Engine
Failures (12). These cover
the range of GA engine types and in 6 cases the report was of rough running or
loss of power but not complete failure. The reports seldom include the causes or remedial actions taken. I am always suspicious of of spark plug
change as rectification, believing that plugs are more often a symptom than the
cause.
Radio
Failure/Loss of Comms (5). The causes of communication failure are many and various; it takes time
and considerable distraction to identify the problem and take appropriate
action. Some of the causes can be:
If the VHF set in use has itself failed, one of the least
common causes, it will be apparent because the lights or display will
disappear. Other failures are harder to detect:
Headset failure, loose plug or socket. A spare headset within reach is very
useful. If the headset is not receiving,
selecting VHF audio to speaker until the problem is resolved can be very
helpful.
Transmit switch failure is not uncommon. Try using the other pilot’s headset reaching
across to use that Tx button.
Wrong frequency selected – 2 reports.
Complete electrical failure.
EFIS
Altimeter Malfunction. One
report states that the autopilot upper modes disengaged and would not
reset. The autopilot was disconnected
then re-engaged successfully. Meanwhile
the altimeter pressure setting reverted from 1013 to the previously set
QNH. If the cause of the AP failure was
a temporary loss of electrical power, could this cause the altimeter pressure
setting to revert?
Wake
turbulence (2). In both cases
under IFR this caused a rapid rolling movement although correct separation had
been applied. In one case the traffic
concerned was thought to be 1,300ft above and a few miles laterally. The heavy
aircraft types concerned were not mentioned.
Altimetry (5). Two aircraft climbing to a FL had not set
standard 1013 on the altimeter. Two
aircraft departed with the wrong QNH set.
NOTAM (3). Occasions of misreading of NOTAMS
might be reduced if providers applied a filter applicable to the route and
aircraft type entered. If the pilot is
flying a PA28 from EGHH-EGLK they don’t need to know about overflying the ME or
airline cabin procedures. If using Sky
Demon it is important to set the correct date and time, failing to do so has
led to danger area and RAT infringements.
Six
Aircraft in the circuit and joining. This
at a busy GA airfield adjacent to and underneath CAS. Seems rather a lot!
Crossing
ATZs. It is legal to cross an
ATZ if the pilot notifies this intention before entering the ATZ and again when
clear of it, but because something is legal does not mean it is safe or
advisable. The A/G operator or FISO are
not authorised to issue clearances, in many cases cannot see large parts of the
circuit and have no radar. It is
reasonable to assume that in good weather any GA airfield is going to be pretty
busy. Military airfields may be closed
at weekends, but it is wise to assume the ATZ is permanently active; they often
have gliding or light aircraft activities. RAF Ternhill is one such aerodrome. It has been reported several times that due to frequency congestion the
joining or transiting aircraft could not announce their intention. If in transit it may be better to avoid the
ATZ laterally, if joining do not enter the ATZ until radio traffic permits.
Collecting
Aircraft from Maintenance. This
topic came up at a local safety meeting and one report refers in the January
listings. When collecting an aircraft
from another airfield after heavy maintenance it may very probably not be ready
to fly, it is parked somewhere inconvenient, or the paperwork has not been
completed and it may require refuelling. It is almost certain that departure will not occur at the planned time,
so allow plenty for the flight back to base. If engineers are working, it’s better for the pilot to check paperwork
in an office or relax somewhere with a cup of tea, hovering nearby puts the
engineers under pressure and that is how mistakes occur. The pre-flight checks will take longer than
usual; this is the time when something will be different or not set as it
normally is. Is all the equipment you
expect to be on board where you expect it to be and stowed? Where is the tow bar? In a retractable, are
the gear pins in? In a fixed wing, check
the trim tab(s) for full movement in the correct sense; fatal accidents have
resulted from the tab being connected the wrong way round. It’s very unwise to plan this flight when
working against a time limit such as airfield closure, sunset or a commercial
flight following. For the flight itself,
failures or faults are more probable by a factor of several times; I cannot
list how many faults and failures have occurred after heavy maintenance, many
of them serious. Good flying conditions
are required. The report in this case
was a helicopter that had a gearbox oil pressure warning several minutes after
departure; wisely the pilots returned to land.
An Unusual Comment. A light twin departed and after a few minutes had to shut down the right engine for obviously genuine reasons. The return to land was safe and uneventful, having been handled professionally by the pilots, ATC and the RFFS. The ATC report included the sentence: “The PA34 is able to maintain flight on one engine such that any accident would likely have been minor”. Remember Kegworth?
Tow bars, Tie-downs, Filler caps and Gear Pins. Earlier months contained a few reports of aircraft departing with a tow bar or concrete block attached, filler caps loose or missing, engine blank or pitot cover fitted. An American magazine describes how a new and inexperienced owner of a vintage Cessna 170 delayed a planned flight due to weather and went for lunch with the instructor. The pilot diligently fitted the intake blank to prevent birds nesting while they were having lunch. After lunch, the weather had improved so they flew but failed to remove the blanks. The engine got cooked but it did not fail. One might suggest never getting into the aircraft to fly without at least looking at it and checking nothing is attached and the filler caps are on. Prioritisation of risk assessment is useful; what are the chances of birds making a nest while you have lunch? What would happen if they started to? What are the chances of forgetting about the covers you put on? Evidently much higher. One common solution is to have a big red card stowed in a seat pocket out of sight and place it on the pilot seat as soon as any form of cover is fitted.
Infringements (36)
The continuous work pattern of lookout, attitude and instrument (LAI) would indicate that the flight instruments should be glanced at every few seconds. Many altitude infringements occur because the pilot has not looked at the altimeter for much longer periods.In one case the pilot intentionally flew at FL90 because the on-board avionic system displayed the base of an airway as FL105 when it was in fact FL75. Acknowledging this fact, the CAA nonetheless cited the pilot’s lack of situational awareness. Legally, any infringement is the pilot’s fault.
After departure from an airfield beneath controlled airspace, the GPS failed and the pilot attempted to reset it. You know what happened next. A pilot on a local flight beneath CAS adopted a different route due to weather. While attempting to enter the new route into Sky Demon…you’ve guessed it again. The track pointer is very useful in such situations, just turn the aircraft until it points where you want to go is probably a much easier and safer method than spending minutes head down.
One reporter correctly observed that multiple audio and visual warnings from Sky Demon just led to repeated cancelling action. For decades since airliners were equipped with moving maps, EGPWS and TCAS, spurious warnings were very rare; I don’t recall any, which makes me wonder why a similar logic cannot be applied.
ATC unhelpful? One reporter receiving a basic service while flying at night in a helicopter had to deal with a flickering instrument panel light. While attempting to resolve the fault, the pilot climbed into CAS. In the pilot’s opinion, the ATC unit was not very busy, and thought that a warning could have been given. However, the controller could have been engaged on another task and for the minute or so that they were could have been more than enough time for an infringement to occur if they had no reason to anticipate it. Once an infringement has occurred a MOR has to be filed. It is all too easy to pass judgement on alternative courses of action in stressful situations from the comfort of one’s armchair, but the use of single pilot resource management might have helped here. Perhaps a call to the controller explaining the problem might have enlisted some help.
Multiple CAS Bases. One pilot flying a twin turboprop with inoperative autopilot eastbound to Duxford inadvertently infringed one of the bases that form part of the complex pattern of irregular and unmemorable shapes.
Graham Smith