The NTSB is calling on the U.S. Coast Guard to work with the Interior Department to mitigate methane discharges from offshore energy platforms in the Gulf of Mexico when helicopters are present. The recommendation follows two power-loss incidents in helicopters that led to accidents, one in 2011 and the other last year, on or near offshore oil platforms.
Gulfstream III, Farmingdale, N.Y., March 10, 2010–Soon after takeoff from Republic Airport (FRG), while climbing through 35,000 msl en route to Stuart, Fla., the crew of the GIII reported hearing a sound similar to a compressor stall, followed by a loss of power on the right engine. The pilot-in-command declared an emergency and initiated an in-flight engine shutdown.
While only one in five birdstrikes is ever reported, one unusual strike this past January 15, with an even more remarkable outcome, gained global attention and might bring advisories and eventually new certification and training standards to operators of all turbine-powered aircraft.
Hawker Beechcraft Beechjet 400, Jacksonville, Fla., Nov. 28, 2005–Both engines of the Flight Options Beechjet flamed out because high-altitude ice crystals that had accumulated on the P&WC JT15D-5 engines’ compressor vanes were ingested when the pilots pulled back the power levers to descend, according to the NTSB.
Cessna 500 Citation I, Oklahoma City, March 4–The Southwest Orthopedic and Sport Medicine Clinic’s Citation I was destroyed when control was lost soon after takeoff from Wiley Post Airport. The ATP-rated pilot, commercial copilot and three passengers were killed.
Hawker Beechcraft Beechjet 400A, Norfolk, Va., June 14, 2006–The NTSB said the probable cause of the dual engine flameout was the accretion of high-altitude ice crystals on the compressor vanes and their ingestion into the engine high-pressure compressor when the pilots pulled back the power levers. This caused compressor surges and the flameouts of both engines.
Hawker Beechcraft Beechjet 400A, Sarasota, Fla., July 12, 2004–According to the NTSB, the double engine flameout of the Flight Options Beechjet was caused by high-altitude ice crystals that accreted on the compressor vanes and were ingested into the high-pressure compressor when the power levers were retarded, causing compressor surges and flameouts.
Emergency AD 2003-08-52 was issued last month for the GE CT7-9B turboprop in response to 12 compressor-stall events in Saab 340Bs over a six-month period. The stalls occurred when pilots throttled back from takeoff power to climb power. Nine of the events involved engines that had the compressor variable geometry (VG) rigged to N1, one of two allowable rigging options that affords slightly higher performance at the expense of stall margin.
Several Beechjet flameouts have led the NTSB to make recommendations to prevent recurrences. The final recommendation, if adopted, would have wide implications: require the FAA and industry to pursue research to develop an ice detector that would alert pilots to internal engine icing and require that it be installed on new production turbofan engines and retrofitted to existing turbofan engines.