If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
|
Thread Tools | Display Modes |
|
#1
|
|||
|
|||
On Thu, 16 Jun 2005 02:09:30 GMT, Gord Beaman
wrote: Ed Sullivan wrote: On Sat, 11 Jun 2005 00:04:10 -0400, vincent p. norris wrote: Friend of mine said at lunch today that the upper wings of biplanes have no dihedral. Hementioned specificlaly the Stearman PT-17. I believe he was mistaken. I know the Sopwith Camel upper wing was flat but I think the PT-17 and most other biplanes have dihedral in both wings. Any expert comments? Thanks. vince norris Some biplanes have sweptback wings which provide the same effect as dihedral. My parasol Jungster II has sweepback and no dihedral. Ed Sullivan Why is that Ed?...dihedral provides lateral stability by making the 'downgoing wing' increase it's lift while the 'upgoing' wing's lift decreases, so how does the 'sweep-back' provide lateral stability? The reference escapes me, but I have read that so many degrees of sweep back is the equivalent of an estabilished amount of dihedral. All I know for sure is that this little sucker only has a 21' span and it is as steady as a rock. It will go for miles without touching the stick. |
#2
|
|||
|
|||
Ed Sullivan wrote:
On Thu, 16 Jun 2005 02:09:30 GMT, Gord Beaman wrote: Ed Sullivan wrote: On Sat, 11 Jun 2005 00:04:10 -0400, vincent p. norris wrote: Friend of mine said at lunch today that the upper wings of biplanes have no dihedral. Hementioned specificlaly the Stearman PT-17. I believe he was mistaken. I know the Sopwith Camel upper wing was flat but I think the PT-17 and most other biplanes have dihedral in both wings. Any expert comments? Thanks. vince norris Some biplanes have sweptback wings which provide the same effect as dihedral. My parasol Jungster II has sweepback and no dihedral. Ed Sullivan Why is that Ed?...dihedral provides lateral stability by making the 'downgoing wing' increase it's lift while the 'upgoing' wing's lift decreases, so how does the 'sweep-back' provide lateral stability? The reference escapes me, but I have read that so many degrees of sweep back is the equivalent of an estabilished amount of dihedral. All I know for sure is that this little sucker only has a 21' span and it is as steady as a rock. It will go for miles without touching the stick. Ok, thanks...I know that sweepback will increase fore and aft stability by making the critical fore and aft CG limits 'farther apart' but I sure can't see how it affects lateral stability...anyhoo...if you find out could you tip me off? Thanks Ed. -- -Gord. "I'm trying to get as old as I can, and it must be working 'cause I'm the oldest now that I've ever been" |
#3
|
|||
|
|||
On Fri, 17 Jun 2005 01:06:53 GMT, Gord Beaman
wrote: stick. Ok, thanks...I know that sweepback will increase fore and aft stability by making the critical fore and aft CG limits 'farther apart' but I sure can't see how it affects lateral stability...anyhoo...if you find out could you tip me off? Thanks Ed. This is not a complete explanation, but it might help. http://avstop.com/AC/FlightTraingHan...Stability.html |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Waco Biplane Down at KSBA | Larry Dighera | Piloting | 3 | June 6th 05 02:33 PM |
ANG Woman Wing Commander Doesn't See Herself as Pioneer, By Master Sgt. Bob Haskell | Otis Willie | Military Aviation | 0 | March 18th 04 08:40 PM |
Wing tip stalls | mat Redsell | Soaring | 5 | March 13th 04 05:07 PM |
Props and Wing Warping... was soaring vs. flaping | Wright1902Glider | Home Built | 0 | September 29th 03 03:40 PM |
An Affordable Homebrue 60 in DS machine | Grant | Soaring | 0 | August 8th 03 03:52 AM |