Closing MEL Items: Why Sooner is Better
It is not always possible to repair a system failure before the next flight. The MEL permits the dispatch of an aircraft with inoperative equipment or functions for a limited period of time, and under specific conditions, while maintaining an acceptable level of safety. Current in-service data shows an increase in the number of requests for MEL extension indicating an increase of departures with multiple open MEL items. Even if dispatch under MEL always guarantees an acceptable level of safety, it increases the risk of exposure to multiple failures with their inherent operational consequences. This article recalls the importance of fixing MEL items at the earliest opportunity to reduce this risk of exposure to multiple failures, and provides best practices where MEL extensions are necessary to maintain the highest possible margin of safety.
A Recall on the Correct Use of the MEL
The dispatch under a Minimum Equipment List (MEL) item enables the dispatch of an aircraft in a safe and airworthy condition when certain system functions or equipment are temporarily unavailable or inoperative. This enables the aircraft to continue earning revenue without compromising the safety of the flight.However, what are the MEL principles and are there good practices to apply when dispatching an aircraft with an MEL item in the technical logbook?
Pitot Probe Performance Covered On the Ground
Pitot probes inlet obstruction will affect accuracy of the air data parameters calculated from its measurements such as the aircraft airspeed and Mach number. Pitot probes inlet obstruction on the ground can be caused by unexpected sources such as sand, dirt, dust or insect nesting activity. This is why it is important to think about when to install Pitot probe covers for an aircraft on the ground to protect its air data system performance.