Here is the bottom line for AR: higher aspect ratio wings (for a given airfoil) have less induced drag as a percentage of lift produced. Thus you get a higher L/D.
Less drag translates to more excess power available which translates to better turn performance or maximum altitude attainable.
Regarding a good fighter aircraft, we want as much excess power as we can get in order to overcome increased induced drag due to tight turns or high altitude flight . This loosely translates to wanting a higher thrust to weight ratio.
Is it practical to have a very high AR wing on a fighter? Probably not due to the strength requirements needed to endure hard combat maneuvers. Modern fighters and WWI fighters are similar in some regards but the technology is so vastly different that comparing SR-71s or F-22s to a WWI fighter is probably not going to yield a very meaningful discussion.
Thnx for your input. So from this I would conclude that given all other things equal for example (not to bring jets in the discussion again):
A Cessna 152 with increased wing A/R has a higher ceiling.
But how much would I win? Let us assume I double wing A/R, using the same profile and offset etc. (all other things equal), creating twice the wingspan with half the chord length. (Basically creating some sort of glider plane wing). How much would I get as additional ceiling?
In practical terms, I would guess that the airframe drag bleeds so much power that the gained decrease in induced drag is minimal. Especially due to the fact that the increased lift only is a result through increased level speed by reducing the induced drag somewhat. Now if I go faster, I start to bleed more energy through increased drag of the entire airframe. The whole plane just won’t let me go as fast as the “better” wing would let me, as drag increases exponentially with speed increase.
The OP’s post was asking if the plane was indeed more maneuverable. Creating a large wingspan I feel is not the way to go. When I fly gliders with 20+ meters wingspan, I wouldn’t consider them very maneuverable, although they can turn impressively tight circles. But they have a roll speed less than an Airbus.
So my take is that there are better ways to decrease drag than making the wing a thin, narrow blade. A winglet will do. Wingtip tanks even help. The Piper Comanche flies better having them installed than without.
The ultra high A/R wing I’d consider the good option, when, like in a glider plane, you need a lot of lift to fly at minimal AoA at a comparatively slow airspeed. Being slow is just the result of having ultra-minimal thrust, because you want to keep your glide angle as shallow as possible.
But when you have an engine, just adding a constant speed prop will work wonders as you get a lot more trust from the same power at the crankshaft.
Lift I would never consider a constraint. Lack of speed is, such in maximum sustained turn. As said, sustained turn can well be improved by adding thrust. It is much more convenient to do than to sacrifice the planes roll abilities. If you have the best engine already, just make the wing area a bit larger. Significantly stretching the wings only comes into play when you’re already up high enough for even turbocharged engines drop power significantly. But then, the increasing minimum speed will get a problem. Wing flutter etc. is occurring in relation to TAS, not IAS.
When Kurt Tank stretched the wings on the Ta-152-H, he did so, because *lighter wing loading* would make a more shallow AoA possible above 12’000 meters, thus creating a faster plane. The added lift also made maneuvering easier up there. The decreased induced drag due to increased A/R was absolutely no issue, although surely a welcome effect. But only in this extreme case Kurt Tank would sacrifice one of the biggest assets of the Fw-190, its light ailerons, for added lift. IF induced drag was something Kurt Tank worried bout, why didn’t he make a higher A/R for all common Fw-190?
Another thing is: Planes with a high wing A/R are most always not maneuverable planes. Big gliders, they are anything but maneuverable, although they great “circlers” due to an obscenely low wing loading. This configuration is usually found in turboprop airliners. I’m only aware of Bob Hoovers Rockwell Commander that is great for stunting. And a plane with Bob Hoover on the controls is hardly your “control” for normal.
When you have a very exact specification on how your plane is operated and you have exhausted all your means in powering the plane, streamlining the hull, saving weight, etc, then you add the high A/D wing with the minimal required wing area (you want to keep the wing as small as possible to make it efficient at cruise speed) for given altitude and speed. Then it makes sense. But it is a tool to save fuel, not to make the plane agile.
I also fail to see a meaning correlation between wing A/R and service ceiling in real world GA planes. The Cessna 172 and the “stubby winged” Piper Cherokee 180 are very comparable aircraft. But the 172 has a ceiling of 14’550 ft, the Cherokee 160 has 15’000 ft. and the Cherokee 180 has 16’000 ft. service ceiling. So, the Cessna with the highest wing A/R loses out.
There is just no real world GA plane (or any non-turbocharged/gas turbine, pressurized) plane where wing geometry is a limiting factor for ceiling. Or name me one, as I couldn’t find any.
Although the better L/D ratio by increasing wing A/R may sound reasonable in theory, in the real world I still find it deeply impractical and even somewhat misleading. The fact that the claim per se is certainly correct is only a burden, because it is a design trend very much against the OP’s question.
You want to have a more maneuverable aircraft? Given all things equal, here’s my suggestions for practical design purposes:
- Drop weight.
- Increase power/thrust.
- Make better plane control surfaces.
- Make the plane smaller.
- Put the heavy stuff together near the center.
- Keep the plane structure strong enough for high g loading
Long wings will be weaker, they break in maneuvers while reducing roll rate to unacceptable levels, speaking of “more maneuverable planes”. High wing A/R makes the wing heavy, as the thinner profile will require it to be made stronger, thicker beams if made from the same material as the “stubby wing” and will go against the first and most important thing you should do, namely “dropping weight”. How much heavier would the glider wing Cessna be (if that wing was made from the same material as the traditional wing)? Wouldn’t that extra weight cancel out the decreased induced drag? Just make the wing a bit bigger and you get all the lift you’ll ever need. Or put winglets on it.
Telling from this, I would also put in question the L/D relationship. I would say you better go for the thrust-to-(specific)drag ratio, because thrust-to-drag ratio determines level flight acceleration, while thrust-to-weight, thrust-to-drag, lift-to-weight and lift-to-drag ratios all determine climb performance. Yes, thrust-to-drag is in steady state in all planes 1, but not during maneuvering. Thus, for antique planed you can lift-to drag as a measure, because you can’t go fast anyway and all you do is climbing after losing altitude in a maneuver.
It really depends on what “maneuverability” means to you, as gav detailed above. And if you want to go high, go fast. If you want to maneuver, go powerfull, small and stubby. Like the Pitts Special.