I remember hearing that the F-101 had a tendency to pitch up with little to no provocation due to it's heavy wing-loading, wing design, and T-tail configuration.
According to this page:
http://www.456fis.org/F-101.htm
By mid-1956 the continued testing of the 29 F-101As which had been accepted by the USAF up to that time had turned up a number of structural, propulsion, aerodynamic, and armament problems. Perhaps the most serious of these was a tendency of the aircraft to pitch-up, a problem which was never fully corrected even after much effort. Brigadier General Robin Olds, who commanded a Voodoo wing, reported that it did not take very much to make a F-101A suddenly and without warning to go into pitch-up, even while cruising. The angle of attack needed to achieve lift with full flaps and drop tanks was very close to the pitch-up stall point, where the flow of air over the wings created a down flow over the tail slab. On January 10, 1956, Major Lonnie R. Moore, a Korean War ace with 10 kills to his credit, was killed in a F-101A pitch-up mishap at Eglin AFB, Florida.
I'm confused about what's being said here. Are they saying that the plane on takeoff with full fuel tanks with full flaps was near the pitch-up and stall-point? Or are they actually saying that they needed full flaps just to fly at high-altitude?