Qualified
And Authorised?
I once
read an annual report on a junior officer that said, ‘His enthusiasm
often outstrips his ability.’ I’m still not certain whether that
was a good report or a bad one! However, working on an aircraft or any of its
associated systems is no place to let one’s enthusiasm to get something
fixed go beyond your level of qualification and authorisation.
We have
probably all witnessed a helpful bystander offer to get his car to jump-start
an aircraft with a flat battery. Not wise. Better to have a qualified
engineer investigate why the battery is flat, rectify any fault and then fit
a fully charged battery before the next flight. How many missing fasteners on
your engine cowling are acceptable? Are you sure you have the correct type of
fastener to replace those missing? Why are the fasteners missing?
‘Modifying’ a component on an
aircraft is just another word for botching the job, unless you are qualified
and authorised to incorporate an authorised modification. Let’s look at an
accident that shows how serious the after-effects of a botched job on a piece
of aircraft equipment can be.
A young
and experienced glider pilot suffered serious injuries when he crashed into
trees close to his intended landing point at an airfield. The glider was
destroyed on impact. The left shoulder and lap straps of the pilot’s
harness were found to have disconnected from the quick release fastener (QRF)
during the impact, probably increasing the severity of the pilot’s
injuries. There was no evidence of damage to the strap fasteners.
The reasons for the
crash were identified by the British Gliding Association (BGA) and are
irrelevant to this discussion, which will concentrate on the reason for the
failure of the pilot’s safety harness.
The UK Air Accidents Investigation Branch
(AAIB) conducted an examination of the QRF rotary buckle and the rest of the
harness in collaboration with the QRF manufacturer’s representative in
the UK, an expert metallurgist and, subsequently, by returning the buckle to
its manufacturer in the USA.
The rotary buckle is a metal housing with
five slots to take the metal end fittings for two shoulder straps, two lap
straps and one crotch strap. These end fittings may be released by rotating a
four-vaned handle on the centre of the QRF clockwise or counter-clockwise,
thus unlocking the harness. The release mechanism for the crotch strap or
either of the lap straps may be deactivated so that the buckle remains
attached to one piece of harness when the QRF is unlocked. The shoulder
straps can be released separately by pushing forward on the tab located
between the shoulder strap end fittings. The QRF buckle is a sealed
construction and does not require internal checks or maintenance.
Each strap end fitting is retained in the
locked buckle by a restraining dog and a combination of
‘mushroom’ pins. Unlocking the buckle by rotating the four-vaned
handle retracts each restraining dog inside the QRF. The buckle failed by the
left-hand lap fitting pulling out of the buckle. For this to happen the
detached mushroom pin found inside the QRF could not have been in place at
the time of impact and physical evidence showed that it had been loose for
some time. The way in which the mushroom pins in the failed QRF were riveted
was compared to an example buckle from the same manufacturer. The method of
riveting on the example buckle was stronger and offered greater resistance to
pull-out.
The rotary
buckle manufacturer found that the buckle, manufactured more than 20 years
before the accident, did not match the rest of the harness. They made
negative comments on the apparent lack of servicing of the buckle, which had
become worn beyond the limits specified in the Component Maintenance Manual.
They also criticised the method used to attach the harness to the glider
fuselage structure. The webbing, the lap belt plug-in fittings and the
webbing adjusters were from at least one other manufacturer. The Gliding Club
stated that the harness had not been changed or modified since they acquired
the glider, complete with the harness, 5 years prior to the accident.
It does not seem unreasonable to assume that the QRF
buckle had been subject to an unauthorised repair some time in the past 20
years. It also seems that someone somewhere put together a seat harness from
bits and pieces of other harnesses. Finally it seems that the harness was
neither inspected nor serviced on a regular basis.
The failure of this harness highlights the
need to ensure compatibility between all the components of a harness and to
ensure regular periodic inspection and servicing.
The facts in this article are based closely on UK Air
Accidents Investigation Branch (AAIB) Investigation Reference EW/C2002/06/05
which source is gratefully acknowledged. The full report may be seen by
entering the above reference at www.aaib.gov.uk Any opinions
expressed are those of the author and are not intended to represent the views
of AAIB.
Acceptable
Risk & MAO
Risk
taking is an essential part of human life. There cannot be life without risk.
Western society seems intent on removing all aspects of risk from our daily
lives. The ‘no win – no fee’ litigious culture seems to
encourage us to blame anyone but ourselves for any mishap we suffer as we
blunder our way through life. Trip over an uneven pavement and sue the local
council instead of learning to look where you are putting your feet. Stumble
against a wall and sue the owner for having built the wall in the
‘wrong place.’ I believe this culture is weakening all of us and
is aiming at the unattainable goal of totally removing risk from everyday
life. These thoughts led me to the idea that zero risk is only available to
those who are already dead, so what level of risk is acceptable to those of
us who are willing to recognise and accept some responsibility for our own
actions?
Recent
research confirms that each of us has a slightly different perception of what
is ‘acceptable risk.’ It has been discovered that this variation
in perception is at least partly determined by the levels in our brain of a
particular protein called monoamineoxidase (MAO). This discovery may help to
provide one answer to some of the puzzling aspects of safety promotion and
accident prevention.
Research shows that the lower an
individual’s MAO level the greater is the level of risk deemed as
‘acceptable’ by that individual, and the higher the level of MAO
the less likely is an individual to take risks. It is hardly surprising to
learn that, in general, males have lower levels of this protein in their
brains than females. Also that our levels of MAO tend to increase as we grow
older. The observation that old women are generally more cautious than young
men is worthy of the findings of a research programme at ‘The
University of the Blindingly Obvious’, but the relationship to MAO
levels is of interest.
It has
been found that psychopathic criminals have particularly low levels of MAO so
are apparently willing to take much greater risks in society than
‘normal’ people. Bullfighters as a group were also found to have
low MAO levels – but there are some female matadors. It seems that if
we are born with low levels of MAO then we will be high risk-takers for the
rest of our lives, despite some moderation in older age. Perhaps, up to a
certain level, high risk-takers are also high achievers? Can one achieve
anything without some level of risk?
Would it assist the selectors of fighter
pilot trainees and future astronauts to measure MAO levels and reject those
with levels higher than some pre-determined datum? The possibilities could
expand to reject anyone applying for a job as a ‘Lollipop Lady’
at a school crossing unless she was over 65 and had an astronomical MAO level
– but then she would probably not allow any children to ever cross the
road just in case an unseen vehicle was lurking somewhere below the distant
horizon.
More seriously, it may be possible to
discover an effective way in which to permanently adjust the level of this
protein in mentally ill patients to return their MAO to ‘normal’
and so cure one aspect of their illness. It seems that currently available
MAO-inhibiting drugs are going out of fashion as anti-depressants. Perhaps boosting
MAO levels
would be more effective?
It seems apparent that we cannot produce a
zero-risk environment for human habitation. Even if we did, we couldn’t
exist there. It is also apparent that we, as individuals, cannot agree as to
what level of risk is ‘acceptable’ because what is acceptable to
me may seem nannyish to a younger man and, at the same time, foolhardy to an
old lady.
What has
this got to do with Flight Safety? I think it may go some way towards
explaining why some young macho male pilots are convinced that the REGULATORS
in CAA/FAA, (or wherever the local rule makers sit), are a lot of old women
who have forgotten all about real aviation while some of us older people
working in Flight Safety are equally convinced that many young pilots are
totally irresponsible and should be locked into the hangar with their
aircraft.
Both of these perceptions are (probably!)
wrong. It seems that they are at least partially chemically determined in our
brains and not much can be done to dramatically alter them at present.
‘Education’ and ‘persuasion’ can modify our perceptions
and understanding, but there will always be a gap in individual definitions
of ‘acceptable risk.’
If we can recognise and accept this gap in
perception then perhaps we can all concentrate on trying to keep flying
reasonably safe without aiming at an impossible target and one that may even
be undesirable.
I have no idea what my own MAO level is, and
have no desire to know. Despite being ancient, I still believe that a world
totally devoid of risk would be a totally boring place to inhabit.
Text and Photographs © 2008 Gremline & Hill House
Publications, unless otherwise stated.
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