The investigation into the U.K. accident on January
18th is being led by the AAIB (Air Accident Investigation
Branch) of the DfT (Department for Transport) with the
co-operation and involvement of the BGA (British Gliding
Association). When the investigation is complete the report
will be published by the AAIB on their web-site at http://www.aaib.dft.gov.uk/bulletin/bulletin.htm , please note that these reports are listed under the month
of the report, not the month of the accident. I have only heard
conflicting rumours about this accident, I am being careful not to form an
opinion until the report is published.
The previous 5 Puchacz fatal accidents in the U.K.
were all investigated by the BGA (with the agreement of the
AAIB). Brief details are as follows:
U.K. FATAL ACCIDENTS TO PUCHACZ GLIDERS.
1990/08/04 114/90 South Wales G.C.,
Usk.
The purpose of the flight was instructor training,
the club Chief Flying Instructor was preparing an Assistant Category
Instructor for his Full Category Rating test. After an aerotow, a
deliberate spin was entered at 1,400-1,200ft. above the airfield.
There was no problem caused by any difficulty in recovering which was simply
started too low. A tape recorder was being carried, and this is
why these facts are known, the tape stopped within three seconds of recovery
being started. The CFI in the front seat was killed.
1991/07/28 111/91 Shalbourne Soaring
Society, Rivar Hill.
After a slow winch launch to about 1,000ft. the
glider started to spin with the wire still attached. It was the pupil's 25th
launch, so it is reasonable to suppose that the pupil was flying the launch;
the pupil had not received any spin training. After two turns to
the left the rotation stopped but it immediately span to the right, there is
uncertainty as to whether it had actually stopped spinning before
impact. The probable cause was considered to be "Pupil alarmed by
spin entry failed to recognise spin and in a state of panic overrode the
instructors attempts to push the stick forward and failed to hear any
instructions to relinquish the controls." I am quoting from an
interim report which I have, there is reference to witness statements which I
have not seen, I understand that before the instructor died he stated that he
could not regain control of the stick, I have heard stories that this theory
is supported by other evidence.
1993/08/13 132/93 Derby &
Lancashire G.C., Camphill.
This was an air experience flight, the pupil's
first flight. The glider was launched to between 1,000 and 1,200
ft. It was seen spinning at about 600 ft. at the start of the
downwind leg and crashed 300 ft. below the hilltop (i.e. below the
airfield height, in the valley). The spin had stopped but
there was insufficient height for recovery from the ensuing dive.
The glider crashed at a nose down angle of about 70 degrees killing both
crew. I have not seen the report but I have heard from someone who
was current at that club at the time that there was evidence of a struggle in
the cockpit, and that there may have been medical factors affecting the pupil
(who I understand had signed a medical form without declaring any
problem). In other words it appears likely that the pupil
held the stick back and the instructor could not take control until too late.
1995/05/05 82/95 Coventry G.C.
(now The Soaring Centre), Husbands Bosworth.
This was an air experience flight, the pupil's
first flight. The winch launch failed when the cable broke at
between 150 and 300 ft. The pilot recovered to normal gliding
attitude and then turned through 180 degrees. After a short run
downwind a further turn into wind was started. During this turn
the glider span and the pupil was killed.
2003/02/21 20/03 Derby & Lancs.,
Camphill.
This was a mid-air collision between the Puchacz
and a winch cable being used to launch another glider. The pupil
was on his second flight, he had previous paragliding experience.
The pupil was flying the glider as directed by the instructor when the cable
was hit at about 600 to 800ft. The glider being launched back
released but did not realise that anything untoward had happened.
"The instructor quickly regained control and realising that the winch cable
was still attached to the left wing and that the left wing was damaged, opened
the airbrakes to descend quickly and spiralled down over the airfield just
north of the winch. The instructor then straightened out from the
spiral descent when about 150-200ft. above the ground and attempted to land
the glider heading north, back towards the original launch point.
Quite soon after he had straightened out from the spiral descent the
instructor lost control of the glider and it hit the ground in a steep nose
down attitude, severely damaging the cockpit area." That was a
quote from the report which I have, it seems that the cable still attached to
the wing stopped the glider in mid-air. The pupil was killed.
2004/01/18 The Soaring Centre, Husbands Bosworth.
Two killed, AAIB ongoing field
investigation. The glider was certainly seen spinning, more than
that I do not know. I feel that speculation as to the probable
cause is pointless before the report is published.
SUMMARY.
One deliberate spin, advanced instructor training,
no recovery problem, recovery left too late.
Two inadvertent spins where the pupil held the
stick right back and the instructor could not take control until too late.
One spin off a low winch cable break circuit,
instructor flying.
One mid-air.
One spin, cause as yet unknown.
None of the accident reports suggest any problem
with the stall/spin recovery characteristics of the Puchacz.
I have not heard of any stall/spin recovery
problems in the U.K. with the Puchacz, such as delayed recovery.
There have of course been such reports from other countries.
THE BGA AND STALL/SPIN TRAINING.
So far as I know, there has only ever been one
fatality in the U.K. from a deliberate spin, 114/90 above.
There has been much controversy relating to the BGA
suggestion that some spin entries should be made at low altitude.
This idea is greeted with horror on the West side of the Atlantic, and it is
controversial in the U.K. as well. Yet so far as I know it has
never killed anyone. It may be worthwhile to consider why it is
done.
HISTORY RELATING TO STALL / SPIN TRAINING.
Some years ago those investigating accidents formed
the opinion that pilots who were perfectly capable of recovering from an
inadvertent stall/spin at altitude were failing to recover from a departure
from controlled flight at low height, in particular at heights where recovery
was possible provided immediate correct action was taken.
As a consequence of this, two changes were
introduced to the training of solo pilots, and to the coaching of
instructors. These were an introduction to the stall when effects
of controls are first taught, and showing a stall/spin at low altitude once
these had been learned in the upper air.
Full details of the current recommended methods are
to be found in the BGA Instructors’ Manual (1994), Second
edition (2003).
1. / A very gentle stall is
demonstrated and taught when the effect of the elevator is first taught, which
is the first lesson when teaching effects of controls. This is so
that the new pilot knows right from the beginning that in some circumstances
you can move the stick back and either nothing happens, or you get exactly the
opposite of what you expected.
2. / To quote from a long section in
the Manual (page 19-3), ADVICE TO INSTRUCTORS:
“In the initial stages of spin training, continuous
spins of two or three turns are mainly to allow the trainee time to study the
characteristics of the spin and give confidence that the recovery action from
a stabilised spin is effective. There is no requirement for these
spins to be noticeably close to the ground, so their training value is not
compromised if they are completed very high. The majority of spin
training will then involve brief spins of about half a turn with the primary
aim of recognising the circumstances in which a spin can occur, correctly
identifying the spin/spiral dive, and practising the correct recovery action.
“As this training progresses, it is necessary to
introduce brief spins where the ground is noticeably close. This
is to ensure that the trainee will take the correct recovery action even when
the nose is down and the ground approaching. A very experienced
instructor flying a docile two seater in ideal conditions may be prepared to
initiate a brief spin from 800 ft. A less docile two seater with a
less experienced instructor, or less than ideal conditions, should raise the
minimum height considerably.
“THE CRUCIAL ACTION is to move the stick forward to
unstall the glider EVEN though the nose is dropping or pointing steeply
downward. It is the inability of pilots to take this action when
the nose drops unexpectedly which results in stalling and spinning accidents.”
FAILURE TO HAND OVER CONTROL.
This may be a bigger problem than is generally
realised. You will note that two of the Puchacz fatals, both
double fatalities, were almost certainly due to this.
There have been other such accidents.
There was a fatal accident to a K13, where the
pupil held the stick forward and the instructor was unable to regain
control. I do not have the date or reference, I know the
instructor but have never talked of it with him.
There was a similar accident in the USA, which I
discovered by chance (I have not done any kind of search of the NTSB
records): 88.10.29 - LAX89LA027 - http://www.ntsb.gov/NTSB/brief.asp?ev_id=20001213X27100&key=1 Let L-13 Blanik – Flight controls restricted by passenger –
One killed.
There was a similar accident at the London Gliding
Club, Dunstable. I know the instructor (who was one of the
professionals) and first heard about the accident from him, he thought
he was about to die but they both got away with minor injuries.
29th April 1988, 43/88, brief narrative: “The visiting solo pilot was being
checked out to fly a club glider but his flying was of a poor standard and P1
arranged cable break practice. On the first at 500ft the stick was
violently pushed forward. On the second, at 50ft, P2 banged the
stick onto the back stop and P1 could not move it. The glider fell
to the ground after a hammer head stall.”
IS THE PUCHACZ DANGEROUS?
1./ You will not have spinning
accidents in a glider that will not spin. The K21 will certainly
spin if the C. of G. is far enough back, but as normally loaded it is very
unlikely to spin. The Puchacz will I understand spin at any legal
C. of G. position.
Can you teach a pupil properly in a glider that
will not spin? This is why some sites, e.g. Lasham, and Bristol
& Gloucester at Nympsfield still insist on using the K13, when they might
have been expected to "modernise" by using the K21.
But the Puchacz will not forgive poor handling, and
an inadvertent stall will almost certainly result in a sharp pitch down and a
spin entry.
A great many modern, single seat, types depart even
more sharply and with considerably less warning. It would be
interesting to look at the fatal and serious injury spin-ins in single seaters
and see what types were used in their training. It would be nice
to know if training in two seaters that spin readily does provide extra
protection against single seat spin accidents, or not?
Additionally there is a certain type of pilot,
including some instructors, who may be “spin happy” and spin more and lower
than they should, though I don’t know of any accidents in this category except
perhaps 1990/08/04 114/90 above.
2./ If the pupil holds the stick back
and prevents the instructor taking control perhaps you have less chance in the
Puchacz than in most gliders.
3./ Some gliders protect their pilots
in a crash better than others. For instance if you are going to
crash a standard class glider choose an ASW24 or ASW28, not an LS8.
I suspect the Puchacz is rather poor in this
respect, and not as good as an ASK21, K13 or DG500. I suspect that
my friend in the ASK21, 29th April 1988 43/88 above, would not have got away
so lightly in a Puchacz, it would have pitched down harder and given much less
protection.
DISCLAIMER.
Nothing I say is in any way official. I
am not, and never have been any part of the BGA hierarchy; I have never been
part of or associated with the Instructor or Safety committees or involved
with accident investigation. I have been in U.K. gliding for over
40 years, and instructing for about half of that; and I have been a member of
several clubs so I have quite a wide acquaintanceship.
