A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Soaring
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Compare/Contrast: CG hook on aerotow vs. CG hook on winch



 
 
Thread Tools Display Modes
  #1  
Old May 25th 12, 03:54 AM posted to rec.aviation.soaring
son_of_flubber
external usenet poster
 
Posts: 1,550
Default Compare/Contrast: CG hook on aerotow vs. CG hook on winch

I've been told (and witnessed) that aerotow on CG hook is initially difficult for someone who has trained for aerotow with a "nose hook" (aka hook-forward-of-CG). Suppose this CG-hook-newbie were to take winch tow training (with CG hook). Would the winch training reduce the initial difficulty of a CG hook aerotow?

Do the difficulties/danger of aerotow with CG hook go away completely with training and experience?

What sorts of misadventures are reasonably attributed to aerotow on CG hook?

I understand why CG hook is superior for winch tow. No need to rehash that explanation.
Ads
  #2  
Old May 25th 12, 04:04 AM posted to rec.aviation.soaring
Darryl Ramm
external usenet poster
 
Posts: 2,403
Default Compare/Contrast: CG hook on aerotow vs. CG hook on winch

On Thursday, May 24, 2012 7:54:00 PM UTC-7, son_of_flubber wrote:
I've been told (and witnessed) that aerotow on CG hook is initially difficult for someone who has trained for aerotow with a "nose hook" (aka hook-forward-of-CG). Suppose this CG-hook-newbie were to take winch tow training (with CG hook). Would the winch training reduce the initial difficulty of a CG hook aerotow?

Do the difficulties/danger of aerotow with CG hook go away completely with training and experience?

What sorts of misadventures are reasonably attributed to aerotow on CG hook?

I understand why CG hook is superior for winch tow. No need to rehash that explanation.


There is increased risk that come from the directional squirliness. Can you reduce this with training. Sure. Can you eliminate any risk, no. Can you reduce it enough to feel comfortable. Maybe, but that is a personal risk decision, not something somebody else can tell you. But I've seen a few departures to the weeds with folks aerotowing with a CG hook. The attention getting ones involve crosswinds and narrow strips and/or tall grass... ending in ground loops. That cross wind handling, need to be ready to quick release etc. should be things to look at with an instructor.

Its not clear what you are flying or where, but some flight manuals do prohibit aerotowing with a CG hook (e.g. my ASH-26E does).

Darryl
  #3  
Old May 25th 12, 04:51 AM posted to rec.aviation.soaring
Bill D
external usenet poster
 
Posts: 746
Default Compare/Contrast: CG hook on aerotow vs. CG hook on winch

On May 24, 8:54*pm, son_of_flubber wrote:
I've been told (and witnessed) that aerotow on CG hook is initially difficult for someone who has trained for aerotow with a "nose hook" (aka hook-forward-of-CG). *Suppose this CG-hook-newbie were to take winch tow training (with CG hook). *Would the winch training reduce the initial difficulty of a CG hook aerotow?

Do the difficulties/danger of aerotow with CG hook go away completely with training and experience?

What sorts of misadventures are reasonably attributed to aerotow on CG hook?

I understand why CG hook is superior for winch tow. *No need to rehash that explanation.


Most glass two seat trainers (Grob, ASK-21, etc.) have both nose and
CG hooks so you can arrange to get some flight instruction in one aero
towing with the CG hook. Some countries prohibit aero tow with CG
hooks or require special training to do so. I can't say that 100% of
the dangers go away with training and experience but very nearly so.

I think winch training will improve any pilot - sometimes
substantially and not just with a CG hook.

For pilots trained on aero tow, the main danger with a CG hook is a
ground loop on the takeoff roll - a nose hook tends to keep the glider
rolling straight if a wing drops but the effect is small. If seen
many if not more ground loops with nose hooks.

A glider aero towing with a CG hook can easily climb above the tug
creating a very dangerous situation for the tug pilot but these upsets
happened primarily to pilots who had mostly winch experience and
little aero tow experience. It's as easy to stay in position behind
the tug but you have to be aware of the need to do so - you have to
really fly formation on the tug. The rope will not pull you back into
position.

  #4  
Old May 25th 12, 05:18 AM posted to rec.aviation.soaring
Eric Greenwell[_4_]
external usenet poster
 
Posts: 1,939
Default Compare/Contrast: CG hook on aerotow vs. CG hook on winch

On 5/24/2012 7:54 PM, son_of_flubber wrote:
I've been told (and witnessed) that aerotow on CG hook is initially
difficult for someone who has trained for aerotow with a "nose hook"
(aka hook-forward-of-CG). Suppose this CG-hook-newbie were to take
winch tow training (with CG hook). Would the winch training reduce
the initial difficulty of a CG hook aerotow?


No, and I suggest it may make you worse at aerotowing, because you learn
to put the glider in a steep climb. "Kiting" on tow is a bad problem;
"kiting" during a winch launch is normal operation.


Do the difficulties/danger of aerotow with CG hook go away completely
with training and experience?


No, but you can significantly reduce the risks with training and experience.

What sorts of misadventures are reasonably attributed to aerotow on
CG hook?


The worst is the increased potential for the aforementioned kiting; the
rest tend to happen on the ground with a chance for damage, but not less
risk to people.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
  #5  
Old May 25th 12, 06:05 AM posted to rec.aviation.soaring
b4soaring
external usenet poster
 
Posts: 7
Default Compare/Contrast: CG hook on aerotow vs. CG hook on winch

On Friday, 25 May 2012 03:54:00 UTC+1, son_of_flubber wrote:
I've been told (and witnessed) that aerotow on CG hook is initially difficult for someone who has trained for aerotow with a "nose hook" (aka hook-forward-of-CG). Suppose this CG-hook-newbie were to take winch tow training (with CG hook). Would the winch training reduce the initial difficulty of a CG hook aerotow?

Do the difficulties/danger of aerotow with CG hook go away completely with training and experience?

What sorts of misadventures are reasonably attributed to aerotow on CG hook?

I understand why CG hook is superior for winch tow. No need to rehash that explanation.


Also, CG hooks can back release if you get a lot of slack in the rope. The manual may suggest a method for blocking the back release - make sure you remove it before winching.
  #6  
Old May 25th 12, 08:46 AM posted to rec.aviation.soaring
BruceGreeff
external usenet poster
 
Posts: 184
Default Compare/Contrast: CG hook on aerotow vs. CG hook on winch

In the spirit of embarrasing admissions here.

I transitioned to aerotow at around 300 flights. Only ever winch
launched for the first part of my career.

By then I was a happy and reasonably competent Std Cirrus driver. (no
nose hook) I found aerotow difficult to get right because of over
controlling the Grob Twin Astir - I was not used to the momentum in
those heavy wings, and we were towing on CG hook so that I would be used
to it when I transited to the Cirrus - and we wallowed all over the
place behind the tug. To the despair of my instructors who no doubt
started wondering how I had flown solo...
Trying to simultaneously transition to aerotow, on CG hook, with a
completely new class of glider to me - put me back at ab-initio
competence for a while.

To shorten a long and frustrating experience - the winch experience on
the CG hook was little help. In fact the winch training can impede
progress. If you can fly aerotow competently the CG hook makes it only a
little more difficult. The aircraft will not self correct nearly as much
as on nose hook, so sloppy flying will be rewarded with diverging
excursions.

Then the good news - to get back to your questions - as soon as the CFI
let me go fly my own nimble little Cirrus it all went a lot better.
There is no substitute for experience - on type, and yes training will
help. The control harmony of what you are flying will influence the
outcome and what really counts is experience with aerotow in general,
and experience with what you are flying. Specifically the ability to fly
very precisely, and experience on the type you plan to fly on the CG hook.

CG hook specific misadventures:
If you get too high - especially with some designs, there is danger of
kiteing.
On the ground run, crosswinds are much more of an issue. No correcting
force on the nose so the grass at the side of the runway exerts an
inexorable attraction. You have to be on top of lateral control all the
time and be prepared to release the moment if goes sideways. Lateral
diversions on the ground run that are recoverable on nose hook tow will
result in a ground loop on the CG hook.
If your mount has airbrakes behind the CG you can help with directional
stability at any point by cracking them open.
Nose up pitch - the CG hook is below the centreline, so jerks on the tow
rope will tend to rotate the nose up. Especially on a light high drag
single seater like a Ka8. (this is one way to go kiteing)

(PS: The Grob STILL flies like a pig on CG hook - just my biased
personal view.)



On 2012/05/25 4:54 AM, son_of_flubber wrote:
I've been told (and witnessed) that aerotow on CG hook is initially difficult for someone who has trained for aerotow with a "nose hook" (aka hook-forward-of-CG). Suppose this CG-hook-newbie were to take winch tow training (with CG hook). Would the winch training reduce the initial difficulty of a CG hook aerotow?

Do the difficulties/danger of aerotow with CG hook go away completely with training and experience?

What sorts of misadventures are reasonably attributed to aerotow on CG hook?

I understand why CG hook is superior for winch tow. No need to rehash that explanation.


--
Bruce Greeff
T59D #1771
  #7  
Old May 25th 12, 02:38 PM posted to rec.aviation.soaring
Tony V
external usenet poster
 
Posts: 175
Default Compare/Contrast: CG hook on aerotow vs. CG hook on winch


CG hook specific misadventures:


On the ground run, crosswinds are much more of an issue. No correcting
force on the nose so the grass at the side of the runway exerts an
inexorable attraction. You have to be on top of lateral control all the
time and be prepared to release the moment if goes sideways. Lateral
diversions on the ground run that are recoverable on nose hook tow will
result in a ground loop on the CG hook.



Yes, to all of the above.

Plus, the glider type seems to make a difference. The Pegasus 101A that
I used to own a piece of always wanted to head for the weeds in any kind
of cross wind (and I've seen two others get damaged like that). OTOH,
the LS6-b that I now fly simply tracks straight under the same
conditions - no fuss.

Be sure that the glider is perfectly aligned before the take off roll on
a normal launch.

On an unassisted launch (read 'land out'), I put the down wingtip
slightly ahead, expecting the tip drag to straighten me out by the time
the wings level. How much of a lead depends on the surface type.

A nose hook is clearly superior for aero tow.

Tony "6N"
  #8  
Old May 25th 12, 03:13 PM posted to rec.aviation.soaring
Andy[_1_]
external usenet poster
 
Posts: 1,565
Default Compare/Contrast: CG hook on aerotow vs. CG hook on winch

On May 24, 7:54*pm, son_of_flubber wrote:

Do the difficulties/danger of aerotow with CG hook go away completely with training and experience?

What sorts of misadventures are reasonably attributed to aerotow on CG hook?


It all depends on the glider. There is no generic answer.

To put my reply in context I have 456 aero tow launches with CG hook
in ASW19b and 243 aero tow launches with CG hook in ASW 28.

Neither glider has any issue at all with pitch stability or
directional control while in flight. The ASW 28 has no issues at all
with directional control on the the ground. However, the ASW 19b with
its small tail wheel could be tricky in moderate to strong cross winds
at the start of the takeoff roll. I have no way of knowing how much
better it would have been with a nose hook. With proper positioning
of the glider and with proper pilot technique I was able to make
takeoffs in any wind condition other gliders or pilots could handle.

Unless you are planning to fly a vintage glider that is prone to
kiting, and if you are competent at aerotow with a nose hook, the only
issues you are likely to experience with a CG hook a

1. Risk of rope over-run and back release if the tug takes up slack
quickly. That's easily avoided by using the wheel brake.

2. Inadequate directional control at start of takeoff roll with cross
winds. This can be reduced by positioning the glider to compensate or
by using a wing runner who understands the problem and helps to keep
you straight.

The other side of the coin is that, as a tow pilot, I have been
subjected to moderate to severe abuse by pilots learning to fly the
Std Cirrus. As I said it depends on glider type and pilot skill
level.

A final data point - My ASW 28 has both a forward belly hook and a CG
hook. I choose to always use the CG hook for aerotow.

Andy (GY)





  #9  
Old May 25th 12, 03:31 PM posted to rec.aviation.soaring
Bill D
external usenet poster
 
Posts: 746
Default Compare/Contrast: CG hook on aerotow vs. CG hook on winch

On May 24, 10:18*pm, Eric Greenwell wrote:
On 5/24/2012 7:54 PM, son_of_flubber wrote:


No, and I suggest it may make you worse at aerotowing, because you learn
to put the glider in a steep climb. "Kiting" on tow is a bad problem;
"kiting" during a winch launch is normal operation.


A pilot would have to be pretty stupid to let that happen. (Learning
is where you ADD knowledge - not replace what was already there.)
Learn winch launch - you WILL become a better pilot.
  #10  
Old May 25th 12, 03:36 PM posted to rec.aviation.soaring
Bill D
external usenet poster
 
Posts: 746
Default Compare/Contrast: CG hook on aerotow vs. CG hook on winch

On May 24, 11:05*pm, b4soaring wrote:
On Friday, 25 May 2012 03:54:00 UTC+1, son_of_flubber *wrote:


Also, CG hooks can back release if you get a lot of slack in the rope. The manual may suggest a method for blocking the back release - make sure you remove it before winching.


If the CG hook is functioning properly (i.e. no weak springs), it
would take a LOT of slack to get a back release. So much so that
you'd be in front of the tug and probably want to release anyway.
Don't mess with the hook or you might make it malfunction completely.

Uncommanded releases are not a problem.

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
CG Hook for 1-26? [email protected] Soaring 1 October 29th 06 02:21 AM
Tow hook [email protected] Soaring 2 September 27th 06 02:16 AM
Elfe S4 Winch hook Derek Wilson Soaring 0 July 21st 05 11:07 AM
Tow Hook 337 for a 150-150 1JH Soaring 3 July 19th 05 06:35 PM
CG hook & Low Tow Ray Lovinggood Soaring 2 July 25th 03 06:20 AM


All times are GMT +1. The time now is 03:09 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Copyright 2004-2021 AviationBanter.
The comments are property of their posters.