The EASA issued a new AD for the Eurocopter Super Puma intermediate gearbox (IGB) fairing gutter on December 21, calling for correction as described in Eurocopter service bulletins. It also requires reduced inspection intervals.
The intermediate gearbox fairing gutter first attracted scrutiny in 2005. At that time, one IGB fairing gutter separated from a Super Puma’s tail and interfered with the tail rotor’s inclined drive shaft. This condition, if not corrected, can lead to failure of the drive shaft, causing loss of the tail-rotor drive and reduced control of the helicopter, according to the most recent AD from the EASA. The French civil aviation authorities issued a corrective AD in 2005, and the EASA published a second one in 2007, after another separation report. At that time, the authorities believed the problem had been solved.
Then, another issue in the same area emerged. It revealed “a more extensive problem concerning the riveting of the gutter.” Another AD was issued in 2008, involving either repetitive checks or a terminating action, in this case modifying the gutter attachment on the IGB fairing. Eurocopter devised the modification.
Since the 2008 AD was published, operators have reported occurrences of cracks on the gutter of two helicopters, after the terminating action was implemented. Moreover, cracks were discovered, on other helicopters, in the IGB fairing on which the gutter is attached.
Operators of the Super Puma who have complied with the airworthiness directive have reported no problem, according to Eurocopter. All aircraft that have flown for 15 hours or more have been checked, a company spokesman told AIN last month. The next inspection must be conducted within the next 85 flight hours.
OEB Releases Final Report on Super Puma Crash
On December 15, a few days before the issuance of the latest AD for the Super Puma, the EASA’s Operational Evaluation Board (OEB) released its final report on the AS332L1/L2 and EC225 Super Pumas. The report highlights the need for thorough training on automation. Critical is “understanding how to use the automatics, what can go wrong with the automatics and how to cope when they do go wrong,” and “retaining the ability, when everything else fails, to recover the aircraft manually.” Also, the report insists the EC225 has “a number of subtle differences from the AS332L1/L2 variants.” If not fully understood, these differences could add difficulties during operations with one engine inoperative.