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.
a.. 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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