The Hawaii incident has indications of a known issue with the GFE engine.
Not what the AW&ST article reports Sultan. If you don't have access, I can copy it to you, here is an extract...
"Investigation of a fatal accident in May involving a Bell-Boeing MV-22B Osprey tiltrotor transport points to an
undiagnosed failure mode in the Osprey’s trouble-prone propulsion system and has resulted in tight restrictions on restricted visibility landing (RVL) operations. The preliminary report findings—disclosed in documents obtained by Aviation Week—also reopen questions about an April 2010 fatal accident involving a U.S. Air Force CV-22B in Afghanistan. In that case, a senior officer dismissed investigators’ focus on engine problems and put blame on the pilots.
A major modification to fix the Osprey’s perennial problem—damage to engines caused by the dense and high-energy dust cloud the aircraft creates when landing on any loose surface—is under development, but testing will not be completed until late 2017 and the cost and time required to retrofit the fleet is unknown.......
Two U.S. Marines died, and two pilots and 18 other occupants were injured May 17 when an MV-22B crashed while attempting an RVL at Bellows AFS on Oahu, Hawaii...... The likely cause of the power loss, according to the document, was that the engine ingested sand containing reactive minerals—classified as calcium, magnesium, aluminum and silicon (CMAS) compounds—which melted in the combustor and solidified on the fixed first-stage turbine vane. This restricted airflow and reduced surge margin, but indications of these conditions to the aircrew “are not sufficient,” the report says. Throttle movement can trigger a surge with no other warning......
The Navair report identifies three earlier surge events related to reactive sand, one of which—on Aug. 26, 2013, at Creech AFB, Nevada—resulted in a Class A mishap and the loss of the aircraft in a postimpact fire. In addition, surveys of flight operations have found six more “rapid power loss events” in areas where there is known to be reactive sand.
The problem is compounded by lack of essential data. The Rolls-Royce AE1107C has not been tested for its resistance to CMAS ingestion. The problem is different from the engine’s long-running issue: compressor-blade erosion caused by ingested particles, which gradually saps performance until the engine is overhauled........
The newly discovered risk factors in the Hawaii accident parallel known information about the first Osprey combat loss, an Air Force CV-22B that crashed in Afghanistan in April 2010......