How does the emergency gear extension function?

The emergency gear extension typically utilizes a pressure relief valve to allow the landing gear to lower and lock into place when the normal hydraulic system fails or is not available. In this scenario, when a pilot encounters a hydraulic failure, the emergency system is engaged. The pressure relief valve allows the hydraulic fluid to flow in a manner that gives the landing gear the necessary force to extend and lock down safely.

Using the pressure relief valve ensures that even if the primary hydraulic system is compromised, the gear can still be safely deployed using residual pressure or gravity assistance. This is crucial in emergency situations where a safe landing is paramount. The mechanism allows for controlled operation without needing additional pumps or external power, which could be unavailable in emergencies.