Confidential Human Factors
Incident Reporting Programme
The Charity
Aviation
Maritime
GA1304
Initial Report
ATC correctly advise GA traffic to avoid Lasham during gliding activity. However this does create a GA hotspot near HANKY [an IFR routing point – see diagram for approximate position on the VFR chart] as North-South and South-North GA tend to move as far as possible west, and climb, while also avoiding any possible Southampton CTA infringement. I departed VFR from Gloucester towards Chichester, en route to Lydd. I had selected this southern route to avoid the new Farnborough CTA, while appreciating that (anecdotally) other GA may also now avoid the Sevenoaks-Farnborough corridor and thus increase GA traffic routing South and North around London/ Gatwick. At 3600ft, I heard Farnborough ATC giving warnings of gliding activity at Lasham. I therefore climbed to 4700ft near Popham, but subsequently had to descend to avoid cloud and to get below the 4500 CTA. Having a PowerFlarm portable PCAS1, I was reasonably confident of the ‘PCAS’ alerting me. When near HANKY I was alerted by Farnborough ATC of an aircraft at my 12 o’clock, i.e. from the South East, but at unknown altitude. Turning left (East) was unsafe both due to gliding and because the approaching aircraft might turn right (East). Because turning right (West) could take me into a Southampton CTA infringement, I took the only available option and descended. When SE of HANKY and descending to 3600ft, the approaching aircraft appeared from cloud at an estimated 500ft directly above and no more than 0.3NM range. Clearly the other aircraft was skirting HANKY, as I was, in order to avoid Lasham gliders and the Southampton CTA. The ‘PCAS’ had only briefly flickered red but this was invaluable and timely.
I recommend considering a low level GA VFR route West of HANKY for glider avoidance, i.e. to separate GA and Lasham gliders, e.g. through the Southampton CTA along the line between West Meon Cross roads VRP and Burlington Cross VRP. Such a GA-only, low-level VFR route through the NorthEast section of the Southampton CTA could reduce risks during gliding activity at Lasham. The incident re-emphasises the importance of using ‘PCAS’, as already encouraged by CAA.
Footnote 1. In fact although PowerFlarm and PCAS (Portable Collision Avoidance System) perform similar functions, they are distinctly different systems. PCAS is similar in function to the industry standard commercial system TCAS (Traffic Alert and Collision Avoidance System), whereas PowerFlarm is an extension of the Classic FLARM system to incorporate transponder Mode-S and ADS-B detection.
CAA Comment
CHIRP Comment
Airspace in the south of England can be extremely busy, and this report describes well how the need to avoid controlled airspace can sometimes lead to the funnelling of aircraft near to particularly busy locations. The problem with setting up low-level corridors is that they can also end up funnelling aircraft into the same airspace and have the opposite effect to that intended; whilst a corridor would help with glider deconfliction if they were excluded (which in itself would be contentious to the gliding community), it would likely increase GA confliction by introducing head-on conflicts between opposite-direction traffic. There’s also no obvious line feature to follow in this case, which might pose navigation challenges to some. Furthermore, low-level corridors such as proposed are likely to be Class D airspace and therefore potentially subject to transponder requirements. All-in-all, setting up a low-level corridor might cause more problems than it might solve. The Solent CTA has a base of 2500ft west of ‘HANKY’ (see diagram) and so there is plenty of space below this for GA aircraft to route without the need for a specific corridor connecting the suggested VRPs. Nevertheless, CHIRP agrees that the introduction of new airspace formally needs to consider the likelihood of introducing such pinch-points as part of the CAP1616 airspace change process (which is not the case at the moment).
The Farnborough airspace change raised many concerns and we are due a post-implementation review to determine what have been the positive and negative effects of its introduction; CHIRP will add its voice to others seeking a review soon. As part of this, it’s important that pilots properly log any problems they have encountered in accessing the airspace, and this can be done using CAA form FCS1522 ‘UK Airspace Access or Refusal of ATS Report’.
Finally, whilst the report is of interest to CHIRP in airspace terms, remember that any Airprox should in the first instance be reported to the UK Airprox Board (UKAB) who have access to the tools (radar and audio recordings etc) and connectivity to NATS/CAA to conduct a thorough review of the circumstances in order to provide an objective analysis. The reporter’s carriage of electronic warning equipment is to be applauded, and readers may wish to note that the CAA have recently extended their facility for part-funding the purchase of such equipment by GA pilots.