PROCEDURES
Functional Check Flights
What does it take to be prepared?
Every flight is singular and needs to be prepared as such by flight crews, considering the state of the aircraft, the route, weather conditions, their own condition, the fuel quantity, the aircraft weight and balance… However, flights involving aircraft functional checks are flights with additional specific risks that deserve even more safety attention.
Indeed, these flights, when flown within an airline environment, differ significantly from “normal”, routine airline flights in many respects. They are sometimes called Technical Check Flights, Post Maintenance Check Flights, End of Lease Transfer Flights or Functional Check Flights. For the purposes of this magazine we shall use the abbreviation of Functional Check Flights, or put simply, FCFs.
Ensuring the safety of FCFs relies on various aspects and actors, at all organizational levels and phases. This special issue will provide you with an overview of what it takes to perform safe FCFs. It will address along a time / organizational unit line, the major aspects that, at each level, contribute to make FCFs safe. It is therefore arranged into the following sections.
Video: Crew room chat about Functional Check Flights
Special flights requiring special treatment
What is a Functional Check Flight?
Functional Check flights are non-revenue flights following maintenance actions or repairs that could affect the aircraft’s inherent aerodynamic and/or system characteristics and operational performance or before a return to lessor of the aircraft. It is recommended that they are performed by three airline crew members, two pilots and an engineer.
Therefore, in the airline world, FCFs are flights that differ from routine activities in many respects.
To start with, FCFs are “non-revenue flights”. As this activity is not the core business of airlines, it also disturbs to some extent the aircraft and crew availability schedules by mobilizing aircraft as well as crews and all the other needed operational personnel.
In addition, considering the objectives of a FCF, which is to get close to the limits and check the systems and the aircraft response, FCFs are unusual flights for airline crews.
A specific framework
Be it a matter of mind-set, of training, of documentation, of planning or all the other dimensions that contribute to making such flights safe, FCFs require specific preparation and conditions.
A preliminary condition to make such flights safe is to acknowledge this unique status and the need for special treatment of these flights at all levels.
From a regulation perspective, FCF specificities have been acknowledged and translated into the development of a dedicated regulation on Maintenance Check Flights that was issued in 2012 by EASA: Ref- EASA, NPA 2012-08. Maintenance Check Flights (MCF).
The regulatory requirements address a number of aspects contributing to the safety of FCF, namely:
- Flight crew requirements
- Additional crewmembers
- Training course
- Maintenance Check Flight Manual
In order to complete and reach beyond the regulatory material, the following sections provide some detailed and qualitative insights on key aspects that contribute to making FCF safe flights.
EASA REGULATION ON MAINTENANCE CHECK FLIGHTS AT A GLANCE
(fig.1) Summary of Functional Check Flights regulations
CONTRIBUTORS
Harry NELSON
Experimental Test Pilot
Simon PETERSON
Flight Test Engineer Instructor