N606BPMcdonnell Douglas Helicopter 600N · 1998

On April 27, 2014, about 1251 Pacific daylight time, a McDonnell Douglas Helicopters (MDHI) MD600N, N606BP, collided with terrain at Adelanto, California. Classic Rotors Museum was operating the helicopter under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The airline transport pilot (ATP) in the right seat sustained serious injuries, the commercial rated pilot in the left seat and one passenger in a rear seat sustained minor injuries. The helicopter sustained substantial damage during the accident sequence. The cross-country personal flight was departing when the accident occurred with a planned destination of Ramona, California. Visual meteorological conditions prevailed, and no flight plan had been filed.

Due to the nature of injuries to the ATP, he was unable to provide a statement as to the circumstances of the accident.

A Federal Aviation Administration (FAA) inspector interviewed the commercial pilot shortly after the accident. The pilot stated that he was getting evaluated in order to be able to fly the helicopter for the museum and at the controls during the accident as pilot-in-command (PIC). Prior to the checkout, he informed the ATP that he had 10,000 hours of flight time, primarily working off fishing boats in Guam. The commercial pilot could not provide the inspector with records that validated the flight time, or that he was a current, active pilot. The last medical dated December 15, 1993, indicated a total flight time of 3,300 hours. Attempts to locate and contact the commercial pilot for more information related to the circumstances of the accident were unsuccessful.

A witness reported that he had flown the helicopter with the ATP for 25 minutes prior to the accident flight, and completed one takeoff and one landing. He stated that all controls responded as commanded during his flight. The commercial pilot and a passenger then boarded for the next flight. The winds were from the west, and the helicopter was on a heading of 250 degrees. When it lifted off the ground, it initially tilted to the left looking like it was going to dynamically roll over. He saw the commercial pilot increase pitch on the collective; the helicopter yawed to the right 90 degrees, and tilted nose down. It left the ramp to the north of the property; the whole fuselage continued to have a left bank angle of almost 90 degrees, and it spun nose right. The helicopter spun approximately three revolutions until it sounded like the power to the engine was reduced to flight idle. Once the power was reduced to flight idle, the nose of the helicopter went down, the main rotor blade came in contact with a fence pole causing sudden stoppage, and a hard landing collapsed the right gear.

The National Transportation Safety Board (NTSB) investigator-in-charge, an FAA inspector, and investigators from MD Helicopters and Rolls-Royce examined the recovered airframe and engine on May 28, 2014, at the facilities of Flight Trail Helicopters, Mesa, Arizona.

Control continuity for the collective, cyclic, pedals and throttle were established. There was crush damage to the airframe with more damage on the right side than the left side.

Continuity of the drive train was established from the rotor hub through the transmission out to the NOTAR fan. The NOTAR gearbox chip detector was clean. The NOTAR rotated freely by hand.

The throttle moved freely from stop to stop, and followed movement of the throttle control in the cockpit.

The engine was left installed in the helicopter, and the engine was securely mounted. All external lines and connections were secure when checked by hand.

The compressor impeller displayed some leading edge foreign object damage (FOD), but it could not be determined if the FOD damage occurred prior to or during the event sequence.

The fourth stage turbine wheel turned freely. The rotor head rotated when turned one direction; it did not rotate when the wheel was turned the opposite direction. The first stage turbine blades were examined with a lighted videoscope. The wheel turned freely, and there was no evidence of damage on the blades.

The oil level for the engine was above the line. The oil was drained and the oil filter was clean.

The upper and lower magnetic chip detectors were clean.

The oil scavenge filter was clean.

Fuel was drained from the airframe low pressure fuel filter; it appeared clear.

N1 turned freely and was continuous from the compressor to the starter generator.

The fuel nozzle was normal in appearance.

No evidence of preimpact mechanical malfunction was noted during the examination. A detailed report is in the public docket for this accident.