Originally Posted by
MAINJAFAD
...likely lost lock and went ballistic.
Failure mode unknown but SA-5 missiles do not usually go ballistic when lost-lock. The autopilot and downlink remain active, the engine can be throttled and the missile remains alive and awake until the power from the turbine runs out, killing the hydraulic power.
The 3-channel AP, inertial system and variable engine thrust is all about flying the most kinematically efficient profile. It does not guide in the traditional SAM sense, with different control laws for each phase of flight. Only in the short-shot mode does it default to a standard p-nav course guidance. A rather interesting system to operate and ahead of its time. The AIM-54 body shape owes more than a nod of its design to the SA-5.