Robinson R44 II N247DB

Summary

On 12 August 2016 at about 18:25 local time, a Robinson R44 II registered N247DB was involved in an accident near Gunnison, Utah, 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

12 August 2016 at 18:25

Classification

Accident

Location

Gunnison, Utah, United States

Coordinates

39.0511, -111.8561

Aircraft

Robinson R44 II

Registration

N247DB

Category

Helicopter

Year built

2003

Engines

1

Operator

Not recorded

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Gunnison → Gunnison

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR16LA165

Nobody was injured.

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

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

Read the full NTSB narrative

The commercial pilot was nearing the end of his second agricultural application pass; about the time that he turned off the spray system, he heard a "pop" and felt a "thump" that shook the helicopter. After he observed chemical spray in the air and along the side of the helicopter, he pushed the "kill" button for the spray pump. As he was doing so, the engine rpm dropped, and the pilot heard the engine "sputtering." The pilot lowered the collective to re-establish main rotor rpm; the engine subsequently experienced a total loss of power. He entered an autorotation between 50 and 75 ft above the ground, and the helicopter landed hard. The spray system was recently installed, and the helicopter had flown about 16 hours since the installation. The spray system pump was mounted on the right side skid. The engine air filter compartment was located above and behind the spray pump. A postaccident examination of the spray system revealed that the plastic pipe nipple on the spray system fractured. The initial crack progressed through the wall of the nipple during flight and caused a pesticide leak. Examination of the internal and external surfaces of the engine intake air filter revealed no cake deposits. Because there was no evidence of chemical residue on the airframe between the engine and the air intake filter and the condition of the air filter was relatively clean, it is unlikely that the engine ingested enough chemical to cause the total loss of power. Additionally, the operator later had the engine successfully run in a test cell with no anomalies noted; therefore, the reason for the loss of engine power could not be determined.

Quoted verbatim from the NTSB record.