Transponder Mandatory Zone (TMZ) infringement
The Stansted radar controller reports there were multiple aircraft inbound to London Stansted Airport landing on Runway 04. An aircraft (Cessna) was observed to enter the Stansted TMZ 2 with no Mode Charlie. The first inbound aircraft continued its approach as separation was increasing due to the speed difference. Two subsequent inbounds were issued radar vectors to remain clear of the infringing aircraft and traffic information was passed to the Stansted inbounds. The Cessna was traced using Mode S and the North Weald air ground operator was asked to transfer the aircraft to the Stansted Controller’s frequency to enable the arrival sequence to be restored. The Cessna failed to change frequency; one Stansted inbound was radar vectored to Runway 22 and the other was able to recover to Runway 04.
The Cessna pilot reports being on a local VFR recreational flight from North Weald to Duxford routing via the north of BPK. The pilot reports forgetting to check that Mode C (ALT) was selected before departing. The reported normal operating procedures for club aircraft is to always leave the ALT mode selected on. The previous pilot had not complied with this procedure and had selected ALT off. The operating pilot did not note the transponder setting and failed to follow the checklist prior to departure.
The CAA’s Infringement Coordination Group (ICG) noted that the Cessna flew into the Stansted TMZ 2 displaying No Mode C information resulting in an airspace infringement. This ensued from the pilot not selecting ALT on the transponder having failed to carry out correct pre-take-off checks. This simple, yet essential step when operating within a TMZ resulted in a significant increase in workload for the Stansted controller and the development of a complex traffic situation during a busy ‘arrival phase’. The ICG also commented positively on the pilot’s open and honest reporting.
SERA PART C – effective 12 October 2017
SERA.13001 requires the pilot of an aircraft equipped with a serviceable SSR transponder to operate the transponder at all times during flight, regardless of whether the aircraft is within or outside airspace where SSR is used for ATS purposes.
Stansted Control Area and Zone infringement
Avoiding Action by Commercial Air Transport
The Stansted radar controller reports observing an unknown aircraft track through the northern Stansted CTA (CTA 1) at 1900 feet and enter the Stansted CTR tracking in a westerly direction. Mode S identified the aircraft as a Cessna; a blind transmission was made in an attempt to establish communications with the infringing aircraft. A ‘check west’ was put in place meaning that all departures were suspended to the west; when the Cessna turned towards Andrewsfield, a ‘check all’ was put in place thereby suspending all departures. However, an eastbound departure was already rolling; on initial RT contact, the departing aircraft was given an immediate avoiding action turn to remain clear of the infringing aircraft.
The Cessna pilot reports being on a local VFR recreational flight from Andrewsfield routing to Bury St Edmonds, Newmarket and Sudbury and back to Andrewsfield to fly the hours required for licence revalidation. Despite reviewing the TAFs before flight, the pilot encountered deteriorating weather conditions on the first half of the flight; however, on turning to the next point, visibility improved so the pilot continued along the planned route. Along the sector, visibility deteriorated and a decision to return to Andrewsfield was made. The continued deterioration in weather resulted in the pilot being unable to recognise ground features that were expected. The pilot was not flying with a moving map and stated that a decision to abort the planned route was made too late.
The CAA’s Infringement Coordination Group (ICG) noted that the Cessna pilot lost situational awareness (SA) as to the aircraft’s position due to a deterioration in weather which resulted in an airspace infringement. When conditions deteriorated the pilot did not make use of one of 2 ATC agencies (Farnborough LARS or Essex Radar) or D&D to assist in recovery to Andrewsfield. Whilst it was felt that the route was planned effectively using a 1:500,000 Chart, insufficient Threat and Error Management was employed nor was the pilot using a moving map. The pilot’s honest reporting reiterated the need for moving map and not to get focused on fulfilling the task (in this case ‘hour building’) to the detriment of maintaining situational awareness. This was a prime example when the use of a moving map would have assisted the pilot in maintaining/recovering SA. In addition, early use of the Frequency Monitoring Code (listening squawk) for Stansted (7013) by the Cessna pilot on the inbound leg to Andrewsfield would have allowed the radar controller to resolve the airspace infringement at a much earlier point. Early avoiding action, to the departing traffic, by the radar controller prevented a loss of separation occurrence.
Solent Control Area infringement
Avoiding Action by Commercial Air Transport
The Solent radar controller reports observing an unknown aircraft northwest of the CTA (base level 2500 feet) tracking southwest towards controlled airspace on a definite course to infringe. Liaison was carried out with the Southampton Aerodrome Controller to give avoiding action to an aircraft on departure. Subsequently, the departing aircraft was given avoiding action by the tower controller to turn east. The infringing aircraft continued to track a further 3nm into the CTA prior to turning onto a north-westerly heading and leaving controlled airspace. The aircraft was later seen to select an adjacent LARS unit’s SSR code. Due to prompt avoiding action no loss of separation occurred.
The Piper pilot reports being on a local VFR recreational flight operating between 3000 feet and 4000 feet. The pilot was navigating using a 1:500 000 chart and was not using a GPS or moving map. The pilot decided to carry out an orbit over the radio telescope at Chilbolton to view the site; a gentle left-hand orbit was selected. The pilot added that a mistake was made in selection of the turn which resulted in the pilot infringing the Solent CTA; it was added that his could have been avoided by more detailed flight planning.
The CAA’s Infringement Coordination Group (ICG) noted that the Piper pilot did not carry out effective and thorough pre-flight planning and could have been better equipped for the flight; this resulted in a failure to avoid adjacent airspace whilst manoeuvring. This infringement occurred due to insufficient Threat and Error Management during the planning and execution phases of the flight. Had the pilot used of the Frequency Monitoring Code (listening squawk) for Southampton/Solent (7011), the controller could have employed ‘defensive controlling’ by warning the pilot that they were about to infringe. Alternatively, had the Piper pilot been in receipt of an ATS from one of the many Units in the area, a warning may have been given (NOTE. Under a basic service, a controller may not have identified the aircraft despite the pilot being issued with an SSR code). Additionally, the airspace in that location is complex with CAS, ATZ, MATZ and Danger Areas; the use of a moving map would have assisted in flight planning and alerted the pilot not only to notified airspace but also to the fact that the ‘gentle turn’ was ineffective in avoiding controlled airspace. Early avoiding action during a critical stage of flight, to the departing traffic, by the controlling team prevented a loss of separation occurrence.