History of Flight
On July 17, 2009, about 0830 coordinated universal time (1130 local time), an MD Helicopters MD-530 (369FF), registration N974BW, operated by Presidential Airways, Inc., was destroyed when it impacted terrain at Camp Butler, approximately 20 miles east of Baghdad, Iraq. The flight was conducting aerial gunnery training under a company flight plan and military training range regulations. The helicopter was one of two that had arrived at Camp Butler from Baghdad, each carrying two pilots and two door gunners.
According to the pilot in command (PIC), the accident helicopter first landed at the range to provide a radio to range personnel while the second helicopter loitered to the south. After the radio transfer, both helicopters conducted a range sweep and completed firing runs. While the accident helicopter continued additional training, the second helicopter orbited off range to the south, and none of its crew observed the accident.
The PIC described the gunnery range as having an east-west track about 1 mile long with targets on both sides. During a telephone interview, he stated that a total of eight tracks were flown prior to the accident, with varying speeds from 60 to 90 knots. All eastbound tracks were flown by the copilot, and all westbound tracks by the PIC. After the final eastbound track, the copilot transferred control to the PIC, who then began a left-turning course reversal at an altitude of approximately 100 feet above ground. The PIC recalled seeing the copilot's finger moving toward the instrument panel, followed by being dragged along the ground.
In written responses, the PIC believed the copilot was directing attention to decaying rotor or engine rpm, which would have been associated with a rapid nose tuck and loss of altitude. The PIC noted that a standard preflight briefing had been conducted, including threats, weather, temperatures, routes, training elements, and emergency procedures. He calculated the density altitude at the time of the accident as approximately 3,100 feet. The PIC stated that the helicopter was operating properly with no warnings or changes in sound, and that the copilot did not speak or indicate anything wrong. No hostile fire was reported around the time of the accident.
Personnel Information
The PIC, aged 62, held an airline transport pilot certificate with rotorcraft-helicopter ratings and a flight instructor certificate. He had accrued 18,600 total flight hours, including 6,500 hours in the accident helicopter make and model. He had flown 66 hours in the preceding 90 days but none in the previous 30 days. His latest FAA second-class medical certificate was issued on January 6, 2009.
The copilot, aged 42, held a commercial pilot certificate with rotorcraft-helicopter and instrument helicopter ratings. He had indicated 6,275 total flight hours on his latest FAA medical application dated December 5, 2008, and operator records showed he had flown 15 hours in the preceding 30 days.
Aircraft Information
The helicopter was powered by a single Rolls Royce 250-C30 engine rated at 650 shaft horsepower, with 425 shp usable at takeoff. It had 2,662 hours of airframe time and 1,148 hours since engine overhaul. Its most recent annual inspection was completed on May 25, 2009.
Meteorological Information
Weather reported at Baghdad at 0900 local time included clear skies, visibility unrestricted, wind from 340 degrees at 15 knots gusting to 25 knots, no turbulence, temperature 38°C, and an altimeter setting of 29.75 inches Hg.
Wreckage and Impact Information
According to a draft U.S. State Department Diplomatic Security Service Memorandum, the helicopter appeared to have been traveling westward upon impact. The first point of impact was on the east edge of a dried-up pond, with disturbances indicating skid and tail rotor contact. The second point of impact was on the west edge of the same pond, with the fuselage coming to rest approximately 44 meters from the first impact. The tail boom and tail rotor were found separated from the main wreckage.
The wreckage was secured at Camp Butler, later moved to Baghdad, and eventually shipped to Anglin Aircraft Recovery Services in Clayton, Delaware, arriving in late January 2010. Examination on February 17, 2010, with NTSB participation, revealed that the fuselage was mostly consumed by fire. The tail boom exhibited fire damage and a separation with mechanical twisting consistent with main rotor blade strikes. The cockpit and aft compartment were destroyed by thermal and impact damage.
Flight control continuity could not be determined due to damage, but continuity was found at the tail rotor pitch change mechanism. Drive train continuity was confirmed only at the tail rotor gearbox. The transmission case was melted but attached. Main rotor blades showed damage consistent with flailing at operational rpm. The engine exhibited thermal and impact damage; examination revealed no pre-impact mechanical anomalies. The annunciator panel showed filament stretching in the ENGINE OUT warning bulbs, indicating the warning may have been illuminated at impact. However, no engine failures were identified.
Additional Information
According to the airframe manufacturer, the ENGINE OUT warning light activates when engine compressor speed falls below 55% or main rotor rpm below 453. The warning is accompanied by audio alerts and activation of the auto reignition system. The representative noted that the ENGINE OUT warning could illuminate during an accident sequence where the engine is running and main rotor blades contact the ground, or during rapid maneuvering causing rotor droop.