On Thu, 8 Jan 2004 10:57:33 -0800, "Marc Ramsey"
wrote:


"Chris Nicholas" wrote...
"The operators' attention is drawn to the following factors which may
cumulatively contribute to a hazardous situation:

(a) Low experience of glider and/or tug pilot
(b) Gliders fitted with C of G hook only
(c) Glider's C of G towards the aft limit
(d) Turbulent air in the take-off area
(e) Rough ground in the take-off area
(f) Significant cross-wind component."

snip...
Seems to me that if people want to go on risking lives in other
countries, feel free - and tell the tug pilots' families you don't mind
being sued, having read about and ignored the entire series of
recommendations that seem to have largely eliminated this type of
fatality where it was researched.

The length of this thread, and the bulk of the argument resulted from the
fact that some took one of the 6 points listed aboved (b) and made the
unequivocal statements to the effect that aerotowing with a CG hook was
dangerous and bordered on criminal. This is not, apparently, what the BGA
has said, it is simply the opinion of certain individuals.

I didn't notice anyone arguing that nose hooks aren't better for aerotowing,
the issue is whether CG hooks are sufficiently less safe than nose hooks
that we should flat out refuse to aerotow with them. For obvious reasons,
it is difficult to provide evidence based on actual accident data which
would justify the latter. We have, however, had at least 3 towplane upsets
here in the US that involved gliders with nosehooks, so eliminating CG hooks
most clearly will not eliminate towplane upsets and associated fatalities.

Here in the US, anyway, if we were to take a chunk of money to improve the
safety of aerotows, I'd say there is reasonable evidence that retrofitting a
bunch of gliders with nose hooks is not the most cost effective approach.
I' guess we would likely save a lot more tow (and glider) pilot lives, for
less money, if we (a) developed a safer alternative to the Schweizer tow
plane hook, (b) retrofitted swing open glider canopies with a spring loaded
positive latch, and (c) retrofitted gliders that have divebrakes that open
when unlocked, with a Piggot-style hook arrangement.

Marc


Spot on Marc.
a) Is already available.
b) Is problematical - there is a lot of friction in a Schempp canopy
latch which if the closing spring was powerful enough would likely
make the canopy difficult to open.
Whatever happened to pre takeoff checks?
c) Is a good idea and incredibly cheap to implement so worth doing
even if the benefit is slight.

It is the easiest thing in the world to spend someone else's money on
safety improvements. The aim must always be to spend it in the manner
where you get the most improvement for your dollar. Otherwise we are
open to uncontrolled cost increases for "improved safety" mostly based
on little more than conjecture.

Mike Borgelt