What type of circuit prevents both yaw contactors from being energized at the same time?

• A. Lockout circuit
• B. Interlock circuit
• C. Parallel circuit
• D. Series circuit

Answer: (A)

A lockout circuit exists to ensure only one path can be energized at a time, giving mutual exclusion for opposing actions like yaw controls. In practice, energizing one yaw contactor triggers a mechanism (often via a normally closed contact or latch) that blocks or drops power to the other coil. This prevents both contactors from being energized simultaneously, protecting the system from conflicting motions and mechanical stress.

Purely series or parallel wiring wouldn’t inherently prevent both sides from energizing: a series setup could still leave one path active under certain conditions, and a parallel setup could allow both coils to energize together. The lockout design explicitly enforces that only one can operate at a time, which is why it’s the correct choice here.