Glider crow-hops:

On 8/23/2012 6:54 PM, Bill D wrote:


Major snip of intervening nuance...


Bob, you will recall your wife's first flight in her 1-26. I was certain
she was good to go after training her in a 2-33 but she wasn't so sure. To
her, the 1-26 looked scary - it was her first single seat transition.

Actually, I'd forgotten that detail, Bill, until this reminder!

So, I tied two or three aero tow ropes together and towed her with my Jeep.
The first ground roll was below liftoff speed she over-controlled the
ailerons as I had promised she would. The next try she was straight and
true so I nudged the speed up a bit until the 1-26 lifted off to about 3
feet where she released as instructed. I wheeled the Jeep away from the
runway and she glided straight ahead about 100 yards to a perfect landing.
Her grin just wouldn't go away. Now she KNEW she could fly her 1-26.

Ground skims are a very old technique but they can still serve a purpose.

"I agree!" with both those closing statements. What I was seeking to convey to
the O.P. in this particular regard (the devil being in the details) was it may
matter to him (and his transitional success) how experienced every one of his
helpers is in whatever job he asks them to competently perform. Me knowing
none of those details, my guess is in today's world he's more likely to find
folks competent in aerotowing than in "crow hopping" at his home field.

I suspect we're both in agreement that reducing variables when transitioning
to a new-to-the-pilot ship is arguably "more safe" than increasing them is
likely to be.

In any event, I hope he lets RAS know how the transition goes...and how he
accomplishes it!

Bob W.

On Aug 23, 6:43*pm, BobW wrote:
On 8/23/2012 6:54 PM, Bill D wrote:

Major snip of intervening nuance...



Bob, you will recall your wife's first flight in her 1-26. *I was certain
she was good to go after training her in a 2-33 but she wasn't so sure. *To
her, the 1-26 looked scary - it was her first single seat transition.

Actually, I'd forgotten that detail, Bill, until this reminder!



So, I tied two or three aero tow ropes together and towed her with my Jeep.
The first ground roll was below liftoff speed she over-controlled the
ailerons as I had promised she would. *The next try she was straight and
true so I nudged the speed up a bit until the 1-26 lifted off to about 3
feet where she released as instructed. *I wheeled the Jeep away from the
runway and she glided straight ahead about 100 yards to a perfect landing.
Her grin just wouldn't go away. *Now she KNEW she could fly her 1-26.

Ground skims are a very old technique but they can still serve a purpose.

"I agree!" with both those closing statements. What I was seeking to convey to
the O.P. in this particular regard (the devil being in the details) was it may
matter to him (and his transitional success) how experienced every one of his
helpers is in whatever job he asks them to competently perform. Me knowing
none of those details, my guess is in today's world he's more likely to find
folks competent in aerotowing than in "crow hopping" at his home field.

I suspect we're both in agreement that reducing variables when transitioning
to a new-to-the-pilot ship is arguably "more safe" than increasing them is
likely to be.

In any event, I hope he lets RAS know how the transition goes...and how he
accomplishes it!

Bob W.

it's too bad the O.P. used the term "crow-hop"

Brad

Thanks for all the comments, and the few direct emails. Due to the time required I can't respond to all the issues raised.

Yes it is an Apis 13m, which was well built by Robert Mudd and then owned by Evergreen Soaring. I suspect Brad may have even flown it. I have read all the flying reports I can find about it, and I would respect anything Brad might add from his vast experience flying one.

My attitude still is that the crow-hop process I described is not a bad idea. And a few others here, with experience doing it, seem to agree. I have done many of them in new powered ultralights. For me it relieved the pressure of the transition, reducing the chance of “task over-load”, by getting more familiar with, and experience with some of the critical phases of flying before the actual flight, and thus reducing the risk.

I would also think that crow-hops in a towed glider are probably no big deal to do. The process is likely no different than practicing a rope break before the tow plane gets airborne, where you land straight ahead on the runway. So it is probably not a bad idea for others to practice it anyway.

A couple of useful things I did pick up on:

The comment which said watch out for PIOs rang a bell with me. I had that problem with one of the ultralights I designed and was crow-hop testing, when trying to test a new control while just a couple feet off the ground. That could be a problem in the Apis when reaching forward to release, or when unlocking the air brake. So I thought that unlocking the air brake first, like it would be anyway during a landing, and keeping the Apis on the ground with a forward stick while it gets up to speed, then release while still on the ground, then let it rise a few inches if there is enough speed left, then pull on the air brake, and then let it touch down and roll out like any normal landing.

The other concern might be allowing it to rise too high in a zoom climb, then stalling. But that is probably no different than any landing and not likely to happen to an experienced pilot.

Of course I'll discuss the crow-hop idea with my instructor, who is probably reading this RAS discussion anyway, and who has had a lot of experience in transitioning students to other gliders.

My Apis flying is still a few weeks away, so there is plenty of time to consider it, maybe even time for some others to try it and report back to RAS.

Thanks again,
Jerry Booker

Thanks for all the comments, and the few direct emails. Due to the time required I can't respond to all the issues raised.

Yes it is an Apis 13m, which was well built by Robert Mudd and then owned by Evergreen Soaring. I suspect Brad may have even flown it. I have read all the flying reports I can find about it, and I would respect anything Brad might add from his vast experience flying one.

My attitude still is that the crow-hop process I described is not a bad idea. And a few others here, with experience doing it, seem to agree. I have done many of them in new powered ultralights. For me it relieved the pressure of the transition, reducing the chance of “task over-load”, by getting more familiar with, and experience with some of the critical phases of flying before the actual flight, and thus reducing the risk.

I would also think that crow-hops in a towed glider are probably no big deal to do. The process is likely no different than practicing a rope break before the tow plane gets airborne, where you land straight ahead on the runway. So it is probably not a bad idea for others to practice it anyway.

A couple of useful things I did pick up on:

The comment which said watch out for PIOs rang a bell with me. I had that problem with one of the ultralights I designed and was crow-hop testing, when trying to test a new control while just a couple feet off the ground. That could be a problem in the Apis when reaching forward to release, or when unlocking the air brake. So I thought that unlocking the air brake first, like it would be anyway during a landing, and keeping the Apis on the ground with a forward stick while it gets up to speed, then release while still on the ground, then let it rise a few inches if there is enough speed left, then pull on the air brake, and then let it touch down and roll out like any normal landing.

The other concern might be allowing it to rise too high in a zoom climb, then stalling. But that is probably no different than any landing and not likely to happen to an experienced pilot.

Of course I'll discuss the crow-hop idea with my instructor, who is probably reading this RAS discussion anyway, and who has had a lot of experience in transitioning students to other gliders.

My Apis flying is still a few weeks away, so there is plenty of time to consider it, maybe even time for some others to try it and report back to RAS.

Thanks again,
Jerry Booker

One last thought...

I bought my first Glider before I was cleared solo, and wanted to fly it as soon as possible as well. Once I was cleared solo, I moved from the club 2-33 to the club 1-26. Both Schweitzers, not quite the same flight characteristics. But didn't need a crow hop to go fly the 1-26.

I asked my instructor for a check out in my Pilatus--never flew one, neither had most of the instuctors... But I found a club member who had, and we went over things while my instructor listened. I then got checked out in a Blanik L23 for practice with a tail dragger, and then my instructor let me try the Pilatus well before my check ride.

Did a full tow to 3k--just like I did for the first 1-26 flight. Good thing, because I found the Pilatus to be more "pitchy" than the previous gliders I'd flown. I practiced multiple manuevers at altitude before coming in for an approach and landing the same way I had in every other glider sortie, no issues. Had I tried a crow hop and pulled the spoilers out after release it would have been ugly---I would have been too abrupt, and the Pilatus does not have symmetric airbrakes like the Schweitzers or the Blanik, and with abrupt air brake movement you get pitch changes.

My point is this, If your instructor feels you are good enough to safely fly solo in single ship aircraft--which you will do and be cleared for the club ship as you mentioned--why would you try something different with your own plane?? Why would you risk finding something out about it doing something new in gliders?

It seems to me, as most have mentioned, it is best to go on a long tow to altitude, practice turns, stalls, airbrake extension and retraction, all the std stuff, then fly a normal, conservative pattern and come in and land. Your ship isn't unflown before, doesn't need testing before you should feel confident to fly it, so why not just fly it? Sit in it and play with everything, get comfortable putting it together and taking it apart, play with all the controls, then get a cockpit check from your instructor after both of you listen to anyone who's flown it before, and just go fly.

Cheers,
Squeak

Evan Ludeman wrote:
Crow hops are what you do if you have concerns about the
controllability of the glider. This is just a simple pilot transition
exercise. My $0.02.

Not the situation discussed here, but do a search for the children
gliding camps in Lithuania for a different, wonderful use of crow
hops.
--
Roberto Waltman

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On Friday, August 24, 2012 8:29:38 AM UTC-6, Roberto Waltman wrote:
Evan Ludeman wrote:

Crow hops are what you do if you have concerns about the

controllability of the glider. This is just a simple pilot transition

exercise. My $0.02.



Not the situation discussed here, but do a search for the children

gliding camps in Lithuania for a different, wonderful use of crow

hops.

--

Roberto Waltman



[ Please reply to the group,

return address is invalid ]

http://www.facebook.com/video/video.php?v=1607818468179

My "worth what you paid for it" opinion:

You are overthinking the problem. This is a known design with no unusual characteristics. Take a high tow, get the feel of the controls, do some practice approaches, feel the changes when you open and close the spoilers, etc.. By that time you will know how it flies - then land it.

Crow hops are not usually done anymore for a reason - they are not necessary for normal aircraft. And I can think of several ways for things to go wrong with a relatively high performace glider (it's not a primary!) at low altitude when you are concentrating on doing a lot in a short time. Wrong place to be if something distracts you, etc... Think about it. Get away from the ground so you have the options of sorting things out.

Crow hops for testing a new design or for no-instructor primary training is a completely different thing.

Kirk
66

On Aug 24, 9:31*am, "kirk.stant" wrote:

Crow hops for testing a new design or for no-instructor primary training is a
completely different thing.

I'm with Kirk on this. For a new pilot in a proven aircraft, I would
recommend a high tow that gets as far from the ground as quickly as
practical so you can figure out how to fly it and use its systems.

I'm one of the folks who recommended that Brad use what you might call
"crow hops" on his latest completion, the Tetra-15. The situation
there was very different from the one at hand. Brad is an experienced
pilot in sailplanes and hang gliders, but the aircraft was an unproven
example of an unproven design. And I should know, I designed and
helped build most of its important bits.

I supervised the main wing rigging and conducted the static test to
Utility category load factor, and I was pretty sure it was all going
to work out fine, but there's still an anxious gap between pretty sure
and absolutely certain. The crow hops ensured that if we miscalculated
or just plain missed something, it would come to light at a potential
energy (altitude) state and kinetic energy (speed) state such that
both could be brought to zero without bringing to bear a lethal energy
gradient (deceleration).

For the first flights, my main concerns were that we would find that
either we had mis-rigged the wings and it would have turning tendency,
or that we had miscalculated either weight and balance or stability
and control and it would not have good stability or control in pitch.
The "crow hops" would have revealed any of these conditions with ample
margin to rein it in before anyone or anything gets hurt.

However, it all turned just as we had hoped and planned. It flies
straight, has good stability and good control response, performs well,
and I can't get Brad to stop flying it long enough to show it off on
the ground. Which is as it should be, I think.

Thanks, Bob K.
http://www.hpaircraft.com
https://www.facebook.com/pages/HP-24...t/200931354951

On Aug 24, 6:31*am, J-Soar wrote:
Thanks for all the comments, and the few direct emails. Due to the time required I can't respond to all the issues raised.

Yes it is an Apis 13m, which was well built by Robert Mudd and then owned by Evergreen Soaring. I suspect Brad may have even flown it. I have read all the flying reports I can find about it, and I would respect anything Brad might add from his vast experience flying one.

My attitude still is that the crow-hop process I described is not a bad idea. And a few others here, with experience doing it, seem to agree. I have done many of them in new powered ultralights. For me it relieved the pressure of the transition, reducing the chance *of *“task over-load”, by getting more familiar with, and experience with some of the critical phases of flying before the actual flight, and thus reducing the risk.

I would also think that crow-hops in a towed glider are probably no big deal to do. The process is likely no different than practicing a rope break before the tow plane gets airborne, where you land straight ahead on the runway. So it is probably not a bad idea for others to practice it anyway.

A couple of useful things I did pick up on:

The comment which said watch out for PIOs rang a bell with me. I had that problem with one of the ultralights I designed and was crow-hop testing, when trying to test a new control while just a couple feet off the ground. That could be a problem in the Apis when reaching forward to release, or when unlocking the air brake. So I thought that unlocking the air brake first, like it would be anyway during a landing, and keeping the Apis on the ground with a forward stick while it gets up to speed, then release while still on the ground, then let it rise a few inches if there is enough speed left, then pull on the air brake, and then let it touch down and roll out like any normal landing.

The other concern might be allowing it to rise too high in a zoom climb, then stalling. But that is probably no different than any landing and not likely to happen to an experienced pilot.

Of course I'll discuss the crow-hop idea with my instructor, who is probably reading this RAS discussion anyway, and who has had a lot of experience in transitioning students to other gliders.

My Apis flying is still a few weeks away, so there is plenty of time to consider it, maybe even time for some others to try it and report back to RAS.

Thanks again,
Jerry Booker

Jerry,

The Apis Robert built was one of the nicest of the 13m kits that were
shipped over here. I have indeed flown it and it is a delight to fly.

My advice would be to talk with your CFI-G to determine if the
sailplanes you have flown will be suitable for transition to the Apis,
and I would say if you are handy in the 2 seat Blaniks you should be
just fine in the Apis. In fact the Albastar brochure says it is a
transition sailplane for the Blanik L-13.

You can use the flaps if you want but they are not really that
necessary for the first flights. I used 1 notch of positive just
because it gives a good view over the nose of the towplane. Leave them
at zero for landing, the ship can be landed just fine that way.

Make sure your airbrakes are locked until you need them; you mentioned
something about having them un-locked for a "crow-hop".........not a
good idea.

You have yourself a really nice sailplane there.................when
you are ready to move up, get one of Bob's HP-24 kits, I did and am
really happy with it.

Brad