Robinson R22 BETA II N2215R

Summary

On 13 March 2008 at about 13:40 local time, a Robinson R22 BETA II registered N2215R, operated by Maintenance Services LLC, was involved in an accident near Wilmington, North Carolina, United States. One person was on board and one died. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

13 March 2008 at 13:40

Classification

Accident

Location

Wilmington, North Carolina, United States

Coordinates

34.1247, -77.8983

Aircraft

Robinson R22 BETA II

Registration

N2215R

Category

Helicopter

Engines

1

Operator

Maintenance Services LLC

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Wilmington → Wilmington

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

NYC08FA134

1 person died.

The pilot's failure to maintain proper rotor rpm after a partial loss of engine power.

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

Read the full NTSB narrative

While the helicopter was en route at an estimated 200 hundred feet, a witness on the ground heard the engine "spitting and sputtering." Another witness saw parts “shedding” from the helicopter, then saw it reverse direction and descend until she lost sight of it behind a building. The helicopter subsequently impacted the ground in a vacant lot and erupted into flames. A postflight examination of the engine revealed no mechanical anomalies. The carburetor air temperature gauge was reported to be inoperative and interpolation of a carburetor icing probability chart revealed atmospheric conditions conducive to "serious icing" at glide power. However, the position of the carburetor heat could not be determined and the investigation could not establish the role that carburetor icing may have played in the accident. An examination of the two main rotor blades revealed that each had a section missing, beginning about equidistant from the rotor hub. Both sections were subsequently located away from the main wreckage. Both main rotor blades were also coned upwards from the hub, which, in conjunction with the missing blade sections, was consistent with a low rotor rpm condition. An examination of the tail rotor driveshaft, and the push-pull tube running along it, revealed that they had become entwined, consistent with a “whirl” condition. According to a representative of the manufacturer, such a whirl mode could occur if an overspeed occurs; the manufacturer's maximum operating main rotor rpm limitation is 102%. The event likely began with a partial loss of engine power, followed by the pilot’s delayed response to a low rotor rpm condition, which then resulted in the coning of the main rotor blades and a loss of main rotor blade material.

Quoted verbatim from the NTSB record.