B-58 Hustler Incident November 1959
@ Greenknight,
Reference the B-58 incident (airframe 55-664) 25 miles South East of Lawton, Oklahoma on the 7th of November 1959. This was a test of inflight shutdown and restart of the engines at supersonic speed. It has also been said that there may have been carrying out tests on side loads for the fin. I am not sure how true this is.
The test was simulating outboard engine failure at Mach 2. A failure of the Yaw Damper caused the aircraft to yaw at supersonic speed and the shock wave entered No. 4 engine while No. 3 was shut down resulting in a flat spin at supersonic speed causing the aircraft to break apart. A Convair crew was flying the aircraft at the time.
It was determined that a number of factors had contributed to the accident. The official report noted "design deficiency in that the directional restoring moments on the aircraft were not adequate for the test conditions". This was a deficiency in the tail fin structural integrity and a complex aerodynamic phenomenon that involved the aircraft’s large elevons and a small set of control surfaces at the wing root that served as trimming devices. Solutions were quickly put into place, and all B-58s were modified.
Hydraulic Systems
There are two separate and independent hydraulic systems, the utility and the primary, each having two engine-driven pumps maintaining a pressure of 3000 p.s.i. Both systems share in the operation of the flight controls, the elevons and rudders; should one fail the other system assumes the full load; should both hydraulic systems fail, the pilot has no means of controlling the aircraft and the crew must eject. The hydraulic systems also operate the landing gear, nose wheel steering, wheel brakes, tail turret, aileron, elevator and rudder damper servos.