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WEM
12-31-2010, 04:31 PM
This comes in 2 parts:

1) Could you launch a paraglider from the back of a Hercules C130 transport plane (or any other plane for that matter) at 26,000 ft, travelling at, say, 200mph?

2) Supposing that was possible, how would the high altitude affect the glider's performance? I imagine the thinner air would mean a steeper glide angle, but faster speed. But then I could be missing something, not being a paraglider-user myself.

Thanks,

Stijn Hommes
12-31-2010, 05:47 PM
I checked with my father who is a paragliding pilot.

1) You could launch from the back of such a transport plane at 26000 ft (nearly 8 km) but you'd need extra oxygen and carefully calculate when to open the glider. At this speed, it's not a good idea to lay it out inside the plane before launch because the backwards speed would almost certainly cause the glider to stall. Instead you'd have to pack it carefully so it opens quickly and do a sort of parachute/basejump out of the plane and open the glider before your gravitational velocity is too high. This approach has also been used by pilots who wanted to launch from bridges or hot air balloons.

2) I'm not sure about the glide angle, but the record holder I read about said his glider was faster in the thinner air.

Source: http://www.e-lijn.nl/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=001265;p=2

There is also an English forum that might offer you more help: http://www.paraglidingforum.com/

WEM
12-31-2010, 10:24 PM
I checked with my father who is a paragliding pilot.

1) You could launch from the back of such a transport plane at 26000 ft (nearly 8 km) but you'd need extra oxygen and carefully calculate when to open the glider. At this speed, it's not a good idea to lay it out inside the plane before launch because the backwards speed would almost certainly cause the glider to stall. Instead you'd have to pack it carefully so it opens quickly and do a sort of parachute/basejump out of the plane and open the glider before your gravitational velocity is too high. This approach has also been used by pilots who wanted to launch from bridges or hot air balloons.

2) I'm not sure about the glide angle, but the record holder I read about said his glider was faster in the thinner air.

Source: http://www.e-lijn.nl/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=001265;p=2

There is also an English forum that might offer you more help: http://www.paraglidingforum.com/

Thanks very much Stijn. That's very helpful.

That's very interesting about the base-jump. If you went out of the back of a Hercules, you'd probably have to jump backwards, because once you were out you'd be travelling fast, forwards. Not something I'd like to do, but then it's only my MC, so what-the-hell :)

I had a look at the forum. Google Translate did enough of a job that I could follow the discussions.

Thanks again,

Williebee
12-31-2010, 10:32 PM
Wow, thanks Stijn. Good info.

I was wondering if it would be possible to free fall, then parachute first, to slow the descent enough not to destroy the glider when it was deployed at a certain elevation point.

Besides, that would be SO much more James Bond. :)

Stanmiller
12-31-2010, 10:52 PM
Thanks very much Stijn. That's very helpful.

That's very interesting about the base-jump. If you went out of the back of a Hercules, you'd probably have to jump backwards, because once you were out you'd be travelling fast, forwards. Not something I'd like to do, but then it's only my MC, so what-the-hell :)

I had a look at the forum. Google Translate did enough of a job that I could follow the discussions.

Thanks again,

Hoo-ah, talk about hairy. Dunno what the airspeed for jumping from a C-130 is, but stepping off the ramp at least 120 KIAS with a hangglider stowed in a fifteen-foot bag that'd become a giant sail as soon as it hit the slipstream? Serious credibility issue there, as I dunno if your guy could even hold on to the thing, much less control it enough to assemble it at terminal velocity.

Much better for him to use a wingsuit. That would let your intrepid hero fly much more believably. ;)

I believe there's at least one former paratrooper that hangs around here. Maybe he'll chime in.

Stan

Stijn Hommes
01-01-2011, 01:02 AM
The pack probably wouldn't be 15 feet if you fold it right. Also, while it might look like you get an enormous shock when a parachute or glider deploys, there is actually no such thing. The effect of being swept up when a parachute deploys in a film is the result of the visual effect created by the cameraman falling while the parachutist merely slows down.

The crucial thing is to deploy it before hitting terminal velocity. Otherwise the lines holding your glider together will snap for sure.

Stijn Hommes
01-01-2011, 01:04 AM
That's very interesting about the base-jump. If you went out of the back of a Hercules, you'd probably have to jump backwards, because once you were out you'd be travelling fast, forwards. Not something I'd like to do, but then it's only my MC, so what-the-hell :) It doesn't really matter how you jump as the speed of the plane is probably too fast to fly with. You'd need to freefall a little to lose your horizontal speed. That's why you need to be so careful when to deploy. Not too soon, but not too late either.

WriteKnight
01-01-2011, 05:34 AM
Don't confuse a hang glider with a paraglider. One has a rigid frame - the hang glider - the other is like a parachute - a parafoil more precisely.

Stanmiller
01-01-2011, 06:22 AM
Don't confuse a hang glider with a paraglider. One has a rigid frame - the hang glider - the other is like a parachute - a parafoil more precisely.

Oops.

thothguard51
01-01-2011, 06:35 AM
Basically, you are talking about what I believe is called a Halo Jump.

Oxygen is required and the suits are very much like a wing suit...

Halo Jumpers go through a series of maneuvers that slow them down and also allows them to get their barrings. They usually don't pull the cord until the last minute or so.

Watch the James Bond movie Golden Eye to see one in action...

Stanmiller
01-01-2011, 07:17 AM
WEM, If your guys are military, there's a heads-up display the US military uses called PARANAV (http://www.rockwellcollins.com/ecat/gs/ParaNav.html) that gives real-time position, ground track, and bearing to target information to the jumper.

Stan

KQ800
01-03-2011, 11:18 PM
This comes in 2 parts:

1) Could you launch a paraglider from the back of a Hercules C130 transport plane (or any other plane for that matter) at 26,000 ft, travelling at, say, 200mph?

2) Supposing that was possible, how would the high altitude affect the glider's performance? I imagine the thinner air would mean a steeper glide angle, but faster speed. But then I could be missing something, not being a paraglider-user myself.

Thanks,

1, Yes.

2. What you are referring to is called a HAHO, High altitude High opening jump.
From Wikipedia "HALO"
HAHO

The HAHO technique is used to airdrop personnel at high altitudes when aircraft are unable to fly above enemy skies without posing a threat to the jumpers. In addition, HAHO parachute jumps are employed in the covert insertion of military (generally special forces) personnel into enemy territory, in circumstances where the covert nature of an operation may be compromised by the loud noise of parachutes opening at low altitude.
In a typical HAHO exercise, the jumper will jump from the aircraft and deploy the parachute at a high altitude, 1015 seconds after the jump (typically at 27,000 feet (8,200 m) or so). The jumper will use a compass (http://en.wikipedia.org/wiki/Compass) or GPS (http://en.wikipedia.org/wiki/Global_Positioning_System) device for guidance while flying for 30 or more miles. The jumper must use way points and terrain features to navigate to his desired landing zone, and correct his or her course to account for changes in wind speed and direction. If deploying as a team, the team will form up in a stack while airborne with their parachutes. Usually, the jumper in the lowest position will set the travel course and act as a guide for the other team members.


Here is a link to a parachute PDF. according to the specs the speed of aircraft must be less than 150 KAS (Knots relative to surrounding air, not true speed). There is also a chart regarding relative descent or something, hope it helps.

http://www.airborne-sys.com/pdfs/_AS-Website_Marketing_PDFs/2-TROOP%20PARACHUTES%20HIGH%20PERFORMANCE%20RAM-AIR/Hi-Glide/Hi%20Glide.pdf

Stanmiller
01-03-2011, 11:48 PM
Good stuff.

One more detail to supplement KQ's comment on HAHO jumps.

HAHO jumpers can go off the ramp at higher than 150 KIAS. But to minimize 'chute loadings with the weight of the jumper plus the 100-150 pounds of battle rattle usually carried, they wait to pull until they have slowed to terminal free-fall velocity for the altitude.

Stan

Williebee
01-03-2011, 11:52 PM
Don't confuse a hang glider with a paraglider. One has a rigid frame - the hang glider - the other is like a parachute - a parafoil more precisely.

ah. oops x 2.

WEM
01-05-2011, 01:58 PM
Wow guys. That's some seriously good info.

The C-130 stalls at 132 knots, so my MC's pilot would probably go down to around 170. Too near to stall speed and turbulence could take you below stall speed.

It looks like HAHO is the way to go. The purpose of the jump is indeed to put an agent into hostile territory, unnoticed. The altitiude is right and the range would allow the aircraft to stay outside territorial waters. I'll get my MC off to training camp :D

Stanmiller, Stijn, Thothguard51 and KQ800, thanks again guys, I'll go and do some reading.

Stanmiller
01-06-2011, 03:56 AM
WEM said,
I'll get my MC off to training camp

If he's military or CIA, he'll go to the Vertical Wind Tunnel course at Ft Bragg, then to Yuma for the Military Free Fall Parachutist Course.

Hoo-ah!

Stan

Williebee
01-06-2011, 04:16 AM
he'll go to the Vertical Wind Tunnel course at Ft Bragg

Am I the only one who went "I wanna go!"?