I will have sufficient capacity to AVIATE, NAVIGATE and COMMUNICATE.
  • Do I have the right recent experience and skill level to execute this flight safely?

Download this checklist from GASCo: GASCO Checklist

03. Planning a weather briefing

No flight should depart unless the pilot has briefed the weather.  This is not only a legal requirement, but it is abundant good sense.  There are frequent reports of fatalities, injuries, incidents and airspace infringements resulting from pilots not briefing the weather properly.  This requirement and advice holds just as much for a local flight as it does for an international flight.  For example, there are often reports of flights in a series of short local introductory flights being compromised by changing weather that the pilot had not briefed.

For safe operation, the principal met information that the VFR pilot needs is cloudbase, visibility, wind and precipitation.  The IFR pilot additionally needs to know about freezing level, icing conditions and turbulence.

This information is available from three types of source:

  • Weather models;
  • Reports of actual conditions; and
  • Meteorologists’ interpretation of those conditions and models.

All three play their part in a thorough briefing, but because of the ease of access and quality of presentation on the internet, this need not take much time or effort, and this brief will show that a weather briefing can be both quick and full.


Whatever means you use to get the information; all weather observations are made at a specific time and forecasts for a specific time or time period; timestamps are part of the information. Make sure you are looking at the most current information, covering the period you require.  Many pilots have experienced a problem in flight because they were looking at the previous day’s briefing.

Weather models

Weather models have only been available to non-experts for a relatively short time, through the power of the internet, they now offer a wealth of quickly assimilated information to the pilot.

There are many ways to access the models but this brief will focus on the freely available website and app

It can be configured to the needs of the pilot – with tabs for Wind, Rain, Thunderstorms, Cloudbase, Visibility, Fog, Freezing Altitude and much more.

It gives access to five different models (the computers doing the data correlation)

and can give the current weather and a forecast for a date and time several days ahead, or an animation over a period.

Some words of caution on models and timescales

Some of the specialist aviation parameters, such as cloudbase and visibility, are only offered by one model (mainly ECMWF – European Centre for Medium-Range Weather Forecasts).  And, most importantly, longer term modelling gets increasingly less accurate and less reliable and there is little point looking ahead more than three days;  the closer to the time of the flight the more reliable it is.

With those caveats in mind, Windy can offer a remarkable oversight and insight into current and forecast weather.  Notice the flag showing local conditions, in this case at Wolverhampton Aerodrome (Halfpenny Green):

And this can be zoomed in to as large a scale as you wish.  These examples are around Sherburn-in-Elmet Aerodrome, showing the reasonably good immediately local weather but also the poor conditions to the southeast and the risk of fog all around.

All of those parameters can be clicked through and easily interpreted in seconds.  When you start, it might make sense to use the ECMWF model, but as you gain experience, it is a good idea to have a look at the various other models because they do differ, the more so the further ahead you look, and to take the most pessimistic view.

Another great interpretation of the models is to look at a cross-sectional GRAMET view provided free by autorouter on  The example below shows the forecast for a flight from Norwich to Liverpool at 5,000 feet.

This is probably a little more use to the IFR pilot than the VFR, as cloudbase is not its forte, but it is particularly good at forecasting icing levels and the likelihood of thunderstorms.  Again, it offers two models, GFS and DWD, and it is a good idea to assume whichever is the more pessimistic.

Also, the UK Met Office site (see below and at ) includes useful model data which can be found on the maps, accessed from the bottom section of most pages. An advantage is that some pages show historical reality, for example how a front has moved on the rainfall pages. This helps to visualise when conditions will improve or deteriorate.

Meteorologists’ interpretation

Both the horizontal Windy and the vertical GRAMET views are automated presentations of computer data and rely on the pilot to understand and interpret them.  The view is of the raw output from the model and lacks the interpretive wisdom of a forecaster.

It is a good idea additionally to get a meteorologist’s interpretation, as they apply their knowledge, training and experience.

The two main ways a UK pilot can access an aviation meteorologist’s interpretation are the Met Office’s forms (215 and 214) and Terminal Aerodrome Forecasts (TAFs).

Form 215 ( has a detailed forecast of visibility, weather, clouds and 0°C isotherm for the whole country.  It is important to note the time that the zones are valid and then look at their speed and direction of movement to have a forecast for the time of your flight.  Unlike Windy, the forecast is over a wide area and relatively fixed in time, but it does have the benefit of having a trained eye cast over it.  Again, you should look at the most pessimistic part of the forecast.

The forms below are for the same time period as the screenshots of Windy above, and paint a picture with more meteorological detail, but over a more extended period and in larger, more broad-brush, areas.

The spot wind form (214) is included for completeness, but in fact the wind away from the surface is the most predictable aspect of meteorology, and the wind report and forecast is just as accurate and much more usable than Form 214.

The other human interpreted forecast available to the GA pilot is the TAF.  This is only for one spot (the airport for which it is reported) so needs to be used with increasing care the further you are from that airport, both horizontally and vertically.  Thus, Heathrow’s TAF is a very reasonable forecast for conditions at Fairoaks, as they are close and at the same elevation, but the Leeds Bradford TAF may have little to offer about conditions at Sherburn, because of significant geographical differences between the two, particularly elevation.

A TAF is, of course, a forecast, and reality can be both better or worse than forecast. TAFs are sometimes amended during their period of validity, but deterioration must be significant to trigger an amendment. So be prepared for possibly lower cloudbase, poorer visibility and so on.

Some of the uncertainties in TAFs are dealt with by PROB30, PROB40 and TEMPO

PROB30 describes weather that there is a reasonable probability that you will encounter, and must be prepared for.  PROB40 should be interpreted as a strong likelihood, and is the weather you should expect.

TEMPO means that there is a strong likelihood that the conditions described will be encountered at some time between the times specified, for periods of between 30 and 60 minutes.  Thus TEMPO 1216 SHRA means that any time between 12:00 and 16:00 UTC you can expect short lived rain showers.

And remember that the TAF says very little about en-route conditions.

Actual reported weather

The final element is the Meteorological Aerodrome Report (METAR or “Actual”).  This is a very accurate snapshot of conditions at the time the measurement was taken, and you should avoid departing for an airfield without knowing the METAR, but also remember that it is only a snapshot, and things can change markedly in the time it takes to fly there.

TAFs and METARs are available on a wide range of sources, for example SkyDemon, and are often (for example on SkyDemon) presented in plain language.

Some METARs are accessible in flight using VOLMET and a much wider range are available on a number of airborne products such as Golze, Garmin Connext and some ADS-B receivers.

If your destination does not issue METARs, consider phoning to ask about current weather. The answer may well be provided by someone who is not trained, so should be treated with caution; however,  a comment like “we are flying, but only circuits” is useful.

London and Scottish Information Services can be asked to call the destination to ask for a weather report.  It is also useful to call ahead on the destination aerodrome’s frequency to get an actual, as it can give extra minutes to plan and execute a diversion.

When and how to brief

One approach to how and when you look at the different sources of information would be:

  1. Over the couple of days before a flight, build up a mental picture of the expected conditions by looking at Windy, moving the timing slider to see how the conditions are moving and switching between models to get a feel for the uncertainty.
  2. On the morning of the flight, look at Forms 215 and 214 to get a meteorologists’ overview of the situation.
  3. Look again at Windy, getting a more precise idea of the local conditions.
  4. Get the TAFs for airports along and around your route to check that they tie up with your mental picture, checking for any unexpected differences.
  5. Immediately before departure look at the METARs for destination, alternate and enroute airfields for a snapshot of conditions.

Remember that TAFs and METARs give surface wind.  For a rough idea of the 2000 feet wind add 30° and double the strength.

Although this seems laborious, with a lot of steps, with experience it can be done surprisingly quickly.


The weather is often quite unpredictable.  A tiny variation in surface cooling can turn infinite visibility into fog in minutes and a factory chimney can be the difference between fluffy clouds and a thunderstorm.

It is easy to confuse precision and slickness of presentation with certainty.  Just because a weather model shows graceful lines, many colours and precise parameters does not mean that you will see those very conditions.

Always take the most pessimistic view and plan for the worst, with a backup plan for even worse weather.  This is particularly true if you are not qualified and current to fly in IMC.

The future

Even as we write this document, new presentations and interpretations are becoming available.  SkyDemon is shortly (possibly before this paper is published) introducing a “Flyable Conditions” layer, which allows the user to set ceiling and visibility preferences, and then shows on the map where flying conditions exceed, meet or are below those minima:

And several suppliers are experimenting with 3D views, which allow you to fly your route virtually and see the conditions you might expect.  So it pays to stay up to date with what’s possible.


It is your responsibility to have the best possible information about the weather on departure, enroute, at destination and at your alternates.  There are many sources of this information and we have mentioned only a few.  You should use what you are comfortable with, but the important thing is that you do get the information.  These days it is the work of a moment and it is a life (as well as embarrassment) saver.

04. Weather: Threat and Error Management

The term Threat and Error Management (TEM) is a concept that we practice in everyday life; more will be explained in later sections. The principles of TEM are to encourage pilots to have situational awareness of the risks that might put them in danger and to consider plans to mitigate those risks.

Identifying weather related risks is an important factor, so an understanding of how to manage risks such as unexpected weather changes is a fundamental part of good airmanship. Possible areas of specific risk areas are:

  • Low Visibility (including Fog).
  • Cloud (Low cloud base, Convective clouds etc).
  • Showers and Thunderstorms.
  • Wind and turbulence.
  • Making the decision – pre-flight risk assessment (en-route, at destination and alternatives).
  • Operating to/from/between ‘green-field’ sites.

To be able to apply effective weather related TEM, it is important to understand the difference between Civil Aviation Authority (CAA) regulated aviation meteorological products and information, and other, unregulated, sources of meteorological information.

Narrative 3 (03. Planning a weather briefing) introduced the fact that no flight should depart unless the pilot has briefed the weather using, as a minimum, regulated products, whilst also offering guidance on how to obtain met information from other sources. The CAA is the Met Authority for the UK and designates the Met Office as the UK Air Navigation Service Provider for the provision of meteorological forecasting and climatological services for civil aviation. The UK Met Authority’s objective is to supply operators, flight crew members, ATS units, airport management and other civil aviation users with the meteorological information necessary for the performance of their respective functions, thus contributing towards the safety, regularity and efficiency of air navigation. The UK Aeronautical Information Publication at GEN 3.5 describes the UK system and services available.

As with all products providing aviation related information, it is vital that a user understands not only how to use them but also understands the accuracy and validity of the information,  and ,when using unregulated products, whether or not the data used is derived from the regulated source. When using weather apps – aviation and non-aviation – you’ll need to recognise the limitations and possible risks of using any of these. Some considerations include:

  • Is the information provided complete?
  • Is information managed effectively within the app – is only valid information displayed, and is expired information removed promptly?
  • What level of data validation and verification does the provider employ?
  • Does the provider identify and manage any errors effectively? (e.g. notification to users, correction of errors and facility for reporting issues).
  • What measures are taken to ensure that information taken from the Met Office is not lost, altered or misrepresented?

When utilising VFR moving maps it may be useful to recall that navigation information isn’t usually coupled with weather information, and if it is, databases may not include full information. Depending on the route selected, GPS navigation could lead you to fly into adverse weather such as haze, fog, heavy rain, snow or thunderstorms. To avoid this risk carefully prepare your flight on the ground including weather recognition, and if applicable, refresh weather information during the flight.

The following section is not to ‘re-teach’ the basics about regulated products but to provide further, practical guidance to users on how to interpret and ‘read’ the forecasts and to help them to be able to use the information they contain more effectively. The intent is to reduce the number of incidents where weather has been a significant contributory factor and the information in this section is provided in order to support this objective by helping pilots to enhance their knowledge and also by helping instructors and examiners to more effectively assess the level of pilot skills in the use of weather products and weather-related decision-making.

For example:

  • TAFs/METARs give the cloud based on the ground level at the reporting aerodrome.
  • Values in TAFs do not represent a single forecast value but rather a range of potential values (A table describing the range of wind, cloud and visibilities that TAFs cover can be found on the Met Office website in the Pilot Resources section).

By way of a reminder, whilst planning and operating, the guidance for the suitability of the weather en-route can be found in the following regulated aviation weather briefing products:

  • TAFs/METARs.
  • Aerodrome Warnings.
  • F214/215.

All regulated products are available free of charge via the Met Office Aviation Briefing Service. The Aviation Briefing Service also includes additional UK and European information such as synoptic charts, weather map viewer, observed and forecast map layers (satellite imagery, lightning and thunderstorm layers), rainfall radar and Aerodrome Warning email alert service.

Having briefed against regulated products pilots can, if necessary, contact Met Office meteorologists for further forecast clarification.

It is recommended that as pilots we enhance our confidence in weather decision-making, for example watching forecasts on TV, keeping an eye on METARs and TAFs even when not flying, studying radar and satellite imagery, talking to fellow pilots, sharing weather experiences and reading books and articles and attending aviation meteorological courses. It is also essential to review the weather-related decision-making aspects of your pre-flight risk assessment routine and to carry out post-flight analysis.

The Met Office provides a range of Pilot Resources to support the use of regulated aviation meteorological products and the GetMet publication provides further information on regulated products and how to obtain them. The UK experiences very changeable and often unseasonal weather conditions so it is vital to focus on flight safety in IMC conditions – i.e. making decisions when assessing whether, or where, to fly when IMC conditions exist or are forecast – for example, taking more time to consider potential contingency plans and diverts to support effective decision-making en-route. It is good practice to train/remain current on using basic flight instruments in case of inadvertent entry into adverse weather conditions – an event which could result in loss of control due to spatial disorientation.

In applying TEM follow the concept of ANTICIPATION – RECOGNITION – RECOVERY:

ANTICIPATION: Consider your limits and how the forecast cloud and visibility may present a threat; even if the weather seems fine, what could go wrong to spoil your day.

RECOGNITION: A safe flight depends on being able to conduct safe VFR navigation and respond to unexpected hazards conditions or the weather being as forecast or improving as forecast and not deteriorating faster than expected.

RECOVERY: At each decision point you MUST have planned actions for the eventuality that the weather has not improved or is deteriorating further on your route.

Weather-related scenarios

These case studies (based on real events) include:

  • Overview – describe a proposed flight from A to B.
  • Provides ‘example’ TAFs/METARs and charts for the proposed flight.
  • Considers TEM in the planning and operational stage.

They relate to flying conditions that may be experienced with different air masses in the UK at different times of the year. They include risks they may pose, plus some suggested best practice mitigants and decisions that could be made.

They are also included on the Met Office website – Pilot resources – Introduction to Threat and Error Management (TEM), linked here to download:

  1. Case 1: High pressure – Summer flight with atmospheric convection
  2. Case 2: Tropical Maritime
  3. Case 3: Spring and Autumn

Case 1: High pressure – Summer flight with atmospheric convection

Route: Southampton to Norwich (VFR) / Date: 27 August 2017, departing 0800 hours UTC

Synoptic situation

What are the broad features in the synoptic chart, what is the main type of airmass covering the region and what kind of weather can we expect from it? How strong is the wind likely to be and what will its direction be?

Synoptic Chart 27 Aug 2017

Figure 12-1 Synoptic Chart 27 Aug 2017

The south of the UK is dominated by an anticyclone (1019 hPa), giving predominantly fair weather and gentle winds. There are not many isobars on the chart so we can assume that the winds will be light and variable although mainly north-easterly on the planned route and, when considering the time of year, it is possible for sea breezes to develop around the coasts. Looking at the wider flow, the airmass seems to have a mixture of maritime and continental influences; the air is likely to be warm and predominantly dry, generating just fair-weather clouds but with some lower cloud bases in moister air to the west. The presence of an upper cold front to the east of England complicates the picture somewhat and will need investigating. What is the cloud base associated with it? Does it produce rain and if so, how much of it is reaching the ground?  How much does it affect the visibility?

Anticyclones (high pressure) are normally associated with clear skies and good weather, so it is often assumed that there are no aviation hazards to be considered.  However, the clear skies can allow overnight temperatures to fall and early / late radiation mist and fog can occur.  Furthermore, the generally subsiding air beneath an anticyclone can trap pollution, smoke, dust and other microscopic solids to make the atmosphere particularly hazy. This can adversely affect visibility, particularly from the air to the ground (slant visibility).  Finally, under clear skies the ground can heat quickly during the day and this can trigger convective processes leading to turbulence, gusty winds, sea breezes, spreading cloud, showers or even thunderstorms.  Sinking air under high pressure does tend to suppress convection, but not always and usually not in the first few thousand feet – don’t get caught out!

So, what kind of hazards may be associated with convection?

Atmospheric Convection

Figure 12-2 Atmospheric Convection

Figure 12-2 Atmospheric Convection

Area forecast

Looking at the F215 chart, is there anything along the route that I should be taking into consideration? What are the main cloud base and visibility?  What is the altitude of the freezing level? Can I expect any fronts, weather, turbulence or icing?

 F215 27 0800 to 27 1700 Aug 2017

Figure 12-3 F215 27 0800 to 27 1700 Aug 2017

For the flight from Southampton to Norwich I need to focus on areas B & C. Visibility is, generally, excellent but I may encounter patches of mist until 09Z.  Hill fog may even be possible on windward slopes, with cloud as low as 500 feet.

There are extensive areas of cumulus and stratocumulus with a cloud base of around 1500-2000 feet. Considering the highest point of the Cotswolds is ~1100 feet, that doesn’t leave much of a gap.  Additionally, areas of stratus are possible early in the planned flight period and near windward coasts.  The freezing level is, thankfully, high at this time of year and should not be an issue and this is confirmed on the chart.  The upper front on the synoptic chart appears to be no more than residual cloud, hence not precipitating nor reducing the visibility and with no significant turbulence.

Site specific information

Let’s have a look at the METARs/TAFs along the route, do they confirm the information contained in the F215? Have you checked possible diversion airfield(s) along your track as well as your destination? Are they suitable?

  • METAR EGHI 270650Z 01005KT 330V040 CAVOK 15/12 Q1018=
  • METAR EGLF 270650Z 31001KT CAVOK 15/14 Q1018=
  • METAR EGUB 270650Z 34002KT CAVOK 15/13 Q1018 BLU=
  • METAR COR EGLL 270650Z AUTO 04005KT 9999 NCD 17/11 Q1018 NOSIG=
  • METAR EGGW 270650Z AUTO 02006KT 350V060 9999 NCD 14/11 Q1019=
  • METAR EGSS 270650Z AUTO 36005KT 330V040 9999 NCD 15/11 Q1019=
  • METAR EGSC 270650Z VRB01KT CAVOK 14/11 Q1019=
  • METAR EGYM 270650Z AUTO 33003KT 9999 NCD 13/12 Q1018=
  • METAR COR EGSH 270650Z 29004KT 250V320 CAVOK 15/12 Q1018 NOSIG=
  • TAF EGHI 270625Z 2706/2715 VRB03KT 9999 FEW045=
  • TAF EGSC 270659Z 2706/2715 35003KT CAVOK=
  • TAF AMD EGSH 270557Z 2706/2715 VRB03KT 9999 FEW045=

The METARs are looking promising, most airfields reporting CAVOK (Cloud and Visibility OK), implying that the visibility is 10 KM or more, or NCD (No Cloud Detected). Some airfields are not yet opened but the few TAFs available indicate good conditions too. Based on these, it looks like the early visibility problems that are highlighted on the F215 have now cleared.

Threat & Error Management

ANTICIPATION: The weather seems fine – but what could go wrong to spoil your day?

  • Visibility is already good at Southampton, but what about the surroundings in the event of an emergency in the early phases of flight?
  • Can you fly your planned route in appropriate airspace when constrained by the terrain and forecast cloud? EGHI to EGSH involves some busy airspace with limited scope for manoeuvre.
  • The surface visibility may be over 10 KM, but how far and how clearly can you see the ground in the cruise? Will it be far / clear enough to allow accurate navigation in busy airspace?
  • How will variable wind (albeit light) affect your navigation?
  • What is your plan for convection? Whilst it’s not specifically forecast for your area it can occur in these conditions in the first few thousand feet without generating cloud or weather (what glider pilots call “blue thermals”).  Vertical motion and turbulence from convection may make it more difficult to maintain a constant height/altitude.
  • If convective cloud, showers or even thunderstorms do develop unexpectedly what is your avoidance plan? (there are thunderstorms forecast across the English Channel in area D.
  • Some METARS are showing 15 – 17°C at 0700 hours UTC. What is the maximum temperature for the day and how will it affect your aircraft’s performance?

RECOGNITION: A safe flight depends on being able to conduct safe VFR navigation and respond to unexpected hazards.

  • Could you consider delaying departure for an hour or two to ensure clearance of mist / fog patches?
  • With possibly limited air-to-ground visibility, do you intend making more regular navigation (gross error) checks and plan more regular waypoint checks?
  • What is the variable wind doing to your track in relation to navigation & airspace limitations?
  • Are you maintaining height/altitude accurately? Are you aware of vertical airspace limitations?
  • If you need to avoid convective cloud or even showers, what are your plans for diversion, delay, extended fuel use etc?

RECOVERY: The potential combination of relatively poor visibility from the air and the development of apparently random convection / turbulence makes planning particularly difficult.

  • Do you have diversion information for appropriate airfields along your planned track?
  • Have diversion plans and clear go / no-go decision points for the flight. Be prepared to develop and adapt recovery plans as situations develop.
  • What is your plan for becoming unsure of your position? When did you last practise with London Centre / D&D on VHF 121.5MHz?
  • Ensure careful monitoring of fuel, distance, speed and elapsed time when dealing with delays (e.g. showers).
  • During take-off and landing, be ready to deal with convective gusts and reduced performance due to high temperatures. Be ready to go around!

Anticyclonic conditions should mean a pleasant and straightforward flying day.  Conditions for this flight are forecast to improve after a misty or foggy start and METARS suggest that this is already true.  It’s looking good!

However, be aware that while winds may be light, they can also be variable, so monitor the impact on navigation and airspace avoidance.  High pressure can trap haze in the lower atmosphere, affecting air-to-ground visibility.  Higher ground temperatures can introduce hazards that are not explicitly forecast such as convection / thermals, associated turbulence, gusty ground winds and high-density altitude values.  Don’t let fine weather cause complacency.

Finally – warm summer air can be surprisingly humid: beware carburettor icing.

Case 2: Tropical Maritime

Route: Cambridge to Gloucester (VFR) / Date: 11 March 2017, departing 0800 hours UTC

Synoptic situation

Describe the broad features in the synoptic chart, what is the main type of airmass covering the region and what kind of weather can we expect from it? How strong is the wind likely to be and what will its direction be?

Synoptic Chart 11 Mar 2017

Figure 12-4 Synoptic Chart 11 Mar 2017

Most of the UK is covered by a south to south-westerly Tropical Maritime airstream. This airmass is mild and moist in its lowest layers, particularly over coastal areas and hills where it brings low clouds, drizzle and local hill fog.  Judging from the number of isobars the gradient wind does not seem to be an issue but the complexity of the frontal system over the Atlantic indicates that conditions will deteriorate quickly and for quite a long time.  The window of opportunity is brief and closing in!

So, what kind of hazards are usually associated with this airmass?

Tropical Maritime (TM) Airmass

Tropical Maritime (TM) Airmass

Figure 12-5 Tropical Maritime (TM) Airmass

Area Forecast

Looking at the F215 chart, is there anything along the route that I should be taking into consideration? What are the main cloud base and visibility? What is the altitude of the freezing level? Can I expect any fronts, weather, turbulence or icing?

F215 11 0800 to 11 1700 Mar 2017

Figure 12.6 F215 11 0800 to 11 1700 Mar 2017

For the flight from Cambridge to Gloucester I need to focus on areas C & D where visibility may be reduced in haze, fog or hill fog and where the cloud base may be as low as 400 feet at times. The conditions are expected to improve but will deteriorate further to the west later: not a great forecast for VFR flight. The freezing level is above 8000 feet (AMSL) so there is no risk of icing at low level. Turbulence is expected along the route, but it is only slight. The possible restricted visibility means that you need to check the latest conditions at Gloucester (and the surrounding area) and make sure it will not be below minima for your arrival. In these conditions, it is simply not a good idea to “see how it looks when we get there”!

Site specific information

Let’s have a look at the METARs & TAFs along the route, do they confirm the information contained in the F215? Have you checked possible diversion airfield(s) along your track as well as your destination? Are they suitable?

  • METAR EGSC 110650Z NIL=
  • METAR EGGW 110650Z AUTO 16004KT 2900 BR OVC003 09/09 Q1018=
  • METAR EGTK 110650Z 16005KT 2500 BR OVC005 10/10 Q1018=
  • METAR EGVN 110650Z 17003KT 2000 BR OVC004 10/10 Q1018 YLO2 TEMPO 0600 FG BKN001 RED=
  • METAR COR EGBB 110650Z 16006KT 4800 BR BKN007 10/10 Q1017=
  • METAR EGBJ 110650Z NIL=
  • TAF AMD EGBB 110712Z 1107/1206 17005KT 3000 BR BKN004
  • BECMG 1107/1110 9999 NSW SCT010
  • TEMPO 1110/1114 8000 BKN009
  • PROB40 TEMPO 1201/1206 7000 RA BKN004=
  • TAF EGVN 110741Z 1109/1209 17005KT 2500 BR BKN004
  • BECMG 1109/1112 9999 NSW SCT018
  • BECMG 1113/1115 FEW020
  • BECMG 1200/1203 BKN012
  • TEMPO 1201/1206 3000 RADZ SCT005=

The METARs are actually not very encouraging and indicate that the stratus is quite extensive. The TREND at Brize Norton also suggest a risk of fog during the next two hours. Cambridge and Gloucester airfields are not opened yet but there is no reason to believe that conditions will be any different there. Conditions described by the METARS confirm the information contained in the F215 chart but the TAFs indicate a potential improvement during the morning, with greater visibility and a higher cloud base.

Threat & Error Management

ANTICIPATION:  Consider your limits and how the forecast cloud and visibility may present a threat:

  • Is your departure and arrival time realistic given the forecast conditions at Cambridge and Gloucester?
  • Can you fly your planned route in appropriate airspace when constrained by the terrain and forecast cloud?
  • What is your safety altitude for the flight? Can you achieve this and remain VFR given the forecast?

RECOGNITION:  A safe flight depends on conditions improving as forecast and not deteriorating faster than expected.

  • As well as keeping a good lookout, what is your plan to get en-route METARS or other weather updates?
  • How does this fit in with your wider communications plan?
  • Where and when are your decision points on the route if conditions are doubtful?

RECOVERY:  At each decision point you MUST have planned actions for the eventuality that the weather has not improved or is deteriorating further on your route.  Given the forecast, it is likely that the best weather will always be behind you and away from exposed southern areas.

  • Do you have diversion information for appropriate airfields to the north and east?
  • Have you planned alternative routes to these diversions from each decision point?

The main concerns in this Tropical Maritime situation are low-level cloud and visibility along the route and possible deteriorating conditions on the approaching cold front. Conditions are forecast to improve after a misty or foggy start.  The Brize Norton TAF is encouraging, but also note Birmingham’s best cloud conditions of scattered at 1000 feet.  This is expected to increase and lower to become broken at 900 feet at times.  This is probably due to the fact that Brize Norton is slightly protected in the Thames Valley while Birmingham (and, importantly, Gloucester) are more exposed to the Bristol Channel and Severn Valley.  The movement of the cold front in the west will be key to conditions at Gloucester and this should be monitored carefully.

The flight should only be started once you are confident that en-route conditions are safe, and you should make regular checks on conditions at the destination before continuing past planned decision points.  You must always have an alternate plan for deteriorating conditions AND PUT IT INTO ACTION AT THE FIRST SIGN OF DETERIORATION.

Case 3: Spring and Autumn

Route: East Midlands to Cambridge (VFR) / Date: 15th March 2017, departing 0800 hours UTC

Synoptic situation

Describe the broad features in the synoptic chart, what is the main type of airmass covering the region and what kind of weather can we expect from it? How strong is the wind likely to be and what will its direction be?

Synoptic Chart 15 Mar 2017

Figure 12-7 Synoptic Chart 15 Mar 2017

An anticyclone (1035hPa) extends a ridge over the south of the UK, suggesting settled conditions. A decaying cold front is slow-moving across southern England (the crosses on the front indicate that it is weakening). Despite becoming less active this front retains some of its characteristics.  It is likely that significant amounts of cloud will be trapped under the ridge and this could be thick enough to generate rain and drizzle thus a risk of poor visibility in places.

The time of year is a key consideration for this forecast; it’s almost the March equinox so the length of day and night are nearly equal.  The nights can still be cold and under such high pressure, it would not take long for fog to form in places.  Additionally, away from the front and under any clear sky, the temperature can rise significantly and improve conditions during daytime.

So, what kind of hazards are usually associated with spring or autumn weather? Let’s have a look at the cheat sheet below.

Flying in Spring & Autumn

Flying in Spring & Autumn

Figure 12-8 Flying in Spring & Autumn

Area Forecast

Looking at the F215 chart, is there anything along the route that I should be taking into consideration? What are the main cloud base and visibility? What is the altitude of the freezing level? Can I expect any fronts, weather, turbulence or icing?

F215 15 0800 to 15 1700 Mar 17

Figure 12-9 F215 15 0800 to 15 1700 Mar 17

Focusing on the route from East Midlands to Cambridge and area D specifically, there seems to be a lot of cloud, all at various levels and accompanied by turbulence.  Some moderate icing is expected but the lowest freezing level is expected to be 5000 feet.  The main cloud base is expected to be quite low at around 2000-3000 feet but there will also be significant amounts (BKN) of stratus in some areas at very low level (400-1000 feet), which will persist until midday, so navigation may be challenging.  The visibility does not seem to be badly affected by the anticyclone; there will be patches of fog, but these are expected to be isolated and mainly to the south-east of the UK.  Although the medium level cloud (above 8000 feet) may not affect you directly, it will slow the process of heating the surface to clear mist and fog patches.

Site specific information

Let’s have a look at the METARs/TAFs along the route, do they confirm the information contained in the F215? Have you checked your destination airfield as well as the diversion(s) airfield(s), are they suitable?

  • METAR EGNX 150650Z 22005KT CAVOK 06/05 Q1033=
  • METAR EGBB 150650Z VRB03KT 9999 MIFG VCFG NSC 05/05 Q1033=
  • METAR EGXT 150650Z AUTO 27008KT 4600 BR SCT150/// 06/05 Q1032=
  • METAR EGGW 150650Z AUTO 30003KT 0150 R26/0275 FG VV/// 06/06 Q1033=
  • METAR EGSC 150650Z NIL=
  • METAR EGSS 150650Z 32003KT 2500 R22/0400 BCFG NSC 05/05 Q1033=
  • METAR EGYM 150650Z 23004KT CAVOK 08/07 Q1033 BLU NOSIG=
  • TAF EGNX 150503Z 1506/1606 24006KT 9999 SCT030
  • PROB30 TEMPO 1506/1509 8000
  • BECMG 1602/1605 BKN007
  • TEMPO 1602/1606 2000 BR BKN002=
  • TAF EGGW 150500Z 1506/1606 28007KT 3000 BR FEW020
  • TEMPO 1506/1509 0300 FG BKN001 BECMG 1509/1512 9999 NSW
  • PROB30 TEMPO 1509/1512 BKN008 TEMPO 1520/1606 3000 BR
  • PROB30 TEMPO 1523/1606 0800 FG BKN001 BECMG 1603/1606 22010KT=
  • TAF EGYM 150740Z 1509/1518 24008KT 9999 SCT025=

A few airfields are reporting visibility problems as previously discussed with the synoptic chart analysis but these are not expected to last past 1100 hours UTC.  Cambridge airfield is not yet opened but, looking in the vicinity, both Luton and Stanstead are reporting fog or fog patches.  Marham is CAVOK (Ceiling and Visibility OK) with a NOSIG (No Significant changes) trend.  Of note, Luton (EGGW) is expecting temporary spells of broken cloud at 800ft until midday.  This all agrees with the F215 chart regarding the forecast cloud and the fog patches being mainly in the southeast of the UK.

Threat & Error Management

ANTICIPATION:  Consider your limits and how the forecast cloud and visibility may present a threat:

  1. Is your departure and arrival time realistic given the forecast conditions at East Midlands and Cambridge and the possibility of low cloud along the route?
  2. Can you fly your planned route in appropriate airspace when constrained by the terrain and forecast cloud and visibility? Remember those low cloud patches!
  3. What is your safety altitude for the flight? Can you achieve this and remain VMC, below the freezing level given the forecast?

RECOGNITION:  A safe flight depends on conditions improving as forecast and cloud.

  1. What is your plan to get up to date METARS or other weather information? Online? Phone ahead before departure?  Web cams?
  2. Can you check destination conditions en-route? How does this fit in with your wider communications plan?
  3. Where and when are your decision points on the route if conditions become unsuitable to continue?

RECOVERY:  At each decision point you MUST have planned actions for the eventuality that the weather does not improve or is unsuitable on your route.  Given the forecast, it is likely that the best weather will always be behind you and away from the southeast.

  1. Can you delay departure until you are certain that conditions are suitable along your entire route?
  2. Do you have diversion information for appropriate airfields away from the greatest fog / mist and low cloud risk?
  3. Have you planned alternative routes to these diversions from each decision point?

The main concern in this spring high pressure situation is how quickly the early mist/fog will clear and the variability of low cloud from the weakening cold front. Having analysed the situation, it seems the worst of the conditions are located to the south-east of the UK and may persist until midday.  Cloud base is set to be around 2000 – 3000 feet with visibility greater than 10KM (after 09Z).  However, the anticyclone is likely to trap low level moisture and there is a risk of low-level cloud until midday.  Do you really have to go at 0800 hoursUTC? Consider the duration of your flight, weather improvement times and the length of remaining daylight and good conditions.

The flight should only be started once you are confident that en-route conditions are safe and you should make regular checks on conditions at the destination before continuing past planned decision points.  You must always have an alternate plan for unsuitable conditions AND PUT IT INTO ACTION AT THE FIRST SIGN OF DETERIORATION.

05. Route planning and preparation


Check paperwork before the flight, especially following a long delay, to ensure that the flight is legal. This can include:

  • PPL A: Valid Class Rating (ratings page) and hour requirements
  • LAPL: Hours “Rolling Validity” and hour requirements
  • Medical/PMD Combination valid for type of aircraft being flown
  • Valid Aircraft Insurance that covers the pilot for planned flight
  • Valid CofA ARC or Permit to Fly
  • Part 21 Journey Log: – no defects or defects noted
  • Carriage of documents relevant for aircraft type (LAA Permit to Fly or Part 21)

Planning checklist

Checklists can help avoid overlooking important matters to ensure that all aspects of planning have been covered. This should include:

  • Weather (as discussed in the Met paper at [link])
  • NOTAMs
  • Flight plans, including
    • Moving map and charts up to date
    • Airfield opening times
    • PPR and how to depart from and arrive to your aerodromes in accordance with their published procedures.
    • Terrain
    • Airspace en-route
    • Frequency Monitoring Codes (FMC) and associated frequencies. A separate section explains how to use FMC. The latest Frequency Reference Cards (see Figure 1) are available from the NATS AIS site in printable format and updated at AIRAC Cycle.
    • Planning for alternate aerodromes en-route
  • Fuel – including for possible diversion
  • Weight and balance. CAP2097 issued in February 2021 offers some good advice about weight and balance.

Figure 1

Before flying, ask yourself if you are current and if you are fit to fly. You may wish to use a checklist such as IMSAFE (Illness, Medication, Stress, Alcohol, Fatigue and Emotion).

When planning you may wish to make full use of the following resources:

Use of charts

Make sure your chart is up to date but remember that even the latest chart may not include all changes to airspace along your route. A comprehensive guide to VFR chart resources is found at the NATS AIS website (here) and is available free to all users. Currently the following VFR resources are available:

  • Full list of amendments to all current VFR charts
  • An email notification service detailing the latest amendments to all current VFR charts
  • VFR chart scheduled publication dates
  • VFR chart stockists

Prior to planning a route, check the relevant chart amendment by navigating through the page in Figure 2:

Figure 2

Figure 2

The legend at the bottom of the chart contains the information needed to use the chart effectively.

Use of GPS

  • Learn to use it on the ground. This will help reduce mistakes in the air, avoid loss of situational awareness and prevent your eyes being in the cockpit for too long.
  • Make sure the moving map is configured to show airspace above the planned route as it may be ‘hidden’.
  • Do not simply draw a line between departure and destination aerodromes: mark out legs/waypoints and check along each to make sure there is no controlled airspace (including vertical airspace), danger area, restricted area or ATZ along the path. For each of the airspace structures along the route, either plan to communicate with the airspace operating authority to obtain a clearance and necessary information to enter; or plan to Take 2 around the outside/underneath.
  • If possible, print off a PLOG. This will provide a backup should the GPS fail for any reason. It will also provide en-route frequencies for e.g. aerodromes and LARS units.
  • If weather and NOTAM information is provided on the moving map/software, make sure they apply to the actual day and time of flight rather than the day before when the plan was made.
  • For up to date information on specific NOTAMs, including Restricted Areas (Temporary), Airspace Upgrades and Emergency Restrictions of Flying, call the AIS Information Line on 08085 354802 or +44 (0)1489 887515
  • Be cautious about using the ‘direct to’ function during flight as the resulting track may take you through [designated] airspace. Check the route carefully before following the line.
  • Make sure alerting is switched on and you understand the range of alerts available, for example, the advance warning when approaching controlled airspace. But be aware of ‘alarm fatigue’, particularly if you fly in areas of complex airspace. Many pilots receive many alerts and as a result turn them off without focusing on them ‘because they already know they are near controlled airspace’.
  • Plan on which QNH you are going to use for each leg, preferably the QNH of the airport that operates the controlled airspace.
  • If your airfield uses QFE remember to change to QNH immediately after take-off. Never fly cross-country using QFE and avoid RPS as it increases the risk of infringing.

Threat and Error Management

As you plan the flight use the Threat and Error Management to alert you to issues you may have overlooked.

Plan for maximum safe altitude (the lower limit of vertical controlled airspace less 200 feet if possible) for each leg alongside minimum safe altitude, perhaps alongside the MSA calculation:

Safe altitude
minimum maximum


Plan for distraction. If you are following your plan and become distracted by anything – such as a sick passenger or difficulties on the radio – positively identify that as a distraction and bring your mind back to what you were doing before the distraction occurred:

Think –

  1. What was I doing before the event?
  2. At what point was I interrupted?
  3. How do I get back to where I was?

Distractions often lead to error and can occur at any stage of the flight, and indeed pre-flight if other things are on your mind, from the walk round to securing the aircraft.

06. Planning not to infringe: Threat and Error Management

To many, the term Threat and Error Management, or TEM, suggests a complex activity which is a bit on the heavy side for recreational aviation.

Don’t be put off by terminology. TEM, Risk Assessment and to a degree airmanship have a lot in common. In everyday life we practice TEM and Risk Assessment and use the result to avoid loss or injury; in aviation the same applies.


A threat is an event or error that occurs beyond the influence of the flight crew, increase operational complexity, and which must be managed to maintain the margins of safety. If the threat is left unmanaged, it could lead to an unsafe condition, such as injury or loss, or in aviation what can be described as the aircraft not following the plan or, to use another term, being in an Undesired Aircraft State (UAS). Again terminology, but for example if the aircraft enters controlled airspace by error then it is said to be in an UAS.

Threat management is effectively reviewing your planned flight and looking for where or when factors can threaten the successful outcome. We use TEM in everyday life. You will already be using it in your flying, but as we know from statistics some flights have not well managed the threat, and as a result injury, loss or an UAS has occurred.


Errors result from actions or inactions by the crew.  We all make mistakes some of which have no adverse effect; some, however, have significant effects. Avoiding errors starts with looking for threats and, once identified, putting mitigation measures in place. However, it is also important to recognise and correct errors if they do occur.


An example of how threat management might avoid an error is in the use of a check list. Avoiding the consequences of a wrongly sequenced engine start-up can be assisted by the use of a check list, which if followed cannot result in anything other than the correct sequence. Of course, humans being humans may sometimes decide that they don’t need the checklist and as a result might miss a vital part of the sequence; or they might use the list but still miss part of the sequence in error.

If, for example, in this instance the aircraft was started at full throttle, it might runaway causing damage and injury. What would you do at this point? The obvious thing to do as you sit reading this is to close the throttle and shut down the engine. However, in real life some pilots have only tried to hold the aircraft on the brakes to no avail and crashed into something on the ground; one actually attempted to take-off from the apron only to find that control locks were still in place and a very short fight and crash ensued. Error management in this case would have planned for the potential, engines do odd things at times, and have been ready to close the throttle, shut down the engine and manage the error.

Planning to fly

When it comes to planning a flight an attentive pilot should bring TEM into not just the aircraft preparation, daily inspection, fuel sufficient with a reserve, air in the tyres and themselves, IMSAFE for example, but also threats that could occur during the flight. For example, having decided where you want to go you will of course review the weather for your route and destination. Why? Because although the sky is clear at the home base your destination is 50 miles away and close to the coast and the weather there can be very different. So:

Threat – Potential Weather. Management – Obtain a report and forecast.

Your route takes you close to some quite complex airspace which you intend to remain clear of.  You are using a VFR moving map, with a paper chart marked as a reserve (good TEM if the moving map lost its signal or the battery gave up), which will help keep you clear of airspace as long as everything goes OK! However there is always the risk that even with the best of intentions you may just wander off the magenta line and so you allow a little extra margin by moving your line at least 2 NM from a horizontal boundary were you can.

The Threat – Not absolutely spot on with the planned route could lead to an infringement. Management – Plan a sensible margin.

Having drawn a line, you check for any airspace above or below your route because you plan to avoid it and similarly to the 2 NM buffer you gave the side of airspace you plan a 200 feet buffer when flying below or above.

Threat – Infringing airspace. Management – Identifying limits and planning to avoid.


Studies of several hundred infringements have shown that a significant cause of infringements is distraction. A pilot can be distracted in many ways, but a significant number of distractions have been linked in one way or another with passengers. Delightful though it is to share your flying enjoyment with a passenger, they can also weaken your attention, possibly just when you need all of it to conduct the flight safely. Treat your passenger as a potential hazard and seek mitigation. There are legal requirements for passenger briefings, and it is important that you cover potential passenger threat within the briefing. For example, “During the preparation, taxi, take-off and initial climb please don’t talk to me unless it is an emergency.” So:

 Threat – Distraction by Passenger. Management – Prepare and Brief Passenger.

There are times when a passenger can be of assistance. Mid-air Collision (MAC), is always a threat. You can mitigate by using an electronic conspicuity device, talking to an air traffic service unit and receiving a Traffic Service, and of course lookout. With a passenger in the cockpit there is a second pair of eyes and you can add these to your own lookout, with a short briefing, to assist to manage the threat.

Threat – MAC, Management – Ask passenger to assist with lookout.

Route planning to avoid an infringement

The CAA’s Avoiding airspace infringements  card is designed to prompt thought when planning and executing a flight so that as a pilot you have made a positive plan to avoid an airspace infringement. That may sound pretty obvious, but the key to avoiding an infringement is to positively plan not to have and infringement. This means looking at your route and seeing where there is potential for an infringement, the threat, and planning how you will avoid the infringement, the management.

Let’s look at a practical example of planning not to infringe. You plan to fly from City Airport, Manchester (Barton) near Manchester, to Sywell, near Northampton. First get your chart out, make sure it is up to date, (that’s another threat that you have avoided) and look at the route and see where an infringement is more likely to happen unless you plan to avoid it.

There are several such areas. The Manchester Low level Route (LLR) is the first. The most obvious avoid is flying too high when travelling within the LLR. The less obvious, and from the actual infringement reports the most likely to happen, is not descending from a higher cruise level early enough and flying through the base of the airspace above the entrance of the LLR. The other error, although not as common, is starting to climb too early and flying through the base of the airspace on the way out. So, the plan should include a fixed waypoint before the entry by which the level that you fly through the LLR must be established, and a point at the other end where you know that you are clear and safe to climb. Don’t forget that the base of the airspace over the LLR is based on the Manchester QNH, so you must have the altimeter set correctly before you reach the entry waypoint.

Figure 1

Having left the LLR you will want to climb from the abnormally low level. The threat here is that the Manchester CTA immediately south of the LLR has a base of just 2,500 feet and it won’t take long for most aircraft to reach that level. Make sure that you have a plan that will keep you below the CTA with a margin for error. Remember the ‘Take 2’ initiative? Where possible stay 2NM horizontally from the edge of controlled airspace and 200 feet below the base when underneath. So, in this case set an initial climb limit of 2,300 feet. And the easiest way to remember it is to write it down clearly on your log.

Threat – Overshooting your planned height. Management – writing it down on your PLOG.

Having flown past Crewe, the bases of controlled airspace for the rest of the way to Sywell don’t go below 4,500 feet so, given usual cruising levels, vertical infringement shouldn’t be an issue? But do make sure that you have noted an upper limit for your flights, say 4,300 feet on your PLOG just in case you get tempted to fly higher at some point. It’s easy to miss some of the annotations on the chart in-flight, particularly if it’s a bit bumpy and there are other things to do.

Threat – climbing into airspace, Management – writing an upper limit on your PLOG.

Figure 2

It is possible to infringe an Aerodrome Traffic Zone (ATZ). You will note that along the way your route passes close to the Tatenhill ATZ. This is a threat to manage. The upper limit is at 2,450 feet above mean sea level. You could fly over it, or around it. Have a plan before you take-off, and just in case note the frequency of Tatenhill so that if you need to call you can and avoid an infringement or alternatively just to maintain a listening watch for spatial awareness. Remember to be ultra-careful close to an ATZ, the highest rates of potential mid-air collision are in the vicinity of aerodromes, maintain a very good lockout.

Threat 1 – Needing to enter the ATZ. Management – preparing communication details as part of the PLOG.

Threat 2- greater chance of MAC. Management – monitoring the radio for local traffic and enhanced lookout.

Figure 3

However, you choose to route you must stay out of the ATZ unless following the requirements for ATZ entry which are published in Rule 11 of The Rules of the Air Regulations 2015. A brief summary is as follows:

  1. An aircraft must not fly, take off or land within the ATZ of an aerodrome unless the commander of the aircraft has complied with paragraphs 2, 3 or 4 as appropriate.
  2. If the aerodrome has an air traffic control unit, the commander must obtain the permission of that unit to enable the flight to be conducted safely within the ATZ.
  3. If the aerodrome provides flight information service, the commander must obtain information from the flight information centre to enable the flight to be conducted safely within the ATZ.
  4. If there is no flight information centre at the aerodrome the commander must obtain information from the air/ground communication service to enable the flight to be conducted safely within the ATZ.

In addition, the commander of an aircraft flying within the ATZ of an aerodrome must —

  1. cause a continuous watch to be maintained on the appropriate radio frequency notified for communications at the aerodrome; or
  2. if this is not possible, cause a watch to be kept for such instructions as may be issued by visual means; and
  3. if the aircraft is fitted with means of communication by radio with the ground, communicate the aircraft’s position and height to the air traffic control unit, the flight information centre or the air/ground communications service unit at the aerodrome (as the case may be) on entering the aerodrome traffic zone and immediately prior to leaving it.

Although you might find the route easy to follow and manage a straight line all the way to Sywell it’s worth considering preparing for a less than ‘ace-like’ flight and as you approach East Midlands airport listen out on 134.180MHz and set the Frequency Monitoring Code (FMC) of 4572 on the transponder.. If for any reason you do get “unsure of position” or even “sure of position, but actually in the wrong place” you can get instant help from East Midlands ATC; even if you don’t realise that you may be about to infringe they can call you and offer help. FMCs are a great idea and have helped many pilots to stay safe.

Threat – Potential to infringe East Midlands. Management – set FMC and monitor East Midlands.

Figure 4

As you approach Sywell your route will take you close to Husbands Bosworth gliding site. The threat here is not an infringement as such, but you will note from the legend that gliders are winch launched to 3,600 feet above mean sea level. You don’t want to get entangled in a winch cable, so make provision by routing clear.

Threat – winch cables and gliders. Management – route clear

Figure 5

You will have made your plan for the approach to Sywell before you set off. A radio call in good time to announce your intentions and check no change to airfield details and you make a text-book arrival and landing. All is well and you can look forward to the flight home.

Threat – a change of runway, circuit wind at Sywell. Management- a timely call giving you an opportunity to prepare for any change.

As part of the planning, don’t forget that temporary airspace may be active along the route and it won’t be shown on the chart. The temporary airspace may be a Restricted, Prohibited or Danger area. During a normal summer period there are many Temporary Restricted Areas (RA(T)) put in place to protect air displays. With the significant increase in the use of drones we are seeing many Temporary Danger Areas (TDA) being established. Use the NOTAM system to advise you of these areas. Mark them on your chart and have a plan to avoid them. Threat – unusual or temporary activity, Management – NOTAM check ad plan. Just before you start the engine, make a quick telephone call to the NAIS AIS Information Line on 08085-354802 or +44(0)1489-887515 for the latest information on the last-minute establishment of restricted airspace.

The CAA now positively encourages the use of GPS enabled VFR moving maps to enable better navigation and reduce airspace infringements. However, as good as they are, if not used properly they are not the silver bullet. There have been many airspace infringements by pilots carrying a moving map with an airspace warning facility. For several reasons the warning has either been ignored or missed. Aural warnings in a noisy cockpit are often not heard; linking the system to an intercom or by Bluetooth to a headset would help overcome that problem. Visual warnings need to be seen by the pilot and so they must pay attention to every part of the screen to make sure that a ‘pop-up’ warning is not missed. Obviously this can have its own problems in taking the pilot’s eyes into the cockpit when he might prefer to be looking out. The moving map should be treated as a tool to be used in flight and during planning. Precisely how it will be used in flight should be part of the flight planning too.

This useful advice should be used in conjunction with the aid memoir at Avoiding airspace infringements and at Threat and Error Management. There is a lot more information about how to plan not to infringe on this website.

07. Contingency planning

What happens when it all goes wrong?

Sections 5 and 6 focused on route planning, preparation and the application of Threat and Error Management in your route planning, but what happens when things begin to go wrong?  Every pilot knows the value of contingency planning. Most will have in their mind a pre-take-off brief; what happens if the engine stops at 100 feet, 500 feet etc. We are also taught to contingency plan in case of en-route engine problems, communications failures and diversions as part of our fundamental flight training.

How about contingency planning when it comes to airspace structures, particularly if one becomes “temporarily unsure of position”? A recent infringement occurrence (narrative 7 at Infringement occurrences ) explains the situation of a pilot who had done everything right in terms of their pre-flight navigational planning, but then infringed controlled airspace after misrecognising a navigational feature and changing heading too early. I am sure we have all been in similar predicaments, likely with less embarrassing outcomes. What would you have done in similar circumstances? Here are some things to consider.

Turn away

It sounds logical, but hard to do in the heat of the moment. If one is unsure of one’s position it doesn’t make great sense to turn towards a known area of controlled airspace. It might be better to hold one’s existing heading or even retrace one’s steps, even flying a reciprocal heading to one’s previously noted waypoint on the pilot log (PLOG). If one is approaching a likely area of controlled airspace on the nose, a clearly defined turn away might also reduce a worried controller’s blood pressure!

It’s Good to Talk.

Clearly, making contact with the air traffic unit would have been a good idea, but in the case recently highlighted the pilot was monitoring the nearby controlled airspace frequency and displaying the correct ‘listening squawk’ conspicuity code on their transponder, but apparently could not contact the air traffic service provider due to frequency congestion. What would you have done?

One contingency might be to call “D&D” in 121.500MHz. CAA advice is that “Any pilot who believes they are lost or temporarily uncertain of position should immediately seek navigational assistance from the appropriate radar unit. Alternatively, they should select code 0030 (FIR Lost) and contact D&D (callsign “London Centre”) on 121.500MHz for assistance.”

Take 2

When routing near controlled airspace the risk of unintentional infringement is demonstrably reduced when pilots plan to remain clear of the horizontal and vertical boundaries of the airspace by a suitable distance that’s appropriate for them, their aircraft and the prevailing conditions.  As a general rule of thumb ‘Take Two’ (i.e. 2 nautical miles horizontally and 200 feet vertically) is sound practical advice, but in some cases it might be prudent to allow even more.  After all, it only takes a small distraction, a moment’s inattention or a bit of turbulence in the atmosphere to gain a hundred feet or more.

In addition, if you need to fly close to the boundaries of CAS then it is strongly recommended that you contact the ATC unit that is controlling the airspace and announce your intentions.  In so doing your aircraft becomes ‘known’ traffic thereby removing uncertainty about its subsequent flight path from the controller’s mind. If you are unable to contact ATC or you don’t want any type of service then it is really good practice to use a Frequency Monitoring Code. The next two sections will cover these aspects in detail.

Electronic Aids

Of course, a potentially obvious answer to much of the above, is “use a moving map”. These days even in the worst of circumstances, some positional awareness can be gained on a mobile phone, even if only Google Maps.  Of course, over-dependence on such equipment also comes with the risk that these wonderful devices may ‘die’ at the most inopportune moment.  Keeping an up-to-date manual PLOG record of headings, waypoint and timings on a kneepad, or even written on your chart, both provides a contingency backup and may also provide additional situational awareness that might help you avoid trouble in the first place.

08. UK Flight Information Services (UK FIS)

As already highlighted in a previous article in this series an essential part of planning is to know which Air Traffic Service Units (ATSU) are available along your route, what they can offer you and to consider what you want from them.  Some pilots don’t like speaking on the radio and will try to operate non-radio for the whole of their flight allowing great freedom to enjoy the views of the terrain below and the view ahead.  However, the amount of regulated airspace in some parts of the UK may make it increasingly difficult at times but let’s assume we’re happy to use the radio; what services are there out there and how do they differ?

Many GA pilots comment that UK FIS is complicated, but perhaps it’s more confusion as to what services can be provided, who by and how they differ when in the air? The services available are Basic, Traffic and Deconfliction. Requesting and agreeing a service with the controller can take time depending upon the traffic density and controller workload. The task means it is not possible to be totally prescriptive about all actions to be taken with unknown traffic.  The controller is required to obtain a readback from the pilot of the service being provided – the verbal agreement is a contract so there can be no misunderstanding as to pilot expectations and controller’s obligation.  UK FIS is for the benefit for all pilots operating outside of controlled airspace.

Basic Service

As the name suggests, the ‘Basic Service’ is the most fundamental service available from the Flight Information Service Officer (FISO) or Air Traffic Controller Officer (ATCO).   A ‘Basic Service’ does not require the use of radar-based surveillance equipment for it to be available.  The provider is not required to identify you and is not required to monitor the aircraft’s position using radar.  The ATCO or FISO will not issue any executive instructions.  All the information pilots give will help the FISO or ATCO form a ‘mental picture’ of the traffic, whilst the use of charts will help predict the intended route in relation to airfields, controlled airspace, danger areas and other key areas.  The FISO at London or Scottish Information may ask you to select a squawk code to highlight to adjacent units that you are in contact with the FISO at the centre.  Similarly, an ATCO at a non-radar equipped aerodrome will provide local information relative to the aerodrome, approach procedures, local airspace and navigational aids, all pertinent to flight safety. Some may issue unit conspicuity squawk codes to highlight to local radar units the aircraft is receiving a ‘Basic Service’ from that unit. The principle is the same for a controller at a radar unit; it does not mean the aircraft’s position or level will be monitored.   It is a unit specific conspicuity code and not to be confused with the 7000/2000 conspicuity code or the unit’s Frequency Monitor Code (Listening Squawk).

Perhaps the key difference and advantage of a Basic Service over the Frequency Monitor Code is the provision of an ‘alerting service’. If something should go wrong it is far easier  to provide assistance to a pilot if they have already called in on the frequency and the basic flight details are known compared to an aircraft suddenly trying to make an emergency transmission on the frequency they are monitoring when a problem arises. The alternative of transmitting on 121.500MHz and selecting an emergency code on the transponder is always there ensuring an immediate response and assistance from the Distress & Diversion at London Centre.

As highlighted in a previous article, the FMC has its uses, especially around controlled airspace to assist with reducing airspace infringements. When receiving a ‘Basic Service’ avoiding other air traffic is solely your responsibility as the pilot; sometimes generic traffic information may be provided by the controller, depending on workload.  Under a ‘Basic Service’ some air traffic units may, subject to controlling capacity, offer warnings of a possible impending infringement (defensive controlling), if they observe your position and track in relation to controlled airspace boundaries.  There can be no guarantee that you will always be warned of such if controlling capacity does not permit.  Remember that you remain responsible for your own navigation and for obtaining a clearance to enter controlled airspace.

Traffic Service

The ‘Traffic Service’ requires the aircraft to be identified and level verified, requiring radar-based surveillance equipment to be available for the service to be available from the controller.  A ‘Traffic Service’ can be requested for either VFR or IFR flights with traffic information being passed in terms of bearing, distance and level (if available) of the conflicting aircraft with an indication of track.  The service can be provided below terrain safe levels with pilots being responsible for terrain clearance. Once a request for a ‘Traffic Service’ has been agreed there is the potential to be passed information on multiple aircraft. Although helping situational awareness this can increase your workload as you try to see the aircraft and acknowledging the controller’s messages can become a distraction from monitoring altitude, track and engine instruments. The controller will not provide avoidance advice and is not required to provide an update unless you request it. The controller may provide an update if, in their opinion, the situation requires it; this is where their judgement is required and introduces the ‘duty of care’ aspect. ‘Deconfliction’ is not provided to aircraft receiving a Traffic Service.  Although operating under your own navigation the controller may provide headings for the purpose of positioning, sequencing or as navigational assistance.  As a pilot you may alter your track, but you should not change your general route or manoeuvring area without first advising the controller and obtaining a response.  As a pilot, you remain responsible for traffic avoidance.

Deconfliction Service

Providing a ‘Deconfliction Service’ from the controller perspective can create a high workload depending upon the area where the service is required.  In addition to providing a Basic Service the controller provides specific surveillance derived traffic information and issues headings and/or levels aimed at achieving planned deconfliction minima, or for the positioning and/or sequencing. Once again, traffic avoidance is ultimately your responsibility and there is a minimum level at which the controller is permitted to provide the service, based upon the unit’s terrain safe level and radar coverage.

Some units may limit the lower level which they are permitted to provide a ‘Traffic Service’ and ‘De-confliction Service’.  Some units may have poor low-level coverage in certain areas requiring the imposed level restriction or when operating close to other aerodromes or high-density traffic areas where traffic may appear at short notice especially if climbing into radar coverage from below.

Specific units are paid to provide the Lower Airspace Radar Service (LARS) and provide UK FIS.  Radar equipped units who are not LARS providers (Figure 1)  may elect to provide a service to aircraft in their immediate vicinity to assist with the mitigation of airspace infringements and enhance safety.

Figure 1

Operational hours

The past year has meant many units have revised their operational hours due reduced traffic levels and reduced the available services with staffing restrictions in control rooms.  This was especially noticeable during the ‘lockdowns’ when GA activity was minimal.  Therefore, the available services may be restricted for some months as operational control rooms continue to maintain social distancing restrictions and hygiene protocol with less staff available.  A NOTAM check should make us aware of those units with revised operational hours and ensure none of us are surprised when enjoying the blue skies again this summer.

More information is available in CAP774 and CAP1434 – Flight Information Services.

09. Incorporating Frequency Monitoring Codes into your planning

As part of your planning it is essential that you know which Air Traffic Service Units (ATSU) are available along the route, what they can offer you and consider what you want from them. The suite of services available are detailed in CAP774: UK Flight Information Services.

It is always good to obtain a service from a Lower Airspace Radar Service (LARS) unit for a variety of reasons ranging from traffic avoidance/warnings through navigational assistance to a ‘comfort blanket’. On occasions obtaining a LARS may not be possible either due to the geographical location of the flight or time of your flight or indeed it may just not be wanted. When you are operating close to controlled airspace (CAS) and operating autonomously, it is good practice to monitor the relevant ATC frequency. By doing so you will develop situational awareness of traffic under a service and also traffic landing at, or departing from, the airport that the CAS serves; you will also get updates on the relevant QNH and may hear warnings of developing/changing weather.

Rather than operating autonomously and squawking conspicuity (7000 or 2000), you are encouraged to select the most relevant Frequency Monitoring Code (FMC), colloquially known as a Listening Squawk, of the nearest appropriate ATSU to indicate that you are monitoring that unit’s frequency. A handy A5 card detailing the 26 codes and frequencies is available on this site at Frequency Monitoring Codes (Listening Squawks)

When you are creating your PLOG and Frequency Card for the flight, add the FMC details so that are close to hand.  When using the Pilot Log on a Moving Map they are included in the frequency section for a flight from Lee-on-the-Solent to Coventry. (Figure 1)

Figure 1

Whilst you will not be in receipt of any service under UK FIS, the use of an FMC helps in preventing and mitigating the consequences of airspace infringements for both you and ATC. This works by allowing the Air Traffic Controller (ATCO) to be aware that you are on their frequency and enables them to quickly contact you if you are infringing ,or are likely to infringe CAS (if ATCO workload permits) thereby allowing an actual or potential infringement to be resolved quickly and effectively before it becomes a more serious incident. Although some ATSUs may, subject to controlling capacity, offer warnings of a possible impending infringement (defensive controlling), there can be no guarantee that you will always be warned of such if controlling capacity does not permit. Remember that you remain responsible for your own navigation and in particular for obtaining a clearance to enter controlled airspace.

If you intend to use an FMC, you should:

  • select the ATSUs radio frequency and check the volume BEFORE selecting the appropriate FMC;
  • select the FMC using ALT (Mode C) if the transponder is so equipped;
  • listen out for any transmissions with your callsign or position.

If both the aircraft and ATSU are equipped with MODE S, you will most likely be issued a warning based on the aircraft’s registration/callsign. If either/both of the ATSU and the aircraft is/are not equipped with MODE S, you will be issued with a warning based on the aircraft’s position.

“Have you turned the volume up?” It is not unusual for ATSUs to report their inability to establish 2-way contact with pilots of aircraft displaying an FMC who are just about to or have already infringed. This is invariably due to the volume having been turned down in the aircraft’s radio often due to radio comms impacting on instructional tasks or general chat with passengers. It is essential that prior to selecting the SSR code, the radio is set to the relevant frequency and the volume checked.

It is important that you also consider other aerodromes’ traffic when planning who best to listen to/communicate with; sometimes temporarily changing from an FMC to a local aerodrome’s frequency will mitigate the risk of mid-air collision. For example, when flying past the southeast corner of the Birmingham CTA in the vicinity of Coventry, rather than ‘skirting’ around the edge of the Coventry ATZ whilst operating on the Birmingham FMC/frequency, it is good airmanship to give the Coventry AFISO a call to improve your situational awareness of traffic operating into or out of the aerodrome; by doing so you will reduce many risks to you and other traffic, and remember Take 2 very much applies in this instance.

The areas’ lateral limits are also notified by their coordinates in the relevant aerodrome/airport entry in the Aerodrome sections of the UK AIP at AD 2.22; an example for Birmingham Airport’s FMC area is at Figure 2. A chart depicting all the areas of UK FMC can be found in the UK AIP at ENR 6.80 (Figure 3).

More details on FMC can be found in the YELLOW Aeronautical Information Circular (AIC) Y085/2020 entitled THE USE OF FREQUENCY MONITORING CODES IN THE UNITED KINGDOM FLIGHT INFORMATION REGIONS which is found on the NATS AIS website. This AIC details how to use FMC, lists all codes and associated frequencies and a chart extract from the UK AIP ENR 6.80.

Figure 2

If you are flying a non-transponder equipped aircraft, you are also encouraged to monitor the relevant ATSU frequency whist operating close to CAS. If a non-squawking aircraft is infringing or about to infringe, ATC will attempt to resolve the situation by making a ‘blind transmission’ with the aim of establishing two-way contact with the pilot.

It may be of concern to some pilots that if all pilots adopt FMC then the situational awareness is lost as there will be less communication on the frequency with many pilots just listening to the frequency and thereby giving a false sense of security that there is little traffic in the area when the opposite could be true.  However, there needs to be a fine balance between a congested frequency with multiple aircraft requesting a Basic Service or multiple aircraft on FMCs; one aspect that may assist your consideration and decision making is your equipage with Electronic Conspicuity devices that also offer you increased situational awareness.

Figure 3

Keep reading

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Guidance from ATC

Denied airspace access?

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