McDonnell Douglas 600 N208MP

Summary

On 21 July 2020 at about 11:58 local time, a McDonnell Douglas 600 registered N208MP was involved in an accident near Thompson Falls, Montana, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

21 July 2020 at 11:58

Classification

Accident

Location

Thompson Falls, Montana, United States

Coordinates

47.5597, -115.4395

Aircraft

McDonnell Douglas 600

Registration

N208MP

Category

Helicopter

Year built

1998

Engines

1

Operator

Not recorded

Operating rule

Part 133: Rotorcraft Ext. Load

Purpose of flight

External Load

Phase of flight

Not recorded

Route

Thompson Falls → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR20LA235

Nobody was injured.

A partial loss of engine power for reasons that could not be determined based on available evidence.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

While on an approach to the landing zone, the pilot lowered the collective to start a vertical descent to land. At that time, the engine and rotor speeds suddenly decreased, the helicopter yawed to the left and started to settle. Because the helicopter was approaching the ground fast, the pilot increased the collective to use the remaining engine power to cushion the landing. The helicopter impacted the ground, and the pilot rolled the throttle to idle, but noticed that engine speed and rotor rpm gauges were below the normal idle parameters. When he rolled the throttle to off, he heard a grinding "metal-to-metal" noise, and the rotor blades stopped spinning almost immediately. Data downloaded from the onboard incident recorder captured a “low rotor RPM” event during the flight, followed by “Flameout” and “Ng Low” triggers. According to the data, the full authority digital engine control system (FADEC) attempted to re-light the engine for the next 53 seconds until the throttle was rolled to cut-off; however, the engine did not restart. A postaccident examination of the engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation, and the reason for the low rotor rpm triggering event could not be determined.

Quoted verbatim from the NTSB record.