The SR-71 was an amazing piece of engineering. The panels actually didn't line up - as they expanded when it got warm. So basically at take off the aerodynamic

The SR-71 was an amazing piece of engineering. The panels actually didn't line up - as they expanded when it got warm. So basically at take off the aerodynamics of the plane were shot - you had to fly for a bit for it to hit normal performance (it also meant it literally leaked until it got hot enough and sealed).