Plane / Planes / Aircraft / Aeroplane / Airplane appreciation

Accelerate to M3.4 in level flight at 85,000', tilt the nose up. Given the level flight limit and speed of the Lightning, I can't see any reason why the SR-71 wouldn't have easily topped out at over 100,000'

From one of the links I posted previously...

As Angle of Attack increased, the aircraft reached a point where it departed from controlled flight rather than stalling out. A nose-up pitching moment developed as the AOA increased, which eventually becomes uncontrollable as the the critical AOA was reached. Subsonic, the critical AOA for pitch-up is approximately 18 degrees. At high Mach cruise, extreme caution was necessary if Habus were flying at altitudes above those for optimum supersonic cruise because the AOA could exceed 7-8 degrees. At 7 to 8 degrees AOA, any pitch transients caused by unstarts, increased bank angles, etc., could easily lead to an uncontrolled pitch-up manoeuvre.
I think it's fair to assume that when doing mach 3.4 at 85,000', pulling back on the stick wasn't considered a very good idea.