Originally Posted by
ORAC
IIRC the auto wing sweep was disabled because, once they started fatigue testing, they found it spiked if the wing was moving in the turn under G.
Moving the wings above 4G was prohibited on the GR to reduce stress on the pivot bearings, so this sounds reasonable.
Another issue (and potential difference from F-14) was that the already-poor turning performance was reduced even further if there was any delay in getting the wings forward as speed reduced during a hard turn. The lag between control input, changing turn rate and air data, smoothing the data to avoid continual wing movement, and finally the time for the wings and manoeuvre flaps to travel was such that better overall performance was said to be obtained by the pilot moving the wings manually in anticipation of each manoeuvre. That was the theory anyway; how the benefits tallied up against all the performance given away by pilots forgetting to make appropriate selections is probably an easy one to guess!