AirproxesThese are short and incomplete summaries only. Full reports are available on www.airproxboard.org.uk
6 August 2016
2nm East Bidford
|THE LS3 PILOT reports that she had just released from the tow at 2000ft and joined two other gliders established in a thermal. The cloud base was 4200ft and, as the gliders above neared this height, they left the thermal so that she was the only one left, climbing. On reaching about 2600ft, the FLARM indicated that another aircraft was behind and at the same level but she was unable to see it. She continued to circle left and, as she came round 180°, she could see a Dimona glider coming straight at her in her 12 o’clock. She dived below it and continued round, thinking that it was passing through. However, as she came round again through another 180° the same thing happened. She noticed that the Dimona’s propeller wasn’t turning, so it was clearly trying to thermal with her. She believed it was thermalling in the opposite direction to her. She decided that the only safe course of action was to leave the thermal.
THE DIMONA PILOT reports that at the time of the alleged Airprox he was within 1nm of Long Marston, operating as a glider and following standard glider procedures. He joined the thermal in accordance with the BGA guidelines and was fully visual with the other glider at all times. Being so close to Long Marston, he was on their published frequency of 129.82. He remarked that he was very surprised that this was reported as an Airprox because, as far as he was concerned, they were both following standard glider thermalling procedures. He has since been in contact with the CFI at Bidford gliding club and, during a face-to-face meeting, discussed how the two clubs could operate safely within such close proximity. It was agreed that, in future, Bidford gliders should broadcast on the Long Marston frequency when in the area.
THE BOARD had some difficulty in reconciling the two reports. Ultimately, the differing perceptions of risk in the reports (with one pilot very concerned, and the other not at all concerned) was troubling but, in the end, the Board agreed that it was for the Dimona pilot to join the thermal in such a way as to not cause concern to those already established in it, and they therefore assessed that the cause of the incident was that the Dimona pilot had flown close enough to cause the LS3 pilot concern.
23 August 2016
N of Keswick
|THE AS365 PILOT reports that he lifted from a HEMS site at Keswick and flew to the right of the Derwent/Bassenthwaite valley in a climbing right turn for best speed to get around Skiddaw to the hospital. Once clear of the mountain and on track to the hospital, a Mode A TCAS icon was spotted to the 12 o'clock. The aircraft was at 2nm and closing but was not seen at this time. He elected to completed an avoiding right turn into an area that he could see was clear. While conducting this descending right-turn, the small fixed-wing aircraft was spotted by the front left-seat occupant very close to the 10 o'clock below 1000ft agl. The small fixed-wing aircraft did not appear to see them and remained straight and level.
THE PA28 PILOT reports that the helicopter flew around from the blindside of the mountain. He saw it and then the helicopter turned right, closer to the mountain side. He did not take any action as there was clearly no risk of collision at that point.
THE BOARD quickly agreed that both pilots had seen each other as early as could have been expected in the circumstances. Notwithstanding the fact that the PA28 pilot felt that separation was adequate having seen the AS365 in a right-turn, some members felt that the PA28 could have turned right to increase the separation once he had sighted the AS365 given that he couldn’t know the AS365 pilot’s intentions. Ultimately, it had been the AS365 pilot’s turn away from the PA28 on receipt of the TA that had effectively prevented any risk of collision.
18 August 2016
|THE EUROFOX PILOT reports that he was towing a Puchacz sailplane from Saltby airfield and was in a gentle climbing left turn when a Cessna appeared in his 2 o’clock. He took immediate evasive action with a sharp right turn to pass behind the Cessna. He believes that if he had not done so the probability of a collision would have been very high indeed. Neither the pilot of the Puchacz (a very experienced instructor) nor he believes that the pilot of the Cessna saw the combination, even though they were quite close to the gliding club and in the Cessna’s 10-11 o’clock, out of sun and slightly low.
THE C152 PILOT reports that he was on the first section of his qualifying cross country flight. His route took him south to his first turning point at Belvoir castle, then ESE towards Bourne, his second turning point. It was on this leg that the alleged Airprox was reported, he planned to be no closer than 2nm from Saltby. He does not recall seeing any other traffic in his vicinity as he passed Saltby towards Bourne.
THE BOARD began by noting the C152 pilot’s inexperience and opined that he was potentially focusing on his navigation at the expense of lookout. Although members agreed that it was clearly the responsibility of the C152 pilot to avoid an aircraft towing another aircraft. Ironically, in looking towards Saltby to ensure he was giving the glider site a wide enough berth, the Cessna pilot may even have been looking away from the tug and glider at the critical time. The Board commented that a robust lookout was always required in see-and-avoid Class G airspace, not only when routing close to glider sites. Mindful that the C152 pilot was routing in the vicinity of Saltby glider site, members agreed that the C152 pilot had allowed sufficient margin from it. Turning to the EuroFOX and Puchacz pilots, the Board noted that they had been late in sighting the Cessna, possibly due to the EuroFOX’s high-wing configuration, and some members wondered if they had been somewhat task-focused too. Recognising that they were relatively non-manoeuvrable in their towing configuration, increased attention to lookout scan was desirable for both of them.
6 August 2016
1nm S Littlehampton
|THE JABIRU PILOT reports that he was in receipt of a Basic Service from Farnborough LARS East, the weather was CAVOK and there was no cloud in the vicinity. He had routed north of Shoreham ATZ then turned towards the south coast, when he saw a low-wing GA aircraft
almost directly ahead at a range of 200m; it was approximately 10ft above, just a few feet to his left and flying straight–and-level. He ‘threw’ his aircraft into a sharp right-turn to avoid an almost certain collision. He estimated he only had about 2 seconds to take the action, and it appeared the other aircraft did not take any action at all; it then passed down his left-hand-side. He noted that he was fully aware of the definition of a LARS Basic Service and in future would request a Traffic Service.
THE PA28 PILOT reports that he was routing inbound to Shoreham and had switched frequency from Farnborough to Shoreham. The traffic at Shoreham was busy and he was instructed to orbit in the Worthing area to start with. He proceeded along the coast heading 090° approximately 0.5nm out to sea. The oncoming aircraft was spotted about 0.5nm away at a similar altitude, and he commenced a turn to the right. The other aircraft turned steeply to the right and so he judged further avoiding action unnecessary. He judged that the horizontal separation was not less than 500m at any stage.
THE BOARD Noting that the position of the Airprox was on the very extremes of Farnborough radar coverage, and that the Jabiru pilot had already left the Farnborough frequency, the Board wondered whether he could have called Shoreham as he transited past rather than switch to Solent as they may have been able to give generic Traffic
Information on inbound aircraft. At the very least he would have been on the same frequency as the PA28, and may have heard a radio call that would have alerted him to the fact that it was transiting in the opposite direction. The Board noted differing perception of the PA28 pilot in the assessment of risk, and thought this was probably due to the Jabiru pilot being startled by the PA28, whilst the PA28 pilot had seen the other aircraft half a mile away and
felt that the separation was adequate. Nevertheless, the radar separation indicated that the two aircraft were at the same level and only 0.1nm (180m) apart rather than his estimate of 500m. As such, the Board wondered whether the PA28 pilot would have been better advised to have given the other aircraft a wider berth given that he could not know if the other pilot had seen him or not. The geometry being head-to-head, neither pilot had right-of-way and, without knowing the intentions of the other pilot or whether he was visual with him, they opined that pilots should always endeavour to ensure that there is a safe margin for error when passing another aircraft; a turn of a few more degrees taken earlier by the PA28 pilot would have more effectively broken the closing geometry.
2 October 2016
|THE C152 PILOT reports that they were in the visual circuit at Gamston, as they turned left-base the student spotted a drone, white in colour with a gold centre, in the 10 o’clock position. It passed below and behind and no avoiding action was taken.
THE BOARD noted that the drone was operating at approx 500ft, within Gamston ATZ without the permission of ATC; as such, the Board considered that the drone operator had endangered the C152 and its occupants. Therefore, in assessing the cause, the Board agreed that the drone had been flown into conflict with the C152. Turning to the risk, although the incident did not show on the NATS radars, the Board noted that the pilot had estimated the separation to be 400ft below the aircraft, and that the C152 pilot had not felt the need to take any avoiding action. Notwithstanding the difficulty of range assessment without visual cues, it was also agreed that the drone had passed sufficiently clear that there was no risk of collision on this occasion.