Glider crow-hops:

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

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

Brad:

Thanks for all the info about flying the Apis. I'm getting closer to the first flights, probably preceded by some simple ground towed crow-hops to get used to it first.

A question:

Did your Apis have flaperon/wing gap seals? Mine had them, but they made the force on the stick in the roll direction very hard and sticky, at least on the ground.

The maintenance log for my Apis shows them only recently installed and with only about 3 flights on them, so I doubt they were well tested.

It seemed like not a good idea to have hard moving and sticky roll control, at least on the first flights, so I took them off of my Apis. It vastly reduced the stick force required to move the flaperons, and made it more like the elevator force.

I could replace them with new if required. What do you think?

Thanks,
Jerry Booker

On Aug 29, 6:21*am, J-Soar wrote:
Brad:

Thanks for all the info about flying the Apis. I'm getting closer to the first flights, probably preceded by some simple ground towed crow-hops to get used to it first.

A question:

Did your Apis have flaperon/wing gap seals? Mine had them, but they made the force on the stick in the roll direction very hard and sticky, at least on the ground.

The maintenance log for my Apis shows them only recently installed and with only about 3 flights on them, so I doubt they were well tested.

It seemed like not a good idea to have hard moving and sticky roll control, at least on the first flights, so I took them off of my Apis. It vastly reduced the stick force required to move the flaperons, and made it more like the elevator force.

I could replace them with new if required. What do you think?

Thanks,
Jerry Booker

Hi Jerry,

Robert was very conscious about trying to get the most performance out
of the Apis, that is why he installed those root fences. Mine did not
have them and removing yours already gives you a stick force
reduction, I would just leave them off. My Apis had light roll forces.

You probably don't need to do a crow hop, but if you do remember this
is a VERY LIGHT sailplane and will want to jump off the ground rather
quickly............put trim full forward!

Brad

I put the flaperon root flow fences on my APIS as well. I also have mylar
gap seal on the lower surface only, plus some interior "V" seal along the
top and bottom of the flaperons.

I've never flown the plane without the flow fences. If the seal strip
(fuzzy piece of velcro) is narrow and the flow fence is waxed, then these
add very little to the control forces. However, when I added the gap seals,
I did notice an increase in force at the stick to move the flaperons. While
this is noticeable on the ground, I've never really been aware of it in
flight.

FWIW.

John Scott

Thanks Brad and John.

I should have been more descriptive. I was referring to the mylar gap seals that cover the joint between the aft edge of the wing and the flaperon. The flow fences at the root didn't seem to be a problem, so I have left them on. I just removed the mylar seals, and got much less resistance to the stick movements.

I wanted to make sure it was safe to fly without them for the first flights.. I know they probably help with gliding performance, so I will later probably follow some good advice in a direct email and just install them on the bottom surface.

Thanks again,
Jerry Booker

On Aug 30, 6:01*pm, J-Soar wrote:
Thanks Brad and John.

I should have been more descriptive. I was referring to the mylar gap seals that cover the joint between the aft edge of the wing and the flaperon. The flow fences at the root didn't seem to be a problem, so I have left them on. I just removed the mylar seals, and got much less resistance to the stick movements.

I wanted to make sure it was safe to fly without them for the first flights. I know they probably help with gliding performance, so I will later probably follow some good advice in a direct email and just install them on the bottom surface.

Thanks again,
Jerry Booker

So now we're adding up new pilot, new glider, new manuevers (crow-
hops) not practiced with other gliders before, glider not flown by
instructors the pilot can get checked out by, new tow method (ground
not air) and, the latest, uncertain status of mylar seals and other
"improvements" to the control system, so glider flying in unknown and
un-test flown configuration. All at once.

I think enough advice has been dispensed in this thread about useful
approaches to glider test flying, transitions to new gliders, etc.
etc. It doesn't seem to be sinking in though. I hope someone at the
airport where this all is going to happen will perk up.

John Cochrane

That's why "Hey, watch this!" are so famous as the last utterances of so many amateur engineers, scientists, and yes...test pilots.

Hopefully, not in this case.

On Aug 30, 6:07*pm, RAS56 wrote:
That's why "Hey, watch this!" are so famous as the last utterances of so many
amateur engineers, scientists, and yes...test pilots.

As amusing as that might seem on the surface, that is exactly what
happened to a good friend of mine in August of 1987:

http://www.ntsb.gov/aviationquery/br...13X31829&key=1

Thanks, Bob K.