Variable Geometry Wing Effectiveness

[AirLynx]

I was just wondering how effective the variable geometry wings on the F-14, MiG-23, MiG-27, etc. would be in a maneuvering fight. I remember reading about how one of the reasons the F-14 was retired was that it's swing wings were too expensive to maintain. What advantages would a swing wing give a fighter?

Sorry I meant to post this in the O'Club.

[Arlo]

I was just wondering how effective the variable geometry wings on the F-14, MiG-23, MiG-27, etc. would be in a maneuvering fight. I remember reading about how one of the reasons the F-14 was retired was that it's swing wings were too expensive to maintain. What advantages would a swing wing give a fighter?

More advantage than flaps.

[Krusty]

Depends on how heavy the mechanism is... On the Su-17 it was almost useless because it added too much weight to really help out. A conventional straight wing would have done that plane a lot more (just to use an example).

[eagl]

G limits also become a problem.

[Hoffman]

Sorry... I couldn't help it... but Modern Dogfighting as Falcon 4.0 taught me.



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"AWACS this is crossfire 31, I have a blip on my radar... range is... 24 nautical miles no IFF registered do we have any friendlies operating in box X?"

"crossfire 31, AWACS negative on friendlies."


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*Beep.... beep.... beeeeeeeeeeeeeeeeeep*



"AWACs crossfire 31, permission to engage target?"
"crossfire 31, permission granted."
"missile loose."

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"AWACs, crossfire 31 target destroyed continuing sweep."
"Roger good kill."

[Mar]

So what happens when the bogie has a radar warning receiver? Don't tell me they just sat there in Falcon waiting for the missile to hit em?

[Stoney]

I was just wondering how effective the variable geometry wings on the F-14, MiG-23, MiG-27, etc. would be in a maneuvering fight. I remember reading about how one of the reasons the F-14 was retired was that it's swing wings were too expensive to maintain. What advantages would a swing wing give a fighter?

Sorry I meant to post this in the O'Club.

Someone page Mace...

[nrshida]

It was essentially a solution to try and resolve the different requirements for high and low speed flight. Take the F-14 Tomcat for example, at one end of its performance it was a + Mach 2 aircraft for which highly swept or delta wings with less area are advantageous (also the centre of pressure moves aft as you go this fast), at the other end of its spectrum it had to land on a tiny carrier deck which demands greater lift at slow speeds.

For a low level supersonic strike aircraft like the Panavia Tornado, the reduced wing area not only decreases drag but also makes the platform more stable, not to mention more comfortable for the crew. Vital to the mission or you'll spill your tea on the final attack run to drop a nuke on the commies. Similar to the Tomcat the Tornado was intended for short runway operation (even has reverse thrust). When fully pivoted forwards the wings have full span flaps and slats giving greatly increased lift.

So basically it broadens the speed range over which the aircraft can efficiently operate and manoeuvre. I'm not sure about the Tomcat but the Tornado's sweep was automatic according to speed but the could be overridden by the pilot. Specifically Robert Shaw's book mentions fully forward swung wings for a downward spiral ACM.

The disadvantages of this approach is greater complexity, weight and cost, not the least of which was typically a very large and complex Titanium alloy box to mount the wing pivots and actuators and to distribute the load.

The more recent relaxed stability and also canard configurations have almost negated the need for this solution.

[mtnman]

The more recent relaxed stability and also canard configurations have almost negated the need for this solution.

Well, for now, anyway.

I don't see how man will ever really be able to master flight without radically increasing our ability to manipulate wing, fuselage, and tail configuration.

In the grand scheme of things our best airplanes are really awfully clumsy and crude contrivances.  Sure, they're complicated, noisy, fast, and well-advanced of anything else mankind has come up with...  They're still crude.  I saw the F22 Raptor doing it's thing at the EAA Airventure fly-in a few years back, and was still amazed by just how crude it was.  Really does the name "Raptor" an injustice, IMO.

We may be able to fly, and to transport and kill each other with our flying contraptions, but we've got a heck of a long way to go before we can even jokingly say that we've "mastered" flight.  I think it's exceedingly premature to say we've "negated the need" for something that may eventually open many doors.  We've barely scratched the surface when it comes to flight.

At one point, the balliste was considered to be such a formidable weapon that it was believed it had the potential end all warfare.  Who would stand against such a weapon?  It was cutting-edge, and it was probably argued that it "negated the need" for all sorts of things back then...

If you've been led to believe that we've "negated the need" to pursue this approach by anything you've read or heard from the military, or aircraft designers, etc, I'd recommend you take that with a grain of salt.  They have much to gain by misdirecting everybody and anybody who isn't in their "loop".  Improvements made in this department will likely yield money and power, so why not steer folks away from even thinking about it?

[Shuffler]

Make a paper airplane with short wings.... throw it slow then thro it fast. Now make a paper airplane with longer wings.... throw it slow then throw it fast.

[nrshida]

I don't believe I've said or implied that we've 'mastered' flight or anything else, I simply stated that from a design perspective one solution has been displaced, perhaps even temporarily, by another lighter, cheaper and more maintenance free solution.

I think you've chosen to form the impression I'm some kind of 'man is superior to nature' type but this isn't the case at all, I enjoy and appreciate both technical and natural accomplishments equally. We don't have so many aeroelastic airframes yet but then nature doesn't have supersonic Seagulls either.

If you were suggesting that nature has more elegant solutions then I agree with you for the most part, however mankind is also part of nature and only been doing this sort of thing for a very short period of time.

[mtnman]

I don't believe I've said or implied that we've 'mastered' flight or anything else, I simply stated that from a design perspective one solution has been displaced, perhaps even temporarily, by another lighter, cheaper and more maintenance free solution.

I think you've chosen to form the impression I'm some kind of 'man is superior to nature' type but this isn't the case at all, I enjoy and appreciate both technical and natural accomplishments equally. We don't have so many aeroelastic airframes yet but then nature doesn't have supersonic Seagulls either.

If you were suggesting that nature has more elegant solutions then I agree with you for the most part, however mankind is also part of nature and only been doing this sort of thing for a very short period of time.

I don't think the design solution has been "displaced by", I think it's more likely that it was " temporarily abandoned" or "given up on" because the means used to enable it on the first go-around were too inefficient, and nobody's come up with a better solution yet.  Like you mentioned, too heavy, etc... 

They're still working on it though.  The versions I've seen snippets of are still pretty primitive, but I think they're making progress of sorts.

I may have misunderstood your initial post.  I thought you were commenting on the need for a variable geometry wing being negated?  Maybe you just meant the attempts made to achieve that have so far been relatively poor (heavy, expensive, etc)?

I don't think it's really worth debating the man/nature/time spent flying thing, because we're obviously not designed for (nor changing to adapt for) flight.  We're "riders", we're definitely not "flyers".

And I agree, we can carry things, and go fast.  Not very conveniently, or very efficiently, but a lot of that is also due to all the gear we need to carry to enable us to do it at all.

[Rob52240]

I'm trying to picture an F-14 landing on the deck with in delta wing mode.  Anyone know the stall speed with the wings tucked back?

[nrshida]

I may have misunderstood your initial post.  I thought you were commenting on the need for a variable geometry wing being negated?  Maybe you just meant the attempts made to achieve that have so far been relatively poor (heavy, expensive, etc)?

There isn't a need for a variable geometry wing, there is a need to broaden the characteristics of lift and drag over a wide manoeuvring envelope for which swing wing was one solution, which I suggested has now been displaced by more recent developments including more powerful engines, relaxed stability, strakes and canards and also of great significance thrust vectoring.

Of course we can conjecture about the direction of future developments and that is indeed fun to do.

I don't think it's really worth debating the man/nature/time spent flying thing, because we're obviously not designed for (nor changing to adapt for) flight.  We're "riders", we're definitely not "flyers".

I wasn't talking about flying, I was talking about how mankind employs technology to create solutions whereas nature evolves over an extremely long period of time.

[superpug1]

On the 14 it was the best way to have a large, heavy jet that could haul as and also have the low speed stability to land on a deck and hang in a turning fight. long straigh wings have a higher coefficient of lift and allow lower take off speeds as well. without that technology, the B1 wouldnt be as capable as it is.