The FAA proposes to issue an Airworthiness Directive (AD) to prevent high-pressure turbine hub failures on certain IAE jet engines, which could result in uncontained blade release, damage to the engine, and damage to the airplane.
The AD was issued in the wake of an incident that occurred on 18 September 2014. An Airbus A320-232, JetBlue flight number 1416, powered by two International Aero Engines (IAE) V2527-A5 turbofan engines, experienced a No. 2 (right) engine failure and subsequent undercowl fire during initial climb after departing Long Beach Airport (LGB), California. The flightcrew shutdown the No. 2 engine, discharged both fire bottles, and performed an air turnback to Long Beach. The airplane made a successful and uneventful single-engine landing at Long Beach Airport.
The NTSB determined the probable cause of the engine failure and subsequent undercowl engine fire was due to the fatigue fracture of a high pressure turbine stage 2 disk blade retaining lug that released two blades which impacted the low pressure turbine case causing a fuel line to fracture spraying fuel on the hot engine cases where it ignited. During a machining operation of the disk lug, a tool mark was introduced that set up the area for fatigue cracks to initiate.
The FAA determined the unsafe condition is likely to exist or develop in other products of the same type design. Consequenty a Notice Of Proposed Rulemaking (Nprm) was issued, asking relevant parties to respond to the proposed AD by June 6, 2016.