Robinson R22 N404LE

Summary

On 27 January 2016 at about 16:57 local time, a Robinson R22 registered N404LE, operated by Academy of Aviation, LLC, was involved in an accident near Lindenhurst, New York, United States. 2 people were 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

27 January 2016 at 16:57

Classification

Accident

Location

Lindenhurst, New York, United States

Nearest airport

Republic (FRG)

Coordinates

40.6714, -73.3792

Aircraft

Robinson R22

Registration

N404LE

Category

Helicopter

Year built

2006

Engines

1

Operator

Academy of Aviation, LLC

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Farmingdale → Farmingdale

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA16LA094

Nobody was injured.

A rough running engine as a result of an intermittent failure of the left magneto for reasons that could not be determined, which resulted in a subsequent autorotation, impact with a sign, and rollover.

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

Read the full NTSB narrative

According to the flight instructor, the helicopter had been airborne for about 2 hours when it began to experience vibrations, which increased in intensity. He stated that the vibrations became “very violent” as he began to reduce engine power and were soon followed by the activation of the low rotor rpm horn and light warning system. The flight instructor performed an autorotation to a street in a residential area. The helicopter touched down and bounced, the main rotor blades struck a sign, and the helicopter rolled over onto its right side, which resulted in substantial damage to the airframe. A postaccident engine test run revealed that after the engine was started, it operated smoothly at idle and when the rpm was increased; however, when the left magneto was selected, the engine shut down. Both magnetos were removed and functionally checked on a test stand with no malfunctions noted. Subsequent disassembly of the left magneto revealed that the internal magneto timing was off by two teeth, which would have increased the gap between the distributor gear finger and the distributor block’s stationary electrodes; but not precluded the magneto’s ability to function. The flight instructor was using full carburetor heat throughout the accident flight. It is likely that the cumulative effect of carburetor heat, which would have reduced engine rpm, and an intermittent failure of the left magneto for reasons that could not be determined resulted in the engine roughness that preceded the autorotation.

Quoted verbatim from the NTSB record.