IncIdents and accIdents - the Light Aircraft Association

Safety Spot
With Malcolm McBride
Airworthiness Engineer
incidents and
accidents
It turns out that we can all make mistakes, whether reporting on
previous incidents or making decisions in an emergency
elcome, as always, to this
midsummer issue of Safety
Spot; thanks for tuning-in, I
hope all’s well for you and those
around you. Now the weather’s
improved a little, all the various departments here
at LAA HQ are working at full power just to keep
pace with the incoming work which, apart from
the problem of finding time for a bit of personal
space, is just how I like it.
So far, as you probably know, this year’s
weather has been rather dominated by the
southerly course of the jet stream and, at least
here in the south of England, the weather’s
been very changeable… I’ve hardly had
the sails up on my old yacht, Vita Nova, this
year as the wind’s either been too strong or,
you guessed it, not registering at all on the
anemometer. I’m writing this issue of Safety
Spot over the May bank holiday weekend,
which is a bit annoying as I had originally
W
planned to sail off for a few days; just for a
change, there’s a steady 15kt south-westerly
blowing in the Solent (thanks to Bramblemet!),
just right for a trip over to Cowes… but then,
when you’ve gotta work, you’ve gotta work! In
any event, tomorrow’s forecast is rain.
Let’s start with a correction to the article about
the Luscombe that suffered an ASI failure on
take-off and subsequently ran into an obstacle
after the take–off was aborted. You will recall,
if you’re a regular reader of Safety Spot that,
in the April issue, I used this ASI failure to chat
about the importance of maintaining a certain
‘discipline’, especially with regard to ongoing
maintenance work, within the group-owned
aircraft world. I was impressed, if you recall, by
the way that this little group of five managed
their affairs; perhaps it would be better if I let the
group’s Technical Manager, Duncan Campbell,
explain what’s worrying him about the article.
His letter starts by reminding me that the
group had been invited to visit the RAF base
at Odiham, mostly to discuss the best way of
avoiding any incidents with the Chinooks that
operate from there.
Thank you for your coverage about our
Luscombe, G-AGMI, in Safety Spot in April’s
issue of Light Aviation. We all thought it
very balanced and well-crafted. We had a
successful visit to Odiham and, when the RAF
have confirmed the measures we agreed,
I’ll forward a brief report and photo(s) as
discussed. When we visited, there were very
few Chinooks in residence and, as they were
deployed to Nepal shortly after, I think we’ll
have a little wait before we hear from them.
My purpose in writing now is because the
article contained one small error in identifying
me as the pilot. I was actually P2, subject to
the full experience but not PiC. It naturally
caused my sympathetic group colleagues,
including the P1, some mirth and I thought
“ To date
ACF-50’s
chemistry has
not been found
to degrade or
embrittle any type
of aerospace
composite or plastic
component”
I featured this picture showing the remains of an electrical connector, which started its life
being attached to a rear fuselage mounted remote compass in an RV-6, in the May issue
of Safety Spot. We were worried that the bits and pieces could jam the elevator controls.
The slight suggestion, made in the caption to the photo, that the corrosion protector AC-50
was involved, raised the eyebrows of the boss of the company that makes this magical
substance… unzipping plastic’s molecular structure isn’t one of its properties in his view…
see the very nice letter in the accompanying text. (Photo: Tim Gibbs)
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(Above) Legend has it that Homer Kolb, when he was a lad, reasoned that, “If you could build a silo on a farm as high as 70ft without
permission, then that airspace up to that height must belong to the farmer.” That boyish thought set him on his way to building his first
ultralight aircraft, the Kolb Flyer which first flew in the early 1970s. Looking at the sports aviation marketplace now, Homer Kolb should
surely rank as one of the great innovators of our age. This picture, of a rather more recent example of this, for its day, very advanced
ultralight, reminds me a lot of one of the first UK microlights that I got my hands on, Steve Hunt’s Pathfinder (the Mk. 1!); that very early
single-seat full three-axis microlight flew like a dream as I remember. I’ve personally never flown a Kolb, but the Twinstar Mk. III, has a bit of a
reputation as a rather poor performer and doesn’t enjoy particularly good handling. (Photo: LAA Library)
it not worth raising when the magazine was
published. However, I am now running into
other flying colleagues who are asking me why
I had misled them! Like my group colleagues,
I take the view that what happened to my P1
colleague on that occasion could so easily
have happened to me, and the outcome may
well have been the same, but putting people
right is becoming a little tiresome. I wonder if
you could possibly acknowledge that the pilot
was incorrectly identified in the article in a
future issue of the magazine.
Thank you Duncan, I hate to think that an
error on my part has caused dissent amongst
your mates and am glad to be able to correct
the mistake… Honour restored and we’re
looking forward to your promised article about
your group’s visit to Odiham with regards to
the airspace issues around your strip. Having
spent some time flying in Nepal, I feel a certain
attachment to the people there and watched
the TV in horror as the disaster unfolded;
well done to the UK Government for acting
quickly with some airborne assistance. By
coincidence, I heard on the radio yesterday
that there had been an earthquake in Kent
the previous evening but, apart from knocking
over a few bins, the 4.2 (Richter scale) event
didn’t cause any injuries… just goes to show
you though, you never know where the next
problem’s going to come from.
You will also, I hope, remember the picture
of a failed electrical connector to the tail
mounted AFS magnetometer, sent in by RV-6
owner Tim Gibbs. The picture was featured in
last month’s mag. He was mystified why the
plastic connector had failed and suggested
that the commonly used anti-corrosion spray
ACF-50 might have affected the plastic in
some unusual way. I featured the picture to
remind owners to check things carefully, even if
they’re hidden away at the back of the airframe
- in other words ‘get the panels off during a
maintenance check, especially at an annual. In
the failed connector’s case we were especially
worried about the debris falling into the elevator
control mechanism and causing a jam.
Well, Brian Hope, our Editor, sent me an
(Left) Here’s Alex’s sketch of the accident site
near Otherton airfield. Alex and a pal had
planned to go on a cross-country flight in
this Kolb to the Long Mynd but, shortly after
take-off, he became aware that the elevator
control had jammed. Fortunately, the aircraft
was in a reasonably stable flying attitude,
although the aircraft was nose down and
steadily descending. However hard he tried,
he couldn’t get the stick back to pull the
nose of his aircraft ‘up’. Alex, thinking very
quickly indeed as you will imagine, elected to
land as close as possible to straight ahead,
using only the throttle, ailerons and rudder to
maintain control. (Diagram: Alex Crowley)
email he had received from Mark Pearson, the
Managing Director of Lear Chemical Research
Corp (www.learchem.com) that makes ACF-50
and I thought you might like to read it.
Let me start by saying I think you and
your staff do a wonderful job presenting a
very ‘reader friendly’, informative magazine
that is full of useful bits germane to the LAA
readership. While we don’t see them here in
Canada, I have had the pleasure of reading
several issues during my travels to the UK.
It was recently brought to my attention that
the May issue contained a reference to our
anti corrosion product ACF-50. This was on
page 52 of the article Safety Spot. I would like
to address the interesting comment made in
regards to ACF-50.
The picture shown is of a shattered plastic D
connector with the supposition being made that
perhaps the vapour from an ACF-50 treatment
reacted with the plastic material, causing it to
become brittle and disintegrate. To educate
your readership, ACF-50 was first introduced
to the aerospace industry in 1985. During this
30-year period ACF-50 has had both direct
and indirect contact with all types of aerospace
metals, composites and plastics, including
those found in some connectors. ACF-50 has
been tested to aerospace specifications which
specifically evaluate the product’s compatibility
with plastic materials. To date ACF-50’s
chemistry has not been found to degrade or
embrittle any type of aerospace composite or
plastic component.
Having said that there are a variety of
aerospace and automotive grade electrical
contact cleaners that if used on ‘noncompatible’ plastic materials will – almost on
contact – cause the embrittlement experienced
by the RV owner.
We are not sure what caused this connector
to shatter but can assure your readership that
ACF-50 was not the culprit .
I think that Mark’s letter says it all, certainly I
haven’t heard that ACF-50 does anything else
but protect materials against corrosion… a job
it seems to do very well indeed. Thanks Mark
for taking the trouble to write and I’m glad you
enjoy Safety Spot.
So, what’s happening in our fleet? Well, I’ve
just collated the reportable incidents and
accidents for the first trimester, that’s January
through April 2015, and we’re just a tiny bit up
on the annual average. Last year we recorded
63 incidents so, without trying to be too clever
about it, by now we would expect there to be
21 reports - I’ve actually recorded 24. The
interesting thing, and the reason for me giving
you these numbers, is the huge hump in the
graph describing Loss of Control during takeoff or landing. I alluded to this being likely at ›
the beginning of the year and urged members
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Because the pilot didn’t think that he had any pitch control he found himself unable to
accurately control the glide path of his machine and, after stalling during the last few
moments of the difficult approach, the port undercarriage assembly struck a fence
post; effectively destroying it. The aircraft ‘belly-landed’, slewing round to port after
touchdown. (Photo: Otherton Crew)
to take a check-ride if it had been a while
since they (you!) had last flown. If you’re not
very current you’ll probably get away with a
flight if everything goes well and there are
no problems. The story is very likely going to
be different if you get hit by that gust of wind
with your name on it or, as in the case of the
two incidents I’m going to discuss later in this
issue, you get a technical failure of some kind.
Of the 24 incidents so far recorded, 16 relate
to loss of control either on take-off or landing,
and two relate to loss of control during an
approach, so losing control of the aircraft
during the busy section of a flight accounted
for 75% of all the incidents. From our 24, only
six have significant technical content and four
of these incidents relate to accidents after an
engine failure, three Rotax two-stokes and one
Jabiru 3300… the Jabiru failure occurring,
incidentally and sadly, on its first flight. See
next month for the very interesting issues
connected with this incident.
So, most of our aircraft get broken during
take-off or landing. “OK,” I can almost hear you
thinking, “Tell me something I don’t know!”
There are two particular incidents with
significant technical issues, and some
operational points, that are worth exploring.
Kolb Twinstar Mk. III – In-Flight
Elevator Control Failure
With the hammock-type seat-back removed, this picture shows the fairly complex
tubular structure involved in connecting the front of the cabin to the rear fuselage tube.
Much of the tubing relating to undercarriage support was bent, but the damage was
limited to the undercarriage fixings. Note the push/pull elevator drive rod connecting the
belcrank to a centre-mounted control stick. (Photo: Malcolm McBride)
A possible reason for this control jam was that both the pilot
and the passenger flew with their coats unzipped; it’s very
possible that the wallet and big bunch of keys may have been
of a sufficient weight to alter the position of the drive cable’s
turnbuckle (relative to the aircraft’s structure) to cause a
temporary jam. (Photo: Malcolm McBride)
As I hope that you will recognise, I do try quite
hard to create a theme within Safety Spot; this
month, two recent accidents are so similar
that the tune to be played and, perhaps, the
lessons learnt within, are fairly obvious. Both
accidents led to the aircraft being written-off
but, very happily, neither caused any injury to
the occupants. Another important, and rather
unusual congruence, is that both the pilot/
owners willingly agreed to me chatting generally
about the causes even though a different
decision by the pilot during a difficult situation
may have resulted in a better outcome.
We’ve got 38 Kolb Twinstar aircraft on our
books, although at the time of writing we only
have 13 aircraft in-Permit and still flying - well,
actually 12 aircraft still flying if you remove
this particular machine from our list, which I’ll
do in a minute! That’s not the best of ratios,
although in fairness, the Kolb Twinstar was
›
a microlight aircraft of its time and, whilst it
When we looked more closely at this point in the elevator control
circuit, we could very easily simulate what might have happened
in-flight: whilst it was possible to simulate a jam on the ground,
even a small movement of the stick ‘tripped’ the temporary ‘lock’
allowing the system to become free again.
(Photo: Malcolm McBride)
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The Kolb Twinstar, as a type, has a
checkered safety record and one aspect
that is very worrisome is the lack of
protection to the pilot in the event of a
heavy landing. Following some serious
back injuries sustained during accidents
in the early 1990s, a Mandatory Permit
Directive (MPD) was raised by the UK CAA
to require a modification strengthening
the seat-pan of all UK Twinstars This
picture shows the seating arrangement
found on the incident aircraft and, whilst
some protection was afforded by the seat
cushion, it wasn’t modified in accordance
with the MPD. It has to be said that the
crew of this aircraft were lucky not to
sustain a serious injury in this accident
as it did involve an undercarriage failure.
(Photo: Alex Crowley)
Mandatory Permit Directives are, in
the Permit to Fly world, equivalent
to Airworthiness Directives in the
Certificate of Airworthiness world;
they’re ‘Directives’ and, unlike Service
Bulletins or Letters, they contain
‘must do’ things. Until 2011, the CAA
published a compendium of all UK
MPDs (CAP 661), this document,
frozen in 2011, is still available from
the CAA’s website (Type: CAA CAP
661 into your search engine) but later
MPDs are now only posted online.
Either way, if you’re conducting
an annual maintenance review on
an LAA aircraft (Part of the Permit
renewal process), it’s essential that
all the required MPDs are signed
off in the log-book (and, of course,
accomplished on the aircraft!).
The above picture shows the MPD
relating to the fitment of the seat
pan and the drawing of the seat
protection scheme that’s needed.
(Photo: UK CAA/LAA Library)
Further evidence to support the theory that the elevator jam
was caused by a turnbuckle impinging itself on the edge of the
fuselage’s rear tube can be seen in this photograph; note the
witness mark on the inside face of the tube. The insulating foam,
incidentally, was fitted to try to stop an ‘annoying’ rattle made by
the cables in normal flight. (Photo: Malcolm McBride)
This picture shows a close-up of the rod-end bearing used
to connect the elevator push/pull rod to the belcrank; aeroengineers will normally always require this sort of critical control
joint to be made failsafe (in the event of a bearing failure) by
fitting a penny washer under the head of the attaching bolt; with
a washer in place the connection will remain functional even
if the bearing falls to bits… comments about the quality of the
lock-wiring of the turnbuckle were noted by the author when
he showed this picture to the Chief Engineer but, it’s artistically
creative ‘unconventional’ appearance didn’t mean it wasn’t
effective… just rather difficult to recreate!
(Photo: Malcolm McBride)
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did look quite good, it didn’t have a reputation
of being a good performer. I do remember
one very experienced test pilot calling me one
afternoon here at LAA HQ exclaiming over the
telephone, “I can’t sign this off, it’s very slow
and doesn’t appear to be handling correctly.”
Worried that there may be something
critically wrong with this particular example,
I asked an experienced Kolb man to fly the
aircraft on test, issuing a special Permit Flight
Release Certificate to cover the flight with my
personal warning, “For goodness sake be
careful.” After a couple of weeks waiting for
some appropriate weather the new test pilot
emailed me stating that, ‘Yes, its handling is
pretty unusual, but very normal for type: and
there’s nothing wrong with performance… at
least for the type.’ There’s no doubt though, if
it’s cheap airtime you’re looking for, it would be
difficult to beat this generation of machine for
price, but don’t expect Spitfire handling. I must
sample one myself sometime.
Anyway, very belatedly, because of all sorts
of administrative hiccups, we only found out
that there had been a fairly serious incident
involving a Kolb Twinstar Mk. III about three
weeks after the occurrence. Fortunately, we
heard about it just before disposal of the
airframe by the rather expeditious insurance
company, as the machine had been writtenoff. I met the owner of the machine, LAA’er
Alex Crowley, at Otherton on the day that the
pilot and previous owner of the Kolb had just
collected his replacement, a fabulous Rans S6
ESA, bought with the settlement.
Alex has about 75 P1 hours under his
belt out of a total of about 150 flying hours;
originally he trained on a flexwing, only recently
converting to three-axis types. In fact, he had
only accumulated four hours on the Kolb, all
P1, so I don’t think that Alex would mind me
saying that he was rather learning ‘on-the-job’
with this new type! I was amused by one of
his comments, made whilst Andy Draper and
I looked round the machine. I asked how she
flew. “Well” Alex replied, “Everything seems to
happen at 60 mph!”
“There can be little
worse for a pilot
than to suffer a loss
of control authority,
especially at such
a low height; it’s a
situation that, in very
real terms, could be
described as a life
or death moment”
Here’s what happened in Alex’s own words.
The intention was to fly out to the Long
Mynd, accompanied by two other aircraft.
A full walk-round inspection was carried out
prior to entering the cockpit. After start-up I
taxied to the hold of Runway 25 (The wind
was roughly westerly, at or about five knots)
where I performed my pre-take-off checks.
Inclusive in the checks was a control check
which indicated full and free movement. As
there were two ‘POB’, I selected the rearward
trim (It is likely that the aircraft was close to
the maximum weight allowed which is 390kg)
and the first stage of flap for take-off and the
ground roll commenced. All instruments were
within limits and the airspeed indicator was
‘alive’. The aircraft climbed away at 60mph
indicated, as usual. Upon reaching 200ft the
flap was retracted and the climb continued. A
shallow left turn was initiated at around 450ft
to conform to the circuit procedure and remain
clear of the M6 motorway.
At this point severe restriction on the control
column was felt. The aircraft then began to
descend but the elevator control was extremely
hard and the descent could not be arrested
despite the application of full power. Given
the rate of descent I was confident I would not
make it back to the field and so I decreased
power to decrease the rate of descent and
initiated a forced landing. The only field I
considered suitable was a small paddock with
grazing livestock. Conscious of how short the
field was, with little control authority, I aimed at
the edge of the field. Upon passing 50ft I made
a Mayday call on the local frequency which
alerted my fellow pilots. As I came into the field
my left wheel struck a wooden post, destroying
the wheel and wing strut.
There can be little worse for a pilot than to
suffer a loss of control authority, especially at
such a low height; it’s a situation that, in very
real terms, could be described as a life or
death moment. Alex, when confronted with
an elevator jam, would have known that he
needed to act quickly if he and his passenger
were going to survive. I have little doubt that
his ‘fight or flight’ response system would have
kicked-in and the decision to ‘get back onto
the ground quickly’ was made almost in his
subconscious. If you’ve read the above part of
Alex’s report carefully you may have noticed
a couple of questionable actions. The first
question might be why Alex reduced power to
reduce his rate of descent? Well, as you can
see from the attached pictures, there is quite
a power related pitching moment on the Kolb
because of the position of the engine. This
gives an unusual feel to pilots more used to
the aircraft nosing up with an application of
power; with aircraft like the Kolb, an application
of power pushes the nose of the aircraft down.
So, Alex was clearly thinking about improving
his chances of survival.
The problem with reducing power, especially
on a draggy aircraft like this, is that in reality,
reducing the nose-down pitch angle won’t
necessarily reduce the rate of descent perhaps, and as it turned out, the opposite
I fell in love with the Aero-Designs Pulsar as soon as I saw a picture of the first prototype back in the 1980s… so much so in fact that I
went to the States to visit the aircraft’s designer, Mark Brown, and bought a kit after half-an-hour’s flying in his prototype! The original
version was powered by the Rotax 582 two-stroke engine and, primarily because of the machines very lightweight, handled beautifully.
This example shows the later model which was fitted with the 912UL engine. Sadly, for all sorts of reasons, this particular type never
really got off the starting blocks here in the UK; the clearing banks withdrawing support from most of the UK’s embryonic sport plane
businesses in the early 90’s didn’t help much! (Photo: LAA Library)
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would be true. An eyewitness reported that the
aircraft ‘became quite slow on the approach
and stalled just as it was going over the field’s
boundary’.
So this pitch ‘issue’ caused a bit of a
balancing act which the pilot very nearly got
completely away with… as it was, it was a
successful emergency landing because both
occupants walked away without injury, so very
well done to Alex. My critical comment here is
that you can’t beat airspeed as a currency in a
situation where you’re forced into a field… it’s
your cash in the hand. Height, if you’ve got any,
can be thought of as ‘money in the bank’, and
below 500ft you’re not very solvent unless you
have a sensible airspeed!
Another critique is that 50ft on an approach,
under any circumstances, is no time for radio
calls, even Maydays.
I’ve covered what the most likely explanation
for the control restriction was in the
accompanying pictures. The aircraft itself
looked to be in fair condition but it was clear
that it hadn’t been maintained very well through
its life; both elevator drive cables were far too
slack to be effective, an issue noted previously
because somebody had tried to reduce their
rattling by covering them with water pipe
insulation and this alone probably led, as you
can see for yourself, to the temporary jam.
Also, at the last annual inspection, neither
the previous inspector nor the new owner
had taken a look through the aircraft’s Type
Acceptance Data Sheet (TADS). Had they
have done so they would have noted the
mandatory requirement to fit a strengthened
seat pan and a special, high density foam
seat cushion.
That aside, if you ever get into an awful
position where you end up with an in-flight
emergency, try to resist the ‘blinkering’ effect
caused by the ‘fight or flight’ response; in any
situation there will be a number of options.
OK, you will inevitably act quickly to save
the day but, if you’ve got time, reassess the
situation. In this case, if Alex had operated the
elevator control a few times or, perhaps, just
looked at the control mechanism, he would
have realised that the control restriction was
only a temporary one; and, perhaps, if the
crew had simply just done up their coats, the
emergency situation would have passed as
just another crew-room story.
This picture looks down and aft onto the Rotax 912 UL engine as fitted to the Pulsar
that suffered an in-flight throttle control failure. Notice that the port carburettor air filter
is a different shape to the starboard suggesting a considerable movement of the engine
during the impact. The important thing to notice is that the modified throttle system
includes two very short Bowden cables, one to each carburettor. Because these cables
are very short, any movement of the engine transmitted drive to the throttle cable itself,
often asymmetrically, which showed itself (in hindsight) through irregular bouts of
rough running.
This is a good example of why it is essential to get a modification checked-out and
approved by a qualified organisation. Certainly this new throttle system, featuring left
and right throttle levers, is a more conventional system than the one originally approved
on initial build (basically a single throttle lever with the cable passing through a one
into two splitter box). The new system has the advantage of the variable throttle friction
device on the P1 side, necessary with a carburettor designed to default to full power if
its control connection is lost. However, the design features a number of gotchas which
would have been spotted during an approval procedure. (Photo: Keith Rigby)
Pulsar XP – In-Flight Throttle
Failure
In this next example, a similarly experienced
chap had another type of control issue and,
even though his method of dealing with the
emergency was, and I hope he’ll forgive me for
saying this, a bit daft, he stuck with his plan to
the bitter end.
I received a little note from Fiona, one of our
fabulous engineering admin support staff.
Eyebrows oscillating hopefully I read, ‘Keith
Rigby, the owner of a Pulsar phoned… he
wants to report an incident’.
Keith answered his phone after a couple of
rings and I said, “Hello Keith, it’s Malcolm. You
OK?”
“Not really”, he replied. “I don’t have an
aeroplane any more.”
After a bit of a chat I was happy to work
out that although the final moments of Keith’s
Pulsar were pretty dramatic, he walked away
from the crash without a scratch.
Let’s start from the beginning, well perhaps ›
not the very beginning; I’ve only got enough
The picture on the top shows how the throttle should look when assembled correctly
and the one on the bottom shows how it was found by LAA Inspector Alex Hastings,
after he visited the aircraft to try to establish for us what had gone wrong with the
system to cause it to fail. Because the nut securing the throttle lever to the angle bracket
attachment wasn’t sufficiently locked in place it had come undone and was rattling
up and down the stainless steel shaft behind the instrument panel to which it was
affixed… every now and again the nut would jam under the shaft stopping the throttle
from closing fully. The silly thing (again, with the benefit of hindsight) is that this ‘jam’
had happened before to the pilot although on previous failures, after a bit of ‘wiggling’,
the jam had cleared. He’s kicking himself now of course because he didn’t check this
annoying problem out at the time. (Photos: Alex Hastings)
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space for a few hundred more words! Keith,
like many of the LAA’s flying membership,
came to flying as soon as the realities of his
life allowed, in Keith’s case his early 70s. Not
that, perhaps like many, he hadn’t maintained
a ‘very close interest’ in all matters aviation;
it’s just that the opportunity to actually learn to
fly didn’t happen until he was, well, 72. Keith
started to learn to fly at Cumbernauld Airport
in Scotland and, after 60 or so hours training
(and practicing), gained his PPL… not bad
at all for a septuagenarian, or anybody else
these days for that matter. Keith learnt to fly
on the Rotax 912-powered Diamond Katana,
the Canadian-built but Austrian-designed
composite two-seater. I mention this because
he did know how to handle, and what to expect
from, the Rotax power unit and was quite used
to handling fairly ‘slippery’ aircraft. So, about
a year ago, he bought a Pulsar XP, an almost
natural choice.
The actual machine that Keith bought
had clearly been looked after very well and
the quality of engineering was, in Keith’s
opinion, completed to a very high standard.
In retrospect though, a lot of the changes
made hadn’t been through a proper design
evaluation. Our records, for example, show
that we did know about an oil cooler mod
and the (nearly) full airways radio/nav kit on
board was fully signed-out. However, we didn’t
know about the electrically operated flaps, the
permanently coupled wing leveller (Auto Pilot)
or, pertinent to this accident, the change from
the standard throttle set-up offered as part of
the original kit. This aircraft, incidentally, had
only completed just over 100 hours since its
first flight in 2005.
Keith wasn’t happy with the engine on his
Pulsar, the power unit was suffering irregular
bouts of rough running and, having some
experience with the Rotax fuel set-up, he
assumed that it was because the carburettors
were unbalanced. He decided, back in April,
to take the machine up to see whether the
problem occurred at any particular rpm. The
aircraft is based at Fife Aerodrome, which
enjoys a 700m tarmac strip (which I can testify
as being in excellent condition) although it
isn’t licensed, so emergency services are only
offered on a volunteer basis.
Keith’s take-off was very normal and he
climbed up into the circuit planning to carry out
a touch-and-go. On the downwind he tried to
“I have to say, after
talking to the witness
and Keith himself, I
think that God must
have been watching
over him that day
as he walked away
from the wreckage
without a scratch”
reduce power but found himself unable to get
the power back much below 3,500rpm; this
meant that it was difficult to slow the machine
down. Despite this, Keith thought that the best
thing to do was to try to slow the aircraft down
by raising the nose above the horizon and, fully
aware that he would then be flying way behind
the drag curve for the machine, carry out
an approach ‘hanging on the prop’. The first
attempt, using this method of speed control,
went awry and he found himself “in the right
place – but far too fast to make a landing.”
The second attempt, using the same method,
also wasn’t successful but did attract the
attention of a local flying instructor who later
commented, “I first saw the aircraft approaching
the runway at about 45°, it had a very high nose
angle, far higher than looked safe, and the
wings were rocking from side to side. I had a
student with me and I explained that we were
about to witness a crash.” As it turned out,
Keith realised that things weren’t going well and
aborted this landing attempt too.
Third go! Well, this was pretty much like
the first two although he found himself in the
correct position over the threshold, “a little slow
but too high for a flare.” The observing flying
instructor, now positioned in the aerodrome fire
engine, takes up the story. “It was clear that this
pilot was in trouble, the aircraft was flying at, or
at least just above, the stall all the way down
the approach. I’m not sure what sort of height
he was when he reached the runway threshold,
perhaps 15 to 20ft, although he was far too high
to flare. Then, quite unexpectedly, the engine
went to full power (the usual Rotax default to full
power problem), the nose rose still higher, the
aircraft stalled and entered a spin with the left
wing hitting the ground.”
I have to say, after talking to the witness and
Keith himself, I think that God must have been
watching over him that day as he walked away
from the wreckage without a scratch. Keith
thinks that his other hobby, ice dancing, had
prepared him well for the impact; apparently he’s
spent quite some time on his bottom pursuing
whatever perfection ice dancers pursue!
So, space is running out, what’s to learn.
Well, in both the instances we’ve discussed
in Safety Spot this issue, the pilots encountered
an in-flight emergency. The Kolb pilot thought
that his controls were jammed and reacted
accordingly but, after the initial ‘fight or flight’
response (Get Back On The Ground, And Fast)
had been made he didn’t check the pitch control
to see if the jam had cleared itself. In other
words, when the situation had stabilised itself, no
re-assessment was made. Same with the Pulsar
captain, although this chap had a lot more time
to reassess, he never put this on the agenda.
Actually, dragging an aircraft in over the
threshold ‘on the prop’ is a well-known, but
for experts only, method of carrying out a
very short landing; it’s not a sensible way of
controlling airspeed if you get a stuck throttle.
Two other options that Keith would have
considered are: 1) climb above the airfield
and, after letting everybody know what you’re
doing, switch the engine off and carry out a
dead stick landing. No big deal. And 2) come
in fast on the approach and switch the engine
off when you’re absolutely sure that you’ll get
in… if 700m isn’t enough fly to a bigger airport,
tell D&D what’s happening and they’ll assist you
with your best options.
The other lessons shared between the two
events include the consequences of when mods
that should have been done weren’t, and mods
that shouldn’t have been done were. That aside,
both pilots, one very young and one not so
young, were both new to our sport. When you,
with all your experience, see them struggling a
bit, don’t leave them to it; keeping people safe
when operating an aircraft is what the LAA is all
about. It’s an Association thing. Fair Winds. ■
LAA engineering charges – PLEASE NOTE NEW fees have applied since 1 april 2015
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Latest SPARS - No.16 February 2015
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54 LIGHT AVIATION | JUNE 2015
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