Robinson R44 II N440EM

Summary

On 3 August 2019 at about 20:05 local time, a Robinson R44 II registered N440EM, operated by Wallin Agricultural Aviation, was involved in an accident near Lyons, Nebraska, United States. One person was on board and one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

3 August 2019 at 20:05

Classification

Accident

Location

Lyons, Nebraska, United States

Coordinates

41.9375, -96.4731

Aircraft

Robinson R44 II

Registration

N440EM

Category

Helicopter

Year built

2013

Engines

1

Operator

Wallin Agricultural Aviation

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Lyons → Lyons

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN19LA250

1 person had minor injuries.

The engine's low cylinder compression, which resulted in low rotor rpm and a subsequent dynamic rollover following landing on soft terrain.

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

Read the full NTSB narrative

The airline transport pilot of the agricultural aerial application flight stated that as the helicopter entered the field to be sprayed, the low rotor rpm annunciation sounded. He attempted to recover rotor rpm, but the rpm continued to decay rapidly. He then used the remaining rotor rpm to cushion a landing onto the field. As the helicopter touched down, it slid about 150-200 ft before the skid dug into soft dirt and the helicopter rolled over. Post-accident examination of the engine by the operator revealed that the no. 6 cylinder had more leakage/lower compression than the previous 100-hour recorded compression checks. Reduced compression on one or more cylinders would have reduced excess power available to maintain a rotor RPM and altitude.

Quoted verbatim from the NTSB record.