CG hook on aero tows??

In article , Andy
Durbin writes

I have flown the last 15 or so years with aerotow on a cg hook. My new
ASW-28 has forward and CG hooks but I have never used the forward
hook.

First of all, if the manual says to not use the C.G. hook
for aerotow, I personally wouldn't try it, even once.
But that's just me.

Next, as a tow pilot, if I ever towed someone and found out
they used a CG hook not allowed by POH, I'd
have a lengthy discussion with the pilot. I'd explain why
I'm not interested in doing abnormal procedures without
being informed before the flight. I don't believe
I always must do everything recommended, but if I
decide not to, I MUST acknowledge that I am now a
test pilot, and have perhaps voided any insurance. I also
need to get the approval of anyone else put at greater risk
(a second pilot, the tug driver, etc.).

We had this happen when flying the Blanik L-13 without the
canopy. There was quite a bit of discussion and agreement
from all parties before doing this. In the end everything
worked out fine, but more importantly, everyone had input
and was comfortable that precautions and research had been
done. And boy was it FUN!

I would think glider CG might be an issue here.
In the past 15 years, you've flown using the CG hook of
a glider that has a certain CG and a certain, perhaps
fairly forward, loading. A new glider with a different
placement of the CG hook relative to the CG may
be a completely different ride. If you do try it, keep
meticulous records, and send a report to the manufacturer.
I bet they'd like to know, since maybe their test pilot
was too chicken to do it himself.

If you do decide to use the CG hook for an aerotow,
despite the voices here and the POH, at the very least
get the cooperation of the tow pilot, since it isn't just
you taking a risk. And if you can't find a towpilot to
agree, maybe that's a sign...

Another thought...is it possible to rig a towline in such a way
that it has TWO rings? So that one could release the nose
ring and then be on the belly ring? Could one then
launch (the super dangerous part) using the nose ring and
then release this and experiment using the belly ring up at
high altitude?

Hmmm...I guess not since they both release using the same
mechanism...but otherwise this seems to be a better way
to experiment than taking off on the CG hook.
I'd suspect that a factory test pilot who wanted to test both
hooks for aerotow might try something like this...with
two individual release knobs perhaps...

Of course all of this begs the question: if the glider
HAS a nose hook for aerotow, why not just use it?
But that certainly wouldn't encourage a nice armchair
discussion, right?

On 6 Jan 2004 12:41:34 -0700, (Mark James Boyd)
wrote:


First of all, if the manual says to not use the C.G. hook
for aerotow, I personally wouldn't try it, even once.
But that's just me.

In the case of the 28 it's not a question of danger: Hundreds of 24's
(which has only a different wing, but identical fuselage, CG and tail)
are flying with CG hook only.

But what do you do with a glider like our ASW-27?
If only a CG hook is installed (yes, there are at least 150 27's
flying like this), it's fully certified for aerotow on the CG hook.
Since the new rules came out, all new 27's have a nose hook installed
and therefore this one MUST be used for aerotow.

Does the installed nose hook suddenly make the aerotow on the CG hook
dangerous?

(Consequence: Many owners of new 27's removed the nose hook).

The same goes for nearly all current gliders that were previously
built with only a CG hook and which are currently produced with a nose
hook.

A new glider with a different
placement of the CG hook relative to the CG may
be a completely different ride. If you do try it, keep
meticulous records, and send a report to the manufacturer.
I bet they'd like to know, since maybe their test pilot
was too chicken to do it himself.

If a CG hook is certified, the manufacturer has tested it for all
possible CG's.

Another thought...is it possible to rig a towline in such a way
that it has TWO rings? So that one could release the nose
ring and then be on the belly ring? Could one then
launch (the super dangerous part) using the nose ring and
then release this and experiment using the belly ring up at
high altitude?

Why would anyone do that?
The disadvantages of a nose hook is that it oftern creates significant
noise, draft, a little drag, costs money to build and to maintain.
Inflight it's nice to have.


Of course all of this begs the question: if the glider
HAS a nose hook for aerotow, why not just use it?

See above..
I admit that I've covered the nose hook with tape to get rid of the
noise and the draft when I was flying on very cold days - Schleicher
screwed up the design in my opinion.

An aerotow on the nose hook is probably less prone to pull the
towplane's tail up - but so far I have not seen one single accident
(!) statistic that could prove this point. I guess that by today
enough gliders with a nose hook should be in duty to see if the nose
hook really make a difference concerning accident rates.

The only information that I've seen so far is the Idaflieg flight test
that demonstrated that a gloder on a nose hook takes a lot more effort
and time to pull the tail of the tow plane up.

Bye
Andreas

On 6 Jan 2004 12:41:34 -0700, (Mark James Boyd)
wrote:


First of all, if the manual says to not use the C.G. hook
for aerotow, I personally wouldn't try it, even once.
But that's just me.


But what do you do with a glider like our ASW-27?
If only a CG hook is installed (yes, there are at least 150 27's
flying like this), it's fully certified for aerotow on the CG hook.
Since the new rules came out, all new 27's have a nose hook installed
and therefore this one MUST be used for aerotow.

Does the installed nose hook suddenly make the aerotow on the CG hook
dangerous?


OK, be prepared for me to completely change my tune. Are you guys
telling me the manual says that if it has only a CG hook, you can
aerotow with it, but if both hooks are present, the manual
prohibits aerotow on the CG hook for the ASW-27? And the
W&B limits and CG hook locations are identical for both
gliders?

If THIS is the case, a certainly can't argue with those
who see it as a simple paper shuffle. But I'd also say that in
this case a factory test pilot has surely flown that exact type of glider
with the CG hook in the exact position and flown it aerotow
that way. This means anyone who does it is NOT therefore a
test pilot.

Sounds like removing the nose hook just to "legally" aerotow
off the CG hook is a ridiculous paper shuffle hassle...
And yes, I did read the reasons why one might want to remove it.
Hmmm...so much for the manual, eh?

On 6 Jan 2004 20:01:17 -0700, (Mark James Boyd)
wrote:

OK, be prepared for me to completely change my tune. Are you guys
telling me the manual says that if it has only a CG hook, you can
aerotow with it, but if both hooks are present, the manual
prohibits aerotow on the CG hook for the ASW-27? And the
W&B limits and CG hook locations are identical for both
gliders?

Exactly.
The early 27's (as well as 24's, and probably all other glides that
are currently being produced in Germany) were only equipped with a CG
hook.
We retro-fitted one of our two DG-300's with a nose hook in order to
make it flyable for student pilots again who had been flying it safely
in aerotow the year before, but suddenly were forbidden to aerotow it
due to the new rules that demanded a nose hook for student pilots.


Sounds like removing the nose hook just to "legally" aerotow
off the CG hook is a ridiculous paper shuffle hassle...

More or less. If the nose hook was installed when the ship was
delivered, it must stay installed (yet some pilots seem to have found
an agreement with their inspector to remove the nose hook).

And yes, I did read the reasons why one might want to remove it.
Hmmm...so much for the manual, eh?

More or less.
The fact is undisputed that the nose hook indeed makes aerotows a
little easier and safer, therefore a nose hook definitely is an
improvement... but this does not mean that a CG hook per se is unsafe.

Bye
Andreas

On Wed, 7 Jan 2004 03:01:17 UTC, (Mark James
Boyd) wrote:

: Are you guys
: telling me the manual says that if it has only a CG hook, you can
: aerotow with it, but if both hooks are present, the manual
: prohibits aerotow on the CG hook for the ASW-27?

Under what circumstances would one tow with a CG hook when a nose hook
was available?

Ian
--

A pilot might aerotow on an aft hook when a forward hook is fitted if:

a/ The forward hook is unserviceable,
b/ The forward hook is taped over:
to increase performance,
to reduce noise,
to reduce drafts.

I think that the tug pilot or the organisation providing the tow would be
fully justified in refusing to tow the pilot in any of these circumstances.

If there were to be an accident, there might be a problem in claiming on the
insurance, and any investigation is likely to be adversely critical, even if
the tow hook position was not a factor in the accident.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.


"Ian Johnston" wrote in message
news:cCUlhtvFIYkV-pn2-LTEljpyteDPd@localhost...


On Wed, 7 Jan 2004 03:01:17 UTC, (Mark James Boyd)
wrote:

Are you guys telling me the manual says that if it has only a CG hook,
you can aerotow with it, but if both hooks are present, the manual
prohibits aerotow on the CG hook for the ASW-27?


Under what circumstances would one tow with a CG hook when a nose hook
was available?

Ian

On Thu, 8 Jan 2004 10:18:37 UTC, "W.J. \(Bill\) Dean \(U.K.\)."
wrote:

: A pilot might aerotow on an aft hook when a forward hook is fitted if:
:
: a/ The forward hook is unserviceable,

That would be ruled out by my " ... is available"

: b/ The forward hook is taped over:
: to increase performance,
: to reduce noise,
: to reduce drafts.

And that would be sheer stupidity - the cause, I reckon, of 90% of all
gliding accidents.

: I think that the tug pilot or the organisation providing the tow would be
: fully justified in refusing to tow the pilot in any of these circumstances.

Agreed. Or to impose conditions. At my club, any visiting pilot who
wishes to tow with a belly hook has to take a check flight in a
two-seater, towed with the belly hook, before s/he may fly,
regardlessof experience or qualifications. But then, it's a club which
lost one of its tug pilots, elsewhere, to an upset.

: If there were to be an accident, there might be a problem in claiming on the
: insurance, and any investigation is likely to be adversely critical, even if
: the tow hook position was not a factor in the accident.

The latter point worries me a bit. Accident investigations should, I
think, concentrate on what happened and what mattered. They shouldn't
kae side swipes at things the investigator doesn't approve of, if they
are irrelevant. In fact, investigations generally shouldn't be
adversely critical. We can all do that when we see what the cause of
an accident were!

Ian

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.


"Ian Johnston" wrote in message
news:cCUlhtvFIYkV-pn2-bKdumM0BMIOs@localhost...


On Thu, 8 Jan 2004 10:18:37 UTC, "W.J. \(Bill\) Dean \(U.K.\)."
wrote:

A pilot might aerotow on an aft hook when a forward hook is fitted if:

a/ The forward hook is unserviceable,


That would be ruled out by my " ... is available"


NO!

If the forward hook is unserviceable, then the glider is unserviceable for
aerotow.

Would you aerotow your Pirat on the aft hook if the forward hook is
unserviceable?

Would you winch launch a K21 on the forward hook (with no back release!) if
the aft hook is unserviceable? Would you do it if you could make the
forward hook back release? Would you wire launch any glider on the forward
hook (unless the C. of A. papers specifically allowed it) ?.

The glider has two hooks for a reason. If an apparently otherwise
identical glider has only one hook, that is a bad reason for assuming that
you can treat your glider hooks as interchangeable.



b/ The forward hook is taped over:
to increase performance,
to reduce noise,
to reduce drafts.


And that would be sheer stupidity - the cause, I reckon, of 90% of all
gliding accidents.


What seems stupidity to you may be a habit formed at a site where this has
become normal behaviour over the years.



I think that the tug pilot or the organisation providing the tow would
be fully justified in refusing to tow the pilot in any of these
circumstances.


Agreed. Or to impose conditions. At my club, any visiting pilot who
wishes to tow with a belly hook has to take a check flight in a
two-seater, towed with the belly hook, before she/he may fly,
regardless of experience or qualifications. But then, it's a club which
lost one of its tug pilots, elsewhere, to an upset.


If there were to be an accident, there might be a problem in claiming on
the insurance, and any investigation is likely to be adversely critical,
even if the tow hook position was not a factor in the accident.


The latter point worries me a bit. Accident investigations should, I
think, concentrate on what happened and what mattered. They shouldn't
take side swipes at things the investigator doesn't approve of, if they
are irrelevant. In fact, investigations generally shouldn't be
adversely critical. We can all do that when we see what the causes of
an accident were!


It was meant to worry you.

Like it or not, accident investigators tend to enquire, notice and comment
on the whole operation and not just the immediate causes of the particular
accident. And some underwriters are always on the lookout for an excuse
not to pay.

Have you never visited a site, or noticed a particular pilot or syndicate,
and said to yourself "there is an accident waiting to happen" ? Accident
investigators look for this, as well as the particular factors directly
leading to an accident.


Ian