The FAA and JAA requirements for Sustained Engine Imbalance (SEI) became applicable for Airbus with the introduction of the A340-500/-600 series aircraft.
The Sustained Engine Imbalance (SEI) is a result of a shaft support failure or loss of a complete fan blade with collateral damage. The condition after the engine is spooled down (rotation caused by aerodynamic forces) is also known as Windmilling*.
The Airbus A340-500/-600 is the first aircraft to show compliance with the Windmilling requirements, capable of continued safe flight and landing after partial or complete loss of an engine fan blade or shaft support failure. Aircraft interior parts such as Galleys, Stowages and Crewrests all have to comply with this new requirement.
IGB has been involved with the certification of interior parts for the windmilling requirements from the moment that these requirements became effective. In the past seven years we have realized several projects in close contact with Airbus. We have now extensive experience in the certification of aircraft interior units for the A318, A340 and A380.
Finite Element Analysis is used for both the strength of the unit and the fatigue requirements (endurance of metallic parts). Our Eigenfrequency analysis has been validated by dynamic testing in the Dutch Aerospace Laboratory (NLR).
*The windmilling requirements are resulting from FAA Issue Paper (IP) A-616, and JAA Certification Review Item (CRI) P-1018 (based on FAA Advisory Circular 25-24).