Wing Design

Pips · 9 February 2007, 03:59 PM

This is more an observation, but it seems to me that each nationality had a common preference regarding wing design.

For example, the British seemed to prefer wings of equal size and length eg Camel, Triplane, F.2b, D.H.2, B.e.2, S.e.5, D.H.4, Pup, F.K.8, Snipe, 1 1/2 Strutter, Vickers Vimy. There were exception eg Fairey, R.E.8, Handley Page; but they were in the minority.

The Germans tended the opposite way for their fighters, with the lower wing being much smaller eg Albatross D.111/V, Fokker Dr.1 and D.VII, Pfalz D.III/D.XII, Siemens-Schuckert. Most two-seaters and larger aircraft however had similar wing spans eg L.G.V, Roland, Halberstadt, Albatross C Series, Gotha.

The French too were quite mixed in wing variations.

My question is why the broad variety?

Were there different schools of thought at play here? Was any one wing design superior to the other? For example the Camel, Se.5, SPAD etc were renowned for their strength, while the Albatross and Nieuport series tended to shed lower wings in hard dives. Yet the Pfalz and Fokker D.VII were also regared as very strong aircraft.

Sreiko · 9 February 2007, 11:04 PM

Beleive or not there is a trend or fashion. And all of this is under of influence of some of leading designer. For excample Yugoslav post WW1 engeneer are schooled in France so there was influence of French design. In the early '80 all new trainer plane are look like the British hawk.

Greybeard · 9 February 2007, 11:43 PM

As far as I know, there weren't scientific reasons at the basis of certain choices. Mostly, practical ones.

"Thin" lower wings in french design, for instance, were to get better visibility and, having a single spar around which wing could rotate, to allow ground rigging for different angles of incidence, according to load and pilot preferences.

Germans initially had same chord wings, then copied french, without mastering really what they were doing, though (bitter surprise when first Albatros D.III lost its lower wing and many attempts to fix, up to late 1917 with D.Va). Triplanes were conceived just to improve visibility (narrower chord for a given total area) but, once again, germans gave sort of misinterpretation of it with Fokker Dr.I, were only downside visibility was improved by thinner and shorter lower wing, while upper one retained a wide chord.

GB

Pips · 11 February 2007, 02:00 PM

That's it? Structural strength and lift traded for improved visibility? No other reasons? Seems a harsh trade-off to me. And no doubt to the pilots who dies as a result of it.

What then would have been the reasoning behind having the lower wing the same width as the top wing, but less in length? Eg H.P's V/100 and V/400, Breguet's M.5, R.E.8, Bristol F.1, Ansaldo 1, to name a few.

There are also numerous examples of various Floatplanes with this wing configuration, but that I can understand.

SCMc · 11 February 2007, 04:41 PM

Cobby,

I do not know if this is the reason, but a short lower wing is less likely to hit the ground if the plane is not level during a landing.

Steve

Greybeard · 12 February 2007, 01:35 AM

Quote:

Originally Posted by Cobby

That's it? Structural strength and lift traded for improved visibility? No other reasons? Seems a harsh trade-off to me. And no doubt to the pilots who dies as a result of it.

Please consider a fighter pilot did have higher chance to die for lack of visibility: most part of casualties never did know what killed them.

Even nowadays wide-range cockpit visibility is important, reappraised on the basis of sixties and seventies conflicts, after it had been neglected in the era of radar and sensors.

Sorry about different span, same chord wings: I don't know.

GB

R Pope · 12 February 2007, 06:48 AM

Similar wings, like the SE5 and Sopwith Triplane, made manufacture easier and faster, the same ribs and jigs for all surfaces greatly speeding the process.
You didn't mention one other nationality-based oddity, the lack of dihedral on German planes. This always intrigued me, especially when I read about some of the British aces rigging it out of their SE's. Some of those fighters must have been like pushing a rope to keep them straight and level. Of course, S&L was the one thing you did not want in combat, but they must have ben taxing just "driving to work".

TomVrille · 12 February 2007, 04:52 PM

The greatest asset of a true biplane configuration (wings of equal span and chord, the same airfoil shape, and similar planform contours) is structural strength and torsional rigidity (resistance to twist). This stems from the basic box-beam structural model applicable to such configurations. Most of the lift is generated by the upper plane. Shortening the span of the lower plane reduces weight and drag without a proportional loss of lift, while retaining the biplane structural advantages. This is generally beneficial to performance. Additionally, there is some possible improvement in aileron efficiency without the lower plane 'shadow' effect.