Airprox

[thearb]

From this month's CHIRP:

AIRPROX
Report Text: I was PIC of a PA28 returning from [ ] to [ ]. My passenger, also a PPL holder, had flown outward.
On the first two legs of the return flight we were going directly into low sun and I had been flying mainly on
instruments due to the poor forward visibility, with my passenger performing lookout. I hold an IR(R). We had
been receiving a Basic Service and a new squawk. We were flying at 105 KIAS and 2700ft on the Brize QNH.
We were tracking the 162R outbound from DTY, which put the sun in about our 2 o'clock, improving forward
visibility significantly.
One or two minutes after the radar service changeover, at approx. 1447Z and 5 nm SE of DTY - roughly 3nm E
abeam Turweston, my passenger emitted a sudden exclamation and several expletives. I was confused as to
what his concern was for about 5-10 seconds; then I saw another [similar type] in my 9 o'clock flying directly
away from us and 50-100ft (estimate) below.
My passenger was quite shaken by the incident and said that the aircraft had appeared to be coming directly
at us and was close enough for the people on board to be visible. By the time I saw the aircraft the incident
was over and it was separating from us.
The other aircraft's subsequent movement suggested it may have been on a track of about 140 degrees. We
surmised therefore that it must have been approaching our starboard side from behind. The sun's position
meant that our starboard visibility was still poor.
No traffic information regarding this conflict was passed to us by Brize Radar. As far as we could deduce from
RT exchanges after the incident, the other aircraft was not on Brize frequency. We were unable to note its
registration. We considered it might have recently departed Turweston, but given our proximity to the airfield
we felt it unlikely that a PA28 could have gained sufficient altitude for the conflict.
I fully accept that responsibility for conflict avoidance is the responsibility of the PIC. However, we felt strongly
that as the other aircraft would have had the sun further behind it, our aircraft should have been much more
obvious to its crew than it was to us.
CHIRP – Confidential & Independent Reporting
CHIRP – Confidential & Independent Reporting - Page 3
Lessons:
1. Lookout in the vicinity of ground-based navaids needs to be especially vigilant.
2. My passenger admitted that he may have been momentarily distracted with inputting next frequencies after
the radar service handover.
3. A hand-held LPAT* is certainly worth considering.
[*LPAT: Low Power ADS-B Transceiver. (ADS-B: Automatic Dependent Surveillance – Broadcast). Hand-held,
battery-powered, supposedly “low-cost” receiver for airborne transponder signals. Technology apparently still
undergoing trials, nothing available yet, maybe next year. See Clued Up Spring/Summer 2015.].
CHIRP Comment: Airprox incidents can be investigated more thoroughly by the UK Airprox Board (UKAB) than
by CHIRP because the UKAB has ready access to radar and RT recordings and the resources to trace the pilots
and controllers involved to ask for their recollection of events. Nevertheless, from the CHIRP perspective there
are several aspects of the report that bear comment, including agreement with the reporter’s lessons identified.
It is not clear when LPATs might become available but we encourage the fitment and use of electronic
conspicuity and alerting devices The Airprox occurred in Class G airspace where the pilots in both aircraft
shared an equal responsibility to see and avoid other aircraft. The reporter did not see the other aircraft in time
to take avoiding action; without a statement from the other pilot, it is not clear whether he saw the reporter’s
aircraft and stood on his course, or whether he did not see the reporter’s aircraft in time to avoid it by a greater
margin, or didn’t see it at all. The reporter was in receipt of a Basic Service from Brize Norton. Under this
Service there was no obligation on the Brize ATCO to provide Traffic Information and he did not do so. In
conditions of poor visibility and/or busy airspace it is recommended to ask for a Traffic Service; if it is not
available don’t expect any Traffic Information under a Basic Service.


Full report here:

https://www.chirp.co.uk/upload/docs/General%20Aviation/GAFB%2068%20V1%20(Web).pdf

[thearb]

Airprox of the Month

Airprox report 2015169 deals with a close encounter between a PA-18 Piper Cub and a PA-28 Piper Cherokee 4 nm SW of Stapleford at Altitude 2000 ft. I have chosen it because it typifies the classic GA airprox (some of which end up as mid airs, and these are often fatal). The two aircraft were flying in opposite directions just to the SW of the Stapleford ATZ. at 2000 ft. They were in something of a pinch point with the London CTR a little further to the SW and the TMA at Altitude 2500 ft above them. They each saw the other aircraft too late to take avoiding action and passed with about 100 ft of vertical separation. The Airprox Board concluded that luck had played a  major part in the incident and assessed the degree of risk as A.
 
Both aircraft were receiving a Basic Service from Farnborough Radar and squawking with Alt. The Board refers yet again to the greater protection offered by a Traffic Service rather than a Basic Service and recommends always requesting this although it may be available only on a restricted basis or not at all. Above all else the Board emphasises the importance of prioritising lookout over in-cockpit and navigation tasks and the need to ensure that canopy obscurations are countered by moving one’s head around to search pro-actively for other aircraft.

Personally, I use a Personal Collision Avoidance System (PCAS) on our PA-28 in the form of a portable battery operated Zaon MRX. It detects only transponder equipped aircraft in sight of its aerial and presents only distance and relative height. However, a bleep from the box will immediately get you looking out with considerable diligence. My glider has FLARM which detects only other FLARM equipped gliders. It shows direction as well but if you are circling this becomes rather confusing. Anyway, it compels you to get looking out at once to identify the traffic. This sort of kit is no substitute for keeping a proper lookout, especially as it does not detect all traffic, but it does makes a valuable supplement. If one or both the aircraft in this airprox had been carrying PCAS there is a good chance that the incident would never have occurred.

http://www.gasco.org.uk/safety-information/flight_safety_extra_june_16/airprox_of_the_month.aspx