A Motion Sensitive Explosive placed in the landing gear of the Fireflash by the Hood.

The device consisted of two parts: the auto-bomb explosive unit and an Mk.6 detonator unit. He placed it alongside the landing gear controls, to prevent the aircraft from landing, in Trapped in the Sky.

Hood auto bomb

The Hood, disguised as a maintenance man, gets aboard the Fireflash

Auto Bomb

The explosive unit (left) and the detonator unit (right)