Harry I see that at page 3 of the latest Soaring Australia is an
article on Australian gliding accident and incident statistics going
back to 2004.
On 29/05/2010, at 10:47 , harry medlicott wrote:
Hi Dion,
Your well written comments are spot on. A pilot of marginal ability
is better off taking an aerotow or not flying at all .Proper
training and maintenance of skills is essential.
Can't get away from the accepted fact that every adverse situation
on a winch launch can either be avoided or handled which points to
pilot ability and inadequate training as causal factors.
The BGA analysis of accidents and their program "Safe Winch
Launching" appears to be reducing their accident rate, perhaps by
half, but early days yet.Their accident rate would be influenced by
- long winter break and lack of currency - generally much shorter
airfields than Australia, often surrounded by unfavourable terrain -
actual pilots may vary in personal skills betwen aerotow and
winching - winching mostly used for training and early solos.
Rather sad that we have to look overseas for statistics. Nothing
useful has been published on the relative accident rates of aerotow
and winching in Australia so far as I know. In fact nothing much has
been published about accident and incidents. Non judgemental and
unidentified reports as to airfields or personalities published in
SA , similar to that which appears in Sailplane and Gliding would
be a good start. Believe we all learn from such reports. The
thought goes through ones mind - musn't let that happen to me.
One small point in your notes. The Brits, and something I insisted
on myself when instructing, was that a hand must be actually on the
release in the early part of the launch. No time to grope for it
when things are going wrong. As in avoiding a cartwheel, often a
second is the difference between an incident and an accident. The
Brits counter the argument that having a hand on the release may
result its premature and unexpected operation by saying that by
their records there has never been an accident following an
unintended release. My glider has its release knob at the bottom of
the instrument panel just beside and beyond the control column,
awkward to find even when not under pressure. Have fitted an
extension consisting of a loop of 4mm poly rope and handle which
goes around the release knob and allows release to be held when
fully back in the seat When instructing at CCSC had a spare loop
handy for any pilot who could not comfortably reach the release
knob. Probably not kosher by GFA. Pretty unusual but I saw a wing
drop and start to catch the ground. The pilot saved the situation by
instantly releasing.
Dion, with your skills you would make, assumimg you are not already,
an excellent instructor,
Harry Medlicott
----- Original Message -----
From: Dion Weston
To: Discussion of issues relating to Soaring in Australia.
Sent: Saturday, May 29, 2010 9:20 AM
Subject: Re: [Aus-soaring] Winch Launch Technique
Agree with you Harry - the winch is much maligned - but the stats
Tim points to do seem pretty irrefutable - suggesting winching
requires a skill level above and beyond that needed for aero-tow and
that winch technique is generally a weakness in the training
curriculum. I'd also add lack of currency checks to the latter.
I learnt to fly on a high tensile single wire winch in the rough and
tumble and abrasive red dust of Bond Springs aerodrome, up on the
edge of the Tanami plateau north of Alice. In some ways the frequent
wire breaks there were a godsend. The assumption on launch was that
wire would break. Any launch completed without a break was a bonus.
I had a wire break at 200 feet on my second solo, a wire break at
400 feet on my third solo and, to top it off, a winch failure (ran
out of fuel) at 600 feet on my fifth solo. The latter was
particularly interesting as the power loss was gradual not
precipitative. The first two involved a straight in landing ahead
and the third a modified cct. for a mid down wind entry back onto
the strip.
My view - executed correctly there is no point in a winch launch
where in case of launch failure it is not possible to release,
recover and land back on the active strip.
This is definitely a learnt skill and one that does not
automatically stick with you if not practised.
Best technique hints that made the whole arrangement work like a
dream every time:
- Centre stick pre-roll for best assessment of a two point pitch
attitude.
- Do not operate the stick in the early stages of the ground roll
other than to adjust yaw balance and confirm or establish correct
two point fore/aft attitude.
- When the aircraft has sufficient speed it will decide lift off.
- Positively identify the ASI moving upwards through 40Kts.
- Pull back on the stick about a centimetre or at max two finger
widths.
- All things above being in order, without further stick input the
aircraft will rotate itself to best (i.e. safest) climb attitude and
stick there with minimal overshoot.
- As soon as the climb attitude is established check left and right
for yaw attitude, begin to assess wind drift correction and, just to
be completely anal about it, deliberately acknowledge that the
airbrakes are fully locked away.
- Feel for and positively identify you have clear access to the
yellow release bung.
The rest of the launch as per normal re: pitch adjustment for
airspeed, adjustment for crosswind and maintaining situational
awareness.
This arrangement may not achieve the absolute possible max launch
height possible but it does increase the probability you will remain
mid-envelope throughout the launch - and that means max options on
launch failure.
Dion Weston
On 28/05/2010, at 20:30 , harry medlicott wrote:
Hi All,
My own experiences re winch launching and safety be of interest. I
learnt to fly using the winch at Warkworth. To the best of my
knowledge never an accident using the winch in the years they were
using one. Helped establish the Central Coast Gliding Club and was
a busy instructor there. They were doing 3,000 winch launches per
year. In the 15 years I was there and so far as I know after that
no accidents - a time span of nearly 30 years. Moved to LKSC nearly
15 years ago. The club and its precursors have been using a winch,
very extensively for mid week training for some time, again no
winch launching accidents to my knowledge over 40 years which goes
back well before I started gliding so cannot be certain.
As against that there have been 4 aerotow accidents involving 5
deaths where I have personally known the people involved. in two
cases a midair during the launch, another was a tug wing structural
failure and in another the tug pilot dropped the glider just before
a fence.
Have been dedicated to safety for all my gliding career and
carefully studied all aspects.The British, who perform about
300,000 winch launches per year and have accurate records going
back 35 years have carefully analysed all accidents and have
identified causal factors. We in Australia can learn from their
conclusions and reccomendations. As an example in Great Britain,
there is an accident involving injury when a glider cartwheels due
to wing drop and catching the ground about once every 400,000
launches, Once a cartwheel starts it is unrecoverable and pilot
injury almost certrain. The conclusion and advice. Keep a hand on
the release during the early part of the launch - no time to grab
it if things start to go wrong. If you cannot keep the wings level
and a wing is about to touch the ground, release immediately. Might
be an inconvenience and a 99% chance you would get the wing up but
if all pilots released as advocated then that 1 in 400,000
occurence would not occur. The same applies to all other possible
reasons for an accident. At Lake Keepit usingDyneema rope and a
world class winch the chance of a rope break/ power failure is
remote but can still happen. Adequate training is essential.
Maintaining LKSCs perfect winch safety record is my priority..
The undisputed fact is that a winch pilot can either avoid or
safely handle every conceivable situation which might occur on a
winch launch. Even if a winch driver deliberately tried to cause an
accident, the pilot can control the situation. Believe that if
something goes wrong it is an instruction failure rather than pilot
error.
Safe flying,
Harry Medlicott
Harry
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