Safety Matters and Safety Briefs are based on the AAIB Bulletin and UK Airprox Board reports, with additional material from the US National Transportation Safety Board.
Inexperience, wind and weather all take a toll, plus Airprox reports
Injured Injun-1 Aircraft Type: Piper PA-28 Cherokee 140 Date & Time: 11 February 2018 at 1143 Commander’s Flying Experience: PPL, 55 hours, 6 on type Last 90 days: 8 hours Last 28 days: 4 hours
This was the pilot’s first flight since the issue of his PPL and since completion of Piper PA-28 familiarisation training eight days previously (his student training was mostly on Cessna 152s). It was also his first flight with passengers and the first time he had flown with a rearseat occupant. He calculated that the aircraft’s weight would be a little less than MTOW and that its C of G would be near the middle of the permitted range.
Forecast wind at Southend Airport was 260/17kt, with gusts to 32kt from the same direction expected later in the day. Using Rwy 23, pilot and instructor were satisfied that the aircraft’s crosswind limit of 17kt for takeoff and landing would not be exceeded, nor the flying club’s maximum wind limit of 30kt for PPL aircraft hire. However, because turbulent conditions were expected, the instructor recommended that the Cherokee be landed using two stages of flap rather than three so that there would be no need to retract one stage of flap in the event of a go-around. He also recommended that the approach speed be increased by five mph to ninety, to provide a margin of safety if gusts were encountered.
After an uneventful local flight the pilot returned to land on Rwy 23 via a straight-in approach from 12nm out. He later described conditions as “choppy”, especially once below 1,500ft aal, with the strong, gusty wind leading to “a long and uncomfortable approach”. He set two stages of flap but forgot to add a safety margin to his airspeed, thus approaching at 85mph. At two nautical miles out he received landing clearance from ATC and was informed that the wind was 280/19kt.
Nearing the runway, the pilot thought he was below the ideal approach path but continued because he felt he could still reach the displaced landing threshold. Prior to touchdown he sensed a sudden gust blowing the aircraft to the left and it immediately hit the runway and bounced. He attempted to go around but the aircraft pitched up and, although he did not notice if the stall warning light illuminated, he realised that there was a danger of stalling. Before he was able to take any corrective action the aircraft sank quickly and struck the grass to the left of the runway, breaking off all three undercarriage legs, then skidded and turned right before coming to a halt facing towards the runway and resting on its left wing. Pilot and passengers escaped unaided and injured.
Airfield CCTV recordings indicated that the aircraft began to flare but, at approximately 20ft aal, it rolled left, and the rate of descent increased before it contacted the runway, having regained a wings-level attitude. It immediately bounced and climbed in a 25-30 degree nose-up attitude until it levelled for three seconds at 40ft with a reduced nose-up attitude, and as it descended towards the grass area south of the displaced runway threshold its rate of descent increased and the right wing dropped.
The instructor who had completed the pilot’s Cherokee training reported that the four approaches and landings that he had performed with him were “good” and this reflected the level of landing competency recorded in the pilot’s previous training notes. He had landed apparently without difficulty with a crosswind of 12kt from the right and in gusty conditions.
The flying club that operated the aircraft noted this was the pilot’s first flight with an aircraft close to its MTOW and with a rear seat passenger. He would thus have had to overcome a tendency for the aircraft to pitch nose-up because the C of G was further aft than he had previously experienced. The club is now considering introducing a requirement for newly qualified PPL holders to practice flying an aircraft at its MTOW with an instructor before flying solo with passengers.
The pilot thought he should have tried to gain more experience in various wind conditions before he carried passengers, and because he had flown a long final approach in turbulent conditions he had felt “unnerved” by the time he reached the airfield. He recognised that he should have gone around earlier, and when he did attempt to go around he should have concentrated on flying the aircraft rather than trying to communicate with ATC.
Injured Injun-2 Aircraft Type: Piper Cherokee Warrior II Date & Time: 16 November 2017 at 1141 Commander’s Flying Experience: PPL, 925 hours, 755 on type Last 90 days: 6 hours Last 28 days: 3 hours
When the pilot departed Wolverhampton (Halfpenny Green) Airport he was aware that there was a cold weather front to the northwest which was moving towards the airfield. Before taking off the Flight Information Service Officer informed him that the estimated wind was from 230/8kt. After leaving the circuit the pilot encountered deteriorating weather conditions including low cloud, rain, reduced visibility and turbulence. He told the FISO that he was returning to the airfield, and subsequently rejoined the circuit for Rwy 16, which has a landing distance available of 858m.
The pilot called downwind. After asking the him to report on final approach, the FISO noticed the wind had veered and told the pilot, then on final, that there was a tailwind estimated at 300/10kt. While transmitting this message the FISO saw the aircraft flying at about 10ft aal more than halfway along the runway. It touched down adjacent to the Precision Approach Path Indicators for Rwy 34 which are 393m from the stop-end of Rwy 16.
According to the pilot the aircraft seemed reluctant to descend while on final approach, but he did not remember hearing the FISO inform him of a tailwind. Visibility had reduced because of rain, but he appreciated that he was still airborne when more than halfway along the runway. His passenger, a former flight instructor, twice suggested that he went around, but the pilot continued because he still believed he had sufficient runway available to complete a landing.
After touching down, the pilot had difficulty slowing the aircraft due to the wet surface and tailwind so he increased power and attempted to go around. Once airborne, he was aware of the left wing dipping, probably because he had not applied sufficient right rudder to counteract the increased engine torque, and the left wingtip then struck a boundary hedge. The aircraft then lost height and hit a second hedge and fence, whereupon the left wing detached, and it spun around and stopped abruptly. Both occupants suffered minor head injuries.
A senior flight instructor at the airfield when the aircraft took off reported that the weather was deteriorating, the sky darkening and it was drizzling. When he heard the crash alarm, he noted that it was raining and estimated from the windsock that the wind was from 340/15kt. The sky cleared and the rain stopped a few minutes later. Given the position of the windsock, he concluded that a pilot approaching Rwy 16 might have found it difficult to discern that it was aligned in the reciprocal direction to that expected.
The AAIB comments: ‘The CAA’S Skyway Code (CAP 1535) reminds pilots that they are required to consider the meteorological situation before commencing a flight. A section titled ‘Pre-flight Preparation’ informs pilots that the Met Office is the main source of aviation weather information in the UK, and the document provides detailed guidance to help them interpret charts and codes. It stresses that pilots should have a good working knowledge of the conditions associated with common weather features such as warm and cold fronts. CAA Safety Sense Leaflet SSL 1e Good
Airmanship addresses many aspects of general aviation flight and tells pilots to: ‘Get an aviation weather forecast, heed what it says and make a carefully reasoned go/no-go decision’ and ‘Go-around if not solidly on in the first third of the runway, or the first quarter if the surface is wet grass.’’
CHIRP addresses GA pilot training issues
CHIRP has briefed the CAA on a number of pilot training issues. ‘While some of the themes reflect pilot inexperience, it is possible that others reflect gaps in knowledge that could and should be covered in ground school or during airborne training,’ it says. Themes identified included:
• Inadequate flight planning with a lack of contingency options for weather and/or airspace. Pilots not reading/ assimilating NOTAM information
• Lack of understanding about human factors – physiological and psychological. Pilots seem unaware of the IMSAFE mnemonic for assessing their fitness to fly
• Incidents while joining and flying in visual circuits regularly feature in CHIRP reports with some examples of pilots appearing to have little awareness of what is going on around them. Also an unwillingness to go around from unsafe approaches
• Contributing to the problems in the visual circuit, but also evident en route, use of r/t is sometimes poor. Some pilots do not appear to listen out adequately in order to build up their situational awareness; incorrect phraseology is common and clearances are not read back in full
• Misunderstandings about the provisions and differences between a Basic and a Traffic Service are common. Similarly the differences between an airfield Flight Information Service and an Air/ground Service, the latter compounded by some A/G Operators exceeding the terms of their Certificate of Competence
• Many GA pilots fly with GPS, ipads and other technology that can divert their attention from lookout into the cockpit. En route there is evidence of poor task management between the electronic aids, speaking to ATC, and basic navigation
• Fuel awareness often seems poor. Pilots do not dip their fuel tanks and over-rely on inaccurate gauges. Some reports concern pilots running out of fuel completely. Perhaps pilots learn to fly on aircraft types where the gauge can be relied upon before switching to types where the gauge is a guide only
• Pilots do not appear sufficiently defensive in terms of routeing over suitable areas for forced landings and in terms of being unwilling to give way to other aircraft when they perceive they have priority
• We believe pilots are not routinely taught how to look for hazards in the overshoot when they are selecting suitable fields for PFLS.
‘A recent report about a Flying Instructor (Restricted) supervising solo students highlighted a lack of information about the nature of supervision for restricted instructors,’ CHIRP notes. ‘There is no formal definition of the level or means by which the supervising instructor provides that supervision.
‘We periodically receive reports about solo students being sent on qualifying cross-country flights with barely sufficient time before destination airfields close or, in winter, daylight fades into twilight.
‘On the positive side, many pilots write to CHIRP about errors or misjudgements they have made with a genuine desire to help others avoid similar problems.
‘Sadly ‘turn back’ accidents following attempts to regain the airfield continue to haunt us, despite it being a feature of flying since the start of the last century. It’s the oldest killer in the book. Events last year tragically saw at least four such accidents culminating in death or life-changing injuries, largely as a result of partial engine failures… A ten-year survey of accidents in Australia showed that there were nine fatalities with partial engine failures and none with total engine failures. An analysis of the certainty of accident against remaining power output has indicated that if a pilot had between 25-75% power, the likelihood of losing control and a fatal accident was high. Pilots were tempted to turn back or have a go at a low-level circuit and ended up stalling/ spinning at low level, which is invariably fatal.
‘While instructors regularly teach ‘fan stop’ exercises, there is little or no emphasis on dealing with a partial or progressive loss of power. It is often harder to detect, and can leave a pilot with too many decisions to make. Perhaps greater awareness by the instructor community to this insidious killer may mean we can reduce the casualty rate in the coming year.’
At its April 2018 meeting the Airprox Board assessed 25 incidents of which nineteen were aircraft-to-aircraft, of which nine were assessed as having a definite risk of collision (two Cat A ‘where providence played a major part’, and seven Cat B ‘where safety was much reduced due to serendipity, misjudgement, inaction, or late sighting’).
Notes the Board: ‘The dominant themes were poor/ incomplete planning by pilots
who should have been able to avoid the resulting situation by applying more thought to their routeing or actions (eleven incidents); poor/incomplete situational awareness (also eleven), probably resulting from the former lack of planning in some cases; nine involving late- or non-sightings; pilots not fully following procedures in six incidents; in four events there was poor integration by pilots and/or controllers; and three where pilots could have asked for a better Air Traffic /Service (i.e. a Traffic Service) in busy airspace.’
The Board made three Ga-related recommendations during the meeting: ‘1: Lee-onSolent to include information in their AIP entry to highlight the possibility of glider traffic crossing the centreline and the existence of a glider landing strip on the north-western side of the main runway as a result of a glider crossing in front of a DA40 on finals; 2: The Avon Hang Gliding & Paragliding Club and SPTA Ops to refresh their LOA to cover usage of the Bratton launch site and how that information is conveyed after a [Royal Navy BAE] Hawk pilot flew through a number of paragliders that he didn’t know were there’ (the report of this incident featured in the national press−ed); and 3: HQ Air Command review the radio procedures for CGS operations from Syerston after a tug/ glider combination climbing to 6,000ft encountered a Piper Tomahawk orbiting at 3,000ft that was talking to East Midlands.’
Under the heading ‘It’s good to talk… and it can help if you’re on the same wavelength’ the Board asks, ‘How do you select the right Air Traffic Service in busy airspace?’ referring to an incident in which a Chipmunk and Cessna 172 on different frequencies came very close to each other near Luton.
The Chipmunk’s pilot was in a straight-and-level cruise and looking at a ground feature to his left. After about fifteen seconds he looked ahead and saw the Cessna 172 flying slightly lower in the opposite direction. He made a hard pull-up and the C172 passed below without appearing to take any avoiding action. The pilot assessed the risk of collision as “high” and said he had not been closer to another aircraft, apart from in formation, in forty years of professional flying.
The instructor aboard the C172 being flown by a student said that their aircraft was in a straight-and-level cruise when he noticed an approaching aircraft at 1 o’clock. He could see that it was going to pass to the right and above and that there was no risk of collision, but he was not comfortable with its proximity so he took control, lowered the nose, reduced altitude by 200ft and turned slightly left. As the other aircraft passed by he noticed that its pilot turned to his left. He pointed out the aircraft to his student and they later discussed the importance of the constant ‘Lookout, Attitude, Instruments’ workflow. The instructor said that at the time of the manoeuvre the other aircraft was far enough away that he could not observe any detail, such as colour, type or registration, but could only see a darkish, single-engine, low-wing aircraft. Because it was at a distance, the vertical separation was increased and there was no risk of collision, he did not deem it to be a reportable Airprox, so didn’t report it to Farnborough North.
‘In fact,’ says the Board, ‘we determined that the C172 had not seen the Chipmunk but a different aircraft further away just prior to (this) incident. The C172 was under only a Basic Service with Farnborough LARS, while the Chipmunk was on Luton’s Listening Squawk frequency. If they had been on the same frequency there was a chance they might have been aware of each other and, even better, if they had used a Traffic Service they would have received specific information.
‘This raises the old conundrum of whether Farnborough LARS could have given a service if they were busy, the very time that you really want one. The C172 pilot may not have asked for a Traffic Service because he was instructing, or might have thought that he wouldn’t be likely to get a service – but if you don’t ask, you definitely won’t.
‘The Chipmunk pilot’s decision to “listen out” with Luton meant there was little possibility of him obtaining Traffic Information while doing so because it’s only intended as a means of warning about nearby airspace that he might be about to infringe, not about other aircraft he might be in conflict with.
‘The Board acknowledges there were many factors in managing each sortie, and there was a balance to be made between using Frequency Monitoring Codes and LARS. Nevertheless, in conditions of less than ideal visibility, or for sorties involving a high workload or activities which might detract from an effective lookout (such as an air test or aerobatics), it is well worth requesting a Traffic Service if possible.’ airproxboard.org.uk
A timely go-around might have given space for weather consideration
Low hours, near MTOW and gusts took a toll
Airprox: using different frequencies