Does anyone use a tug tow hook that releases automatically whenglider kites?

On Saturday, February 22, 2014 1:58:28 AM UTC-6, GC wrote:
On 22/02/2014 16:17, Alan wrote:



...You don't get kiting if you fly normal "high" tow behind the towplane,

if you remain in control.



If you don't remain in control, starting from low tow is not going to

make a lot of difference.



Experience (tens of thousands of aerotows) shows there is an enormous

difference. The inadequate control and time to go from high tow to

kiting is orders of magnitude different from that required to go from

low tow to kiting. In fact, I've never heard of that ever happening.

Even with low time students. Kiting from high tow, however, is

apparently so common as to need a whole new system of electronic

whizzbangery and gallons of bandwidth to stop.



If the tug has just lifted off, being in low tow sounds a bit difficult,

but that would be a particularly hazardous time.



Yes. Liftoff is a time to be wary and we train accordingly.

Nevertheless, all I can say is that low tow has prevented kiting

accidents for many years. But don't take my word for it, keep this

ridiculous discussion going with another screwball idea for pivoting,

autoswivelling, pitch-sensing, stick-following nonsense.



If the issue is serious - as it was in Australia - flying low tow will

solve it. If it isn't - see my previous post.



GC







As for automatic methods to mitigate the problem, perhaps the solution

is not to modify tow planes, but to modify gliders. If the glider is

in a very high pitch attitude on tow, it might be a good time to automatically

release.



Another modification might be to attach the tow rope to the top of the glider.

This would cause the tow force to pitch the glider down.





Is this more of a problem when folks try to tow a slow glider like a 2-33 at

high speeds?



Alan


GC is making his point for low tows very convincingly - why is he immediately being ripped, Chris? Preparing and steering into low tow at a safe altitude, say 300', means to mentally and then practically pushing the stick forward and then holding in the low tow position. That's the opposite maneuver of what's leading to kiting. Drifting upwards takes you into the prop wash and again, it takes forward stick pressure to move into the safe spot. That feedback mechanism is correctly maintaining the intended safe spot while in the normal tow position only visual cues are being used.
I think I'll give the low tow a try, if ever that polar vortex over Chicago makes like tree...
Herb

At 14:28 22 February 2014, wrote:
On Saturday, February 22, 2014 1:58:28 AM UTC-6, GC wrote:
On 22/02/2014 16:17, Alan wrote:
=20
=20
=20
...You don't get kiting if you fly normal "high" tow behind the
towplan=
e,
=20
if you remain in control.
=20

=20
If you don't remain in control, starting from low tow is not going
t=
o
=20
make a lot of difference.
=20
=20
=20
Experience (tens of thousands of aerotows) shows there is an
enormous=20
=20
difference. The inadequate control and time to go from high tow to=20
=20
kiting is orders of magnitude different from that required to go
from=20
=20
low tow to kiting. In fact, I've never heard of that ever
happening.=20
=20
Even with low time students. Kiting from high tow, however, is=20
=20
apparently so common as to need a whole new system of electronic=20
=20
whizzbangery and gallons of bandwidth to stop.
=20
=20
=20
If the tug has just lifted off, being in low tow sounds a bit
diffic=
ult,
=20
but that would be a particularly hazardous time.
=20
=20
=20
Yes. Liftoff is a time to be wary and we train accordingly.=20
=20
Nevertheless, all I can say is that low tow has prevented kiting=20
=20
accidents for many years. But don't take my word for it, keep this=20
=20
ridiculous discussion going with another screwball idea for
pivoting,=20
=20
autoswivelling, pitch-sensing, stick-following nonsense.
=20
=20
=20
If the issue is serious - as it was in Australia - flying low tow
will=20
=20
solve it. If it isn't - see my previous post.
=20
=20
=20
GC
=20
=20
=20

=20

=20
As for automatic methods to mitigate the problem, perhaps the
soluti=
on
=20
is not to modify tow planes, but to modify gliders. If the glider is
=20
in a very high pitch attitude on tow, it might be a good time to
automa=
tically
=20
release.
=20

=20
Another modification might be to attach the tow rope to the top of
t=
he glider.
=20
This would cause the tow force to pitch the glider down.
=20

=20

=20
Is this more of a problem when folks try to tow a slow glider like
a=
2-33 at
=20
high speeds?
=20

=20
Alan
=20

GC is making his point for low tows very convincingly - why is he
immediate=
ly being ripped, Chris? Preparing and steering into low tow at a safe
alti=
tude, say 300',

If you wait 'till 300 feet the majority of the risk of a fatal kiting
incident is already behind you, once past 400 feet there is just about
enough height for the tow pilot to recover.

means to mentally and then practically pushing the stick
fo=
rward and then holding in the low tow position. That's the opposite
maneuv=
er of what's leading to kiting. Drifting upwards takes you into the prop
w=
ash and again, it takes forward stick pressure to move into the safe
spot.
=
That feedback mechanism is correctly maintaining the intended safe spot
wh=
ile in the normal tow position only visual cues are being used.
I think I'll give the low tow a try, if ever that polar vortex over
Chicago=
makes like tree...
Herb


I've been aware of the Australian preference for low tow and the reasons
for it for over 30 years. My own flight testing and experience lead me to
believe that it does not significantly reduce the probability of a kiting
accident.

On 23/02/2014 01:46, Chris Rollings wrote:

I've been aware of the Australian preference for low tow and the reasons
for it for over 30 years. My own flight testing and experience lead me to
believe that it does not significantly reduce the probability of a kiting
accident.

Well, Australia's experience shows that it does.

I would also say that, having flown in the UK, the Oz rules are
sometimes seen there as somewhat wussy - along the lines of "real men
don't fly low tow". Chris's irrational vehemence makes me think he may
be one of that 'sometimes' group.

GC

At 16:15 22 February 2014, GC wrote:
On 23/02/2014 01:46, Chris Rollings wrote:

I've been aware of the Australian preference for low tow and the
reasons
for it for over 30 years. My own flight testing and experience lead me
to
believe that it does not significantly reduce the probability of a
kiting
accident.

Well, Australia's experience shows that it does.

I would also say that, having flown in the UK, the Oz rules are
sometimes seen there as somewhat wussy - along the lines of "real men
don't fly low tow". Chris's irrational vehemence makes me think he may
be one of that 'sometimes' group.

I seem to recall reading somewhere in this thread that Australia does not
aerotow on C of G hooks, I think that is probably what accounts for the
better safety record.
I do fly low tow, for cross country tows and to teach students how to do it
and to get them used to flying through the prop wash so they are not
alarmed by encountering it accidentally for the first time.

GC

For those who consider using a nose hook largely solves the
problem of kiting, I suggest watching
http://www.youtube.com/watch?v=4MkCnVYa3VY
It is a video of a pilot's second solo flight in a K13 with an aerotow
launch using the nose hook. The pilot is distracted when the
airbrakes open, he looks out at the airbrakes, closes/locks them
and when he looks forward again the tug is disappearing below the
nose. The glider pilot releases. This is at 90m agl.
The commentary and text (in French) gives some extra insight and
analysis. CRIS is the acronym for the French pre-flight checks.
I met the tug pilot some months after this incident - he said that it
was very fortunate that the glider pilot released so promptly as the
towplane was starting to be tipped. It was a big lesson learnt for
him personally, not least to keep a hand VERY close to the release.
Enlightening and interesting thread...

On Saturday, February 22, 2014 10:25:23 AM UTC-6, Iain Baker wrote:
For those who consider using a nose hook largely solves the

problem of kiting, I suggest watching

http://www.youtube.com/watch?v=4MkCnVYa3VY


Excellent video.

But interestingly, not a case of kiting - more like the recent US case of upset by flying too high (distracted by open canopy). In the video (made by the pilot himself - bravo!) he remarks that the tow pilot realized something was wrong and released BEFORE the glider did. He then released to get rid of the tow rope trailing from his nose hook and flew his pattern. Pretty cool for a second solo...

I'll bet a new JS-1 that the Rallye towplane had a Tost hook!

In a scenario of the glider flying high due to inattention, with a nose hook, the climb should be slow enough for the tuggie to recognize and release (IF HE CAN - see Schweizer discussion!) because the glider pilot hopefully isn't just yanking back on the stick.

HOWEVER, if this same scenario had happened with a CG hook, it may have turned into a kiting incident, and could easily have been fatal for the tuggie..

Thanks for pointing out this video - I'm definitely showing it at our club's spring safety meeting!

Cheers,

Kirk

Further clarification about the tug upset video on YouTube, following first hand feedback from the tug pilot...

The tug had a French Aerazur hook, notorious for not releasing under tension. I guess issues with this hook led to the French pre-solo exercise of landing behind the tug. [I look forward to Kirk supplying me with a new JS1 !!!]

The tug pilot says the take-off felt normal, but during the initial climb the stick became harder...instantly he looked in the mirror and saw the ASK13 climbing like a winch launch...he didn't think, just pulled the red handle to release the rope. Maybe knowing that it was an Aerazur hook helped being decisive in releasing promptly. At the same time he felt the tug's tail lifting up and the tug's attitude was 45° down when he released. During debriefing, it was determined that the glider pilot released the rope just after the tug pilot. The tuggie hasn't said what height the tug was at before he recovered.

Not going to get into the semantics of calling this a kiting incident - while the glider was not excessively pitched up, it was high enough to upset the tug and could have been fatal if the tug pilot had not acted so quickly.

Iain

On Saturday, 22 February 2014 22:57:13 UTC, kirk.stant wrote:
On Saturday, February 22, 2014 10:25:23 AM UTC-6, Iain Baker wrote:
For those who consider using a nose hook largely solves the
problem of kiting, I suggest watching
http://www.youtube.com/watch?v=4MkCnVYa3VY

Excellent video.

But interestingly, not a case of kiting - more like the recent US case of upset by flying too high (distracted by open canopy). In the video (made by the pilot himself - bravo!) he remarks that the tow pilot realized something was wrong and released BEFORE the glider did. He then released to get rid of the tow rope trailing from his nose hook and flew his pattern. Pretty cool for a second solo...

I'll bet a new JS-1 that the Rallye towplane had a Tost hook!

In a scenario of the glider flying high due to inattention, with a nose hook, the climb should be slow enough for the tuggie to recognize and release (IF HE CAN - see Schweizer discussion!) because the glider pilot hopefully isn't just yanking back on the stick.

HOWEVER, if this same scenario had happened with a CG hook, it may have turned into a kiting incident, and could easily have been fatal for the tuggie.

Thanks for pointing out this video - I'm definitely showing it at our club's spring safety meeting!

Cheers,
Kirk

On Tuesday, April 29, 2014 12:12:00 PM UTC-5, wrote:
Further clarification about the tug upset video on YouTube, following first hand feedback from the tug pilot...



The tug had a French Aerazur hook, notorious for not releasing under tension. I guess issues with this hook led to the French pre-solo exercise of landing behind the tug. [I look forward to Kirk supplying me with a new JS1 !!!]



The tug pilot says the take-off felt normal, but during the initial climb the stick became harder...instantly he looked in the mirror and saw the ASK13 climbing like a winch launch...he didn't think, just pulled the red handle to release the rope. Maybe knowing that it was an Aerazur hook helped being decisive in releasing promptly. At the same time he felt the tug's tail lifting up and the tug's attitude was 45° down when he released. During debriefing, it was determined that the glider pilot released the rope just after the tug pilot. The tuggie hasn't said what height the tug was at before he recovered.



Not going to get into the semantics of calling this a kiting incident - while the glider was not excessively pitched up, it was high enough to upset the tug and could have been fatal if the tug pilot had not acted so quickly.



Iain


Iain, thanks for the update - good info! I used this video at our club's spring safety meeting and it was a great teaching tool.

I was unaware of the French Aerazur hook - the last Rallye I looked at (in La Teste, last year) had a Tost - so I assumed....

I'll be faxing you your new JS-1 as soon as I get it shrunk enough in the dryer to fit in the fax machine!

Cheers,

Kirk

A very nasty "out of position" event but not kiting, the glider was never
enormously nose up. That was a particularly extreme example of the sort of
event I described in the very first of the series of tests we carried out.

At 16:25 22 February 2014, Iain Baker wrote:
For those who consider using a nose hook largely solves the
problem of kiting, I suggest watching
http://www.youtube.com/watch?v=4MkCnVYa3VY
It is a video of a pilot's second solo flight in a K13 with an aerotow
launch using the nose hook. The pilot is distracted when the
airbrakes open, he looks out at the airbrakes, closes/locks them
and when he looks forward again the tug is disappearing below the
nose. The glider pilot releases. This is at 90m agl.
The commentary and text (in French) gives some extra insight and
analysis. CRIS is the acronym for the French pre-flight checks.
I met the tug pilot some months after this incident - he said that it
was very fortunate that the glider pilot released so promptly as the
towplane was starting to be tipped. It was a big lesson learnt for
him personally, not least to keep a hand VERY close to the release.
Enlightening and interesting thread...

Elevator power.
I may have missed the comment , but has anyone experienced
insufficient pitch down authority with full forward stick?
Our club had an incident in very rough conditions.
A PIK20B , belly hook, flown by a very experienced pilot,
was forced to release as a snatch caused an uncontrollable
pitchup. CG position not known, but the pilot was not large.
I did a calculation ( 30 years ago) to see if this was plausible
and indeed, if the CG was is near the aft limit with a PIK 20,
the transient pitchup couple in a snatch can probably overpower
full nose down elevator, thus initiating kiting.
There a re probably many other sailplanes susceptable to
this near the aft CG limit.
John firth

At 14:46 22 February 2014, Chris Rollings wrote:
At 14:28 22 February 2014, wrote:
On Saturday, February 22, 2014 1:58:28 AM UTC-6, GC wrote:
On 22/02/2014 16:17, Alan wrote:
=20
=20
=20
...You don't get kiting if you fly normal "high" tow behind the
towplan=
e,
=20
if you remain in control.
=20

=20
If you don't remain in control, starting from low tow is not
going
t=
o
=20
make a lot of difference.
=20
=20
=20
Experience (tens of thousands of aerotows) shows there is a
enormous=20
=20
difference. The inadequate control and time to go from high tow to=20
=20
kiting is orders of magnitude different from that required to g
from=20
=20
low tow to kiting. In fact, I've never heard of that eve
happening.=20
=20
Even with low time students. Kiting from high tow, however, is=20
=20
apparently so common as to need a whole new system of electronic=20
=20
whizzbangery and gallons of bandwidth to stop.
=20
=20
=20
If the tug has just lifted off, being in low tow sounds a bit
diffic=
ult,
=20
but that would be a particularly hazardous time.
=20
=20
=20
Yes. Liftoff is a time to be wary and we train accordingly.=20
=20
Nevertheless, all I can say is that low tow has prevented kiting=20
=20
accidents for many years. But don't take my word for it, keep this=20
=20
ridiculous discussion going with another screwball idea fo
pivoting,=20
=20
autoswivelling, pitch-sensing, stick-following nonsense.
=20
=20
=20
If the issue is serious - as it was in Australia - flying low to
will=20
=20
solve it. If it isn't - see my previous post.
=20
=20
=20
GC
=20
=20
=20

=20

=20
As for automatic methods to mitigate the problem, perhaps the
soluti=
on
=20
is not to modify tow planes, but to modify gliders. If the glider
is
=20
in a very high pitch attitude on tow, it might be a good time to
automa=
tically
=20
release.
=20

=20
Another modification might be to attach the tow rope to the top
of
t=
he glider.
=20
This would cause the tow force to pitch the glider down.
=20

=20

=20
Is this more of a problem when folks try to tow a slow glider
like
a=
2-33 at
=20
high speeds?
=20

=20
Alan
=20

GC is making his point for low tows very convincingly - why is he
immediate=
ly being ripped, Chris? Preparing and steering into low tow at a safe
alti=
tude, say 300',

If you wait 'till 300 feet the majority of the risk of a fatal kitin
incident is already behind you, once past 400 feet there is just abou
enough height for the tow pilot to recover.

means to mentally and then practically pushing the stick
fo=
rward and then holding in the low tow position. That's the opposite
maneuv=
er of what's leading to kiting. Drifting upwards takes you into the
prop
w=
ash and again, it takes forward stick pressure to move into the saf
spot.
=
That feedback mechanism is correctly maintaining the intended safe spot
wh=
ile in the normal tow position only visual cues are being used.
I think I'll give the low tow a try, if ever that polar vortex over
Chicago=
makes like tree...
Herb


I've been aware of the Australian preference for low tow and the reason
for it for over 30 years. My own flight testing and experience lead me t
believe that it does not significantly reduce the probability of a kitin
accident.