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Wikipedia presents this photograph of an F-14 Tomcat, with one variable-sweep wing swept forward and the other back:

An F-14 Tomcat with one wing swept forward and the other back

I was surprised to see that this configuration was possible; much less feasible or safe to fly with. My idle assumption, not being an aviator of any kind, was that this would be extremely unstable and difficult to handle. I would have assumed, given the prior assumption that the aircraft would be unstable, that the wings would have interlocks requiring them to be swept symmetrically, as a safety feature.

Is this photograph of a maneuver that is manageable and safe enough to perform routinely, or would doing this with the wings be an exceptional event or done only for testing? What kind of impact would this have on the aircraft's handling, given a forewarned, experienced pilot?

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I was the lead flight test engineer for Grumman on this project. The Navy had experienced a few mechanical failures that resulted in asymmetric wing sweep and this prompted a flight test program to determine the limits of controllability. We determined the aircraft could be flown slow enough where landing was feasible. Flaps were required to lower the approach airspeed to attempt any kind of shipboard landing, meaning both wings needed to be less than 50 degrees sweep. I think three aircraft recovered aboard ship with wings asymmetric to some extent and both forward of 50 degrees. We successfully landed at a field with wings at 20/60 and a fleet pilot eventually successfully landed at a field with a failure to the maximum possible split of 20/68.

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    $\begingroup$ Very cool -- welcome to Av.SE, and thanks for sharing that history here! Wonder what the ride felt like, with the wings that different. $\endgroup$
    – Ralph J
    Oct 14, 2022 at 2:35
  • $\begingroup$ Paul Conigliaro, I'm curious about one of the features of the F-14. Was it possible to lower the flaps with the wings swept back? Asking because that would make the aerodynamics very asymmetrical in this situation. $\endgroup$
    – Tom Miller
    Nov 6, 2022 at 20:24
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This was an intentional test run by Grumman in response to US Navy concerns about asymmetric wing sweep.

From The story of F-14A, Aircraft No. 3, BuNo. 157982

One of these [flight tests] was in response to concerns raised by the US Navy regarding asymmetrical wing sweep. No. 3 is best remembered for photo shown at right. A series of flight tests were conducted from December 19, 1985 to February 28, 1986. Grumman's Chief Test Pilot, Chuck Sewell, conducted several trials with the right wing locked in the forward position of 20 degrees, and positioned the left wing at 35, 50, 60 and 68 degrees of sweep in flight. 60 degrees was determined as the maximum for landing. In the event of an operational in-flight malfunction, Sewell found the aircraft to be acceptable for carrier landings in this configuration.

Evidently it was manageable, and safe enough that carrier landings were permitted with asymmetric sweep. There's no control available for the pilot of the Tomcat to intentionally asymmetrically-sweep the wings in flight, though.

How the handling qualities change I haven't seen reported anywhere. I agree with Robert DiGiovanni that you'd expect additional drag on the side with the extended wing, but the Tomcat has additional options on how to move spoilers and other control surfaces and it isn't clear to me if it can detect and respond to asymmetric sweep or if it's just up to the pilot to do so.

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This appears to be a very fancy version of a side slip, which can be routinely performed with many aircraft. Note the ailerons are set to roll left, with the outstretched right wing providing drag to yaw right. It is doing the same job right rudder would do.

Slipping to the left would also be consistent with "raise the dead" thrust asymmetry technique if this was a twin with the right engine out. Slipping to the left puts side force on the tail to counteract right yaw.

I would not do this particular maneuver too slow, particularly in that plane, where spin recovery would be more difficult. But a well trained pilot would be in a safe enough envelope for a few photo shoot takes.

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    $\begingroup$ I'm not sure what you are calling an aileron, but it looks to me like the right wing spoiler is up to counter the extra lift being produced. Also, your middle paragraph doesn't have anything to do with the question being asked. $\endgroup$ Apr 13, 2020 at 1:30
  • $\begingroup$ @Michael Hall great comments Mike. If you have any doubts, look at the left aileron. Side slip is also used to control a twin engine out. And no, spoiling lift and increasing drag on the extended wing (with all that torque) would be a no no. Notice the pilot is flying so well the rudders (in reserve) are still straight. $\endgroup$ Apr 13, 2020 at 1:39
  • $\begingroup$ They might be spoiling the right wing a little bit. Apparently that design did not make it to mass production. $\endgroup$ Apr 13, 2020 at 2:04
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    $\begingroup$ The F-14 doesn't have ailerons. Instead, it uses wing spoilers at low speeds, and differential 'tailerons' at high speed $\endgroup$ Apr 13, 2020 at 11:00
  • $\begingroup$ @Peter Kampf thanks, might have using those "televons" some too, and it would seem, in a slip to the left, the relative wind would lessen the sweep differential between the 2 wings, a "dihedral effect" from the swept left wing you have mentioned often in your writings. $\endgroup$ Apr 13, 2020 at 14:23

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