The process for approving a permanent propeller gearbox (PGB) fix for the Airbus Defence & Space A400M will take longer than previously expected, according to propulsion system supplier Europrop International (EPI).

Earlier this year, EPI outlined an ambition to secure European Aviation Safety Agency certification for a "Pack 2" series of modifications to the TP400-D6 engine's Avio Aero-supplied PGB in the third quarter of this year. The activity involves design enhancements intended to reduce vibration and "reinforce endurance and reliability".

"EPI wants to provide a fully mature PGB configuration, which requires extensive analysis and tests," the engine consortium tells FlightGlobal, with the latter activity including "rig tests and full engine tests". "Consequently, we plan to achieve certification at the beginning of 2018,” it adds.


Airbus Defence & Space

As an interim fix, EPI secured EASA certification in July 2016 for a “truncated plug solution” to an issue that had affected some right-hand gearboxes on the TP400, which is used in a so-called “handed” configuration. The update has been retrofitted to all in-service A400Ms, and installed with new engines since the start of this year.

EPI says the interim solution is providing “strong relief to the operators” by removing the need to conduct on-wing inspections of the gearbox after every 20 flying hours. “This configuration is performing as expected on the fleet in service,” it adds.