MEALL times
(Maintenance Errors And Lessons Learned)
M
usic maybe the food of love onto Yaks. It usually takes about 6 ly or not at all. Chances are that one
but experience is the staple hours because they are so different. I mag on any older aircraft will have
diet of avoiding mistakes. was about half way through a conver- been changed at some point, but if
In the interests of aviation safety we sion with a guy who’d just bought a not there’s the potential that both
will regularly report on maintenance refurbished Yak 18T when the engine mags may decide they’re not playing
errors, what was learned from them lost all power in the climb. I took at the same time.
and how they might be avoided. control, lowered the nose and started If you have an M14 engine, make
Please feel free to send your experi- looking for a field. Don’t you love sure the mags are under 20 years old.
ences to news@avmain-mag.com. those planners who allow houses to Otherwise change them. I’m having
People, companies and aircraft will be be built right up to the boundary of three mags on my next plane! Food
de-identified. an airfield? A powerless 18T glides a for thought perhaps.
bit like a brick with particularly poor
Double helping of mag failure aerodynamics. Human Factors Training - Do you
Virtually all piston aero engines have About 5-6 seconds later the comply with the requirements?
two separate ignition systems. The engine burst back into life and ran The majority of all aviation mainte-
idea is that if one fails, the chances of very roughly. I decided to fly a very nance incidents and accidents are the
the other failing is tiny, so the engine tight left hand circuit always keeping result of human error. New regulations
keeps going. Magnetos, wiring, spark within gliding distance of the airfield. have been established by the Federal
plugs etc are all duplicated for each I glanced across at my student. He Aviation Administration (FAA) and
cylinder. Exact chances of a double hadn’t broken a sweat. Cool guy. the European Aviation Safety Agency
failure are difficult to establish but After landing I asked the Russian (EASA) to require all aircraft personnel
must be millions to one. Such a failure engineer to investigate. This is what that are maintaining aircraft to have
on climb out at around 300 feet is emerged. After many years of use an in depth understanding of the role
what’s known as ‘very bad luck’. With and many cycles the mag coils on the that human factors play in the safety
any operator it happens perhaps once Vedeneyev M14 engines start to fail of the airline, maintenance, repair, and
in 20 years. It happened to me. when hot, probably due to shorting of overhaul industry. This can only be
When I’m not writing about aviation the windings. No evidence of this may achieved though an approved course
I’m usually doing it. My great love is be see on engine run-up at the hold, that certifies that the aircraft mainte-
the Yakovlev series of light aircraft but as the engine heats on climb out, nance technician has been formerly
on which I’m a class rating instructor. the mag coils will reach a temperature trained and is then compliant with this
I convert pilots from western types at which they either work intermittent- new industry standard.
EASA requires human factors train-
ing by American licensed A&P techni-
cians prior to them working on for-
eign-registered aircraft: “The person
shall demonstrate that he has received
training on human factors and airwor-
thiness regulations as detailed in Part-
66”. (Official Journal of the European
Union, Annex II, Part-145, 2003) “A
maintenance human factors training
program is required for those main-
tenance organizations seeking EASA
145 certification.” (Order 8300.10 FAA
bulletin, effective date 9.25.06)
In addition, the FAA is quickly
moving towards mandating
maintenance human factors in
aviation training as well: “...efforts
are underway to make human factors
training required” (Order 8300.10
One of the offending mag coils, the pilot (now calmer) and the aircraft in question.
FAA bulletin, effective date 9.25.06)
62 Aviation Maintenance | avmain-mag.com | December 2009/January 2010
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