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Forward Swept Wings

Old 02-11-2002, 09:32 PM
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Default Forward Swept Wings

I'm in the process of finishing off my own design forward swept wing airplane and am looking for some advice.

Having never seen or talked to anyone who has actually flown one I'm not too sure what I should expect. According to theory it shouldn't be too different from a more standard design but it would be nice too hear about actual flight results.
Old 02-11-2002, 10:53 PM
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Default Forward Swept Wings

From what I've heard from assorted sources, forward swept wings are more unstable, where as backward swept wings are more stable, giving you almose a dihedral effect. The forward sweep can be done to look cool or make it more manueverable (becaues its more unstable)

Have you ever looked at a Duo Discus sailplane. They have a slightly forward swept wing. I think part of the reason is that they can thermal hunt better and then manuever in and out of thermals easier.

--Paul
Old 02-11-2002, 11:32 PM
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Default Forward Sweep

The main reason some two place sailplanes have forward sweep is to provide better visibility for the aft pilot. Forward sweep has another advantage. It provides tip stall margin for easier thermalling.
Old 02-12-2002, 05:20 PM
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Default Forward Swept Wings

That makes sense but then why wouldn't we see it on more fullsize aircraft than the 4 or 5 that we have actually seen. It has been proven to have a lower drag coefficient at higher sub-sonic speeds (right about where the Learjets fly). Every small plane has some problem with visiblity because the wing just gets in the way.

It just seems that there are enough benefits to justify the design. Is it that designers are scared to try something different. A lot has been said about twisting motions of the panels but that is easily overcome with composite materials.

It just bugs me.
Old 02-13-2002, 04:51 AM
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Default Forward Swept Wings

A lot has been said about twisting motions of the panels but that is easily overcome with composite materials.
In models maybe, in full size it may be a little harder to do, and a great deal more expensive.

I read a story in one of the homebuilt magazines on a guy who put swing wings on a full size Falco 260. When the wings were swept back it was very stable, when he swept them forward he almost scared himself to death. The plane became very quick in roll and pitch, pitch might be caused by the CG in effect being moved back, but the roll would have to have come from the forward sweep.

The cool thing about models is you won't die if you get it wrong.

Good luck.
Old 02-13-2002, 07:42 AM
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Default Forward Swept Wings

Forward sweep on a Bergefalke, for instance, didn't help my view as an instructor in gliders, so I don't see how it helps visibility.

Generally used on two place machines, which to me means effectively moving the Cg back and providing the instability to manoeuver. When you have to adjust from 220KMH between thermals down to 65KMH to enter a thermal you probably don't want to use both arms to haul back on the stick . Fingertip control is more preferable.
Old 02-15-2002, 01:14 PM
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Default Forward Sweep

I believe that the main reason for forward sweep on some two place gliders is to place the MAC where it needs to be and allow the main wing spar to still be placed aft of the cabin area.
Roger

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