Perlan High Altitude Tow Plane

It was to be Germany's answer to the U-2, if Wikipedia is to be believed.

Yes, that's why they are registered as gliders.

Ernst

Maybe it was something I ate, but I had a strange thought last night on towing really high.

What if you put a cg tow position on the tow plane and payed out cable from the tow plane winch launch style?

3/16 spectra is 100feet per pound, or 500 pounds for 50k feet. This weight would sometimes be carried by the tow plane's wings and sometimes by the glider's. The line on the tow reel would never be under tension, so you would not need an impossibly strong reel.

Logistics would be interesting to say the least, perhaps:

Launch like a normal aerotow with a tail connection point on the tow and a cg hook on the glider. Use 200 feet of tow rope.

Climb normally to something safer like at least 10kfeet. Perhaps to the tow plane's limit.

Transition the front end of the rope from tow plane tail to tow plane upper CG. Certainly use windows in the bottom of the glider and some computer help. Fouling the tail on the tow is a concern. Perhaps position the glider high and to the side or use a vtail. Definitely a trickey maneuver.

Pay out the other 49,800 feet of tow rope as the glider climbs.

Release both ends and pick up the rope in the ocean.


Definitely something I ate, but fun to think about.

On Friday, August 17, 2018 at 9:08:11 AM UTC-4, wrote:
Maybe it was something I ate, but I had a strange thought last night on towing really high.

What if you put a cg tow position on the tow plane and payed out cable from the tow plane winch launch style?

3/16 spectra is 100feet per pound, or 500 pounds for 50k feet. This weight would sometimes be carried by the tow plane's wings and sometimes by the glider's. The line on the tow reel would never be under tension, so you would not need an impossibly strong reel.

Logistics would be interesting to say the least, perhaps:

Launch like a normal aerotow with a tail connection point on the tow and a cg hook on the glider. Use 200 feet of tow rope.

Climb normally to something safer like at least 10kfeet. Perhaps to the tow plane's limit.

Transition the front end of the rope from tow plane tail to tow plane upper CG. Certainly use windows in the bottom of the glider and some computer help. Fouling the tail on the tow is a concern. Perhaps position the glider high and to the side or use a vtail. Definitely a trickey maneuver.

Pay out the other 49,800 feet of tow rope as the glider climbs.

Release both ends and pick up the rope in the ocean.


Definitely something I ate, but fun to think about.

Stu,
I think that has actually been done already in Russia a while back. I put a reference to an article describing that process in our 'winchdesign' forum but since Yahoo got hacked, most of the links to those references are lost..
The glider was towed up like a normal aero-tow. Then, the line was paid out and the tow plane started a descent which allowed the glider to climb like it would in a winch launch.

Uli
'AS'

On Friday, August 17, 2018 at 8:55:12 AM UTC-5, AS wrote:

Stu,
I think that has actually been done already in Russia a while back. I put a reference to an article describing that process in our 'winchdesign' forum but since Yahoo got hacked, most of the links to those references are lost.
The glider was towed up like a normal aero-tow. Then, the line was paid out and the tow plane started a descent which allowed the glider to climb like it would in a winch launch.

Uli
'AS'

Described in the book "Without Visible Means of Support" by Richard Miller. A very good read.

Oh, and the Russians also did testing where they towed a glider up and intentionally jettisoned parts of it in flight to determine controlability.

Steve Leonard

"This is not a toy and its mission is not play."

Yeah, maybe so, but it still looks like fun and an amazing, challenging project. Best of luck to all your endeavors. Say Hi to Jim, Jackie, Morgan, Sandra, Stewart, Liz, Tim, Tago and all of the other team members I will remember about two seconds after I hit "Post Entry."

Do I recall correctly that Einar Enevoldson descibed the Egrett as the
worst plane he ever flew (and considering some of the candidates at
NASA Dryden, that would be an amazing distiction).

At 02:01 24 August 2018, wrote:
"This is not a toy and its mission is not play."

Yeah, maybe so, but it still looks like fun and an amazing, challenging
pro=
ject. Best of luck to all your endeavors. Say Hi to Jim, Jackie, Morgan,
Sa=
ndra, Stewart, Liz, Tim, Tago and all of the other team members I will
reme=
mber about two seconds after I hit "Post Entry."

"He has not so much brain as earwax."

William Shakespeare, Troilus and Cressida Act V, Scene 1