Sikorsky S-76C N317MY

Summary

On 17 June 2005 at about 20:38 local time, a Sikorsky S-76C registered N317MY was involved in an accident near New York, New York, United States. 8 people were on board and one was seriously injured, 7 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

17 June 2005 at 20:38

Classification

Accident

Location

New York, New York, United States

Nearest airport

East 34TH Street (6N5)

Coordinates

40.7433, -73.9717

Aircraft

Sikorsky S-76C

Registration

N317MY

Category

Helicopter

Engines

2

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Executive/Corporate

Phase of flight

Not recorded

Route

New York → Wilmington

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

IAD05MA078

1 person was seriously injured.

An inadvertent encounter with a left quartering tailwind. Factors in the accident were settling with power, the high gross weight of the helicopter, and the crew's failure to accurately assess the winds in the area.

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

Read the full NTSB narrative

While facing west on a crowded urban heliport on the leeward side of tall buildings that blocked westerly winds of 15 knots gusting to 23 knots, the pilot executed a rearward takeoff in calm winds slightly above the maximum gross weight of the helicopter. Once clear of the heliport and while out-of ground-effect, the pilot executed a right pedal turn for a north departure over the water, and lowered the nose to initiate an acceleration. Simultaneously the helicopter encountered a left quartering tailwind that was originally blocked by the tall buildings. The helicopter began to settle, and contacted the water. While executing the right pedal turn to transition to forward flight, the pilot noticed an audible "degrading" of the rotor rpm, and the N1 in the "yellow." During interviews with the flight crew, neither pilot could articulate what the maximum allowable gross weight was for the environmental conditions. Each pilot could only say the helicopter was "good" for the takeoff. According to performance data, the maximum gross weight for takeoff was 11,700 pounds, but the data didn't provide a means for calculating power margins. Prior to flying into the heliport on the day of the accident, the pilots had the helicopter was fueled to capacity. This decision was based on picking up five passengers instead of the six that actually boarded. Aware of the additional passenger and without conducting any additional performance planning, the pilot attempted the departure. Prior to contacting the water, the crew experienced uncommanded pitch and roll oscillations, and high levels of vibration consistent with settling with power. Examination of the wreckage, post accident engine runs, and testing of the digital engine control units revealed no preimpact anomalies.

Quoted verbatim from the NTSB record.