What is the role of a gear door interlock?

• A. It ensures gear movement does not occur unless doors are properly positioned, preventing interference and damage.
• B. It prevents gear movement if the landing gear doors are not fully closed after extension.
• C. It disables gear movement when the aircraft is not in the proper attitude.
• D. It is a mechanism that temporarily locks the gear in the event of hydraulic failure.

Answer: (A)

A gear door interlock is a safety feature that coordinates the movement of the landing gear with the position of its doors. It prevents the gear from moving unless the corresponding doors are in the correct position and properly latched. This guarantees that there is no interference between the gear and the doors as they operate, protecting both the doors and the gear from damage and ensuring a successful extension or retraction sequence.

In practice, if a door isn’t fully positioned or secured, the interlock stops gear movement, so you don’t end up with binding, misalignment, or damage to the door or gear bay. This broad role covers the essential need for correct door positioning before any gear motion, rather than addressing only specific scenarios like “doors must be closed after extension,” an aircraft attitude condition, or hydraulic failure.