Sikorsky S-61A N318Y

Summary

On 26 March 2002 at about 23:38 local time, a Sikorsky S-61A registered N318Y was involved in an accident near Lakehead, California, United States. 2 people were on board and one died, one was seriously injured. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

26 March 2002 at 23:38

Classification

Accident

Location

Lakehead, California, United States

Coordinates

41.0411, -122.1944

Aircraft

Sikorsky S-61A

Registration

N318Y

Category

Helicopter

Engines

2

Operator

Not recorded

Operating rule

Part 133: Rotorcraft Ext. Load

Purpose of flight

Other Work Use

Phase of flight

Not recorded

Route

Lakehead → Unknown

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

LAX02FA116

1 person died.

A loss of engine power for undetermined reasons, and the flight crew's failure to maintain rotor rpm following a loss of engine power while maneuvering.

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

Read the full NTSB narrative

The twin-engine helicopter impacted trees and terrain following a likely loss of power in the left engine while maneuvering. According to one witness, as the helicopter overflew his position, he observed the main rotor blades rotating very slowly to the point where they were coning and each blade could be viewed individually. This witness observed a tan smoke emanating from the transmission area. The helicopter then "fell like a rock," and impacted the ground. The witness indicated he heard the engines surging when he reached the accident site. Another witness did not hear any engine noise as the helicopter passed overhead. A post crash fire consumed the cabin, main transmission case, and, heavily damaged both engines. A post-accident examination of the helicopter revealed the main rotor and tail rotor blades sustained little to no leading edge damage though the helicopter fell through 150-foot pine trees. The number 1 engine displayed no rotational damage to its internal components. The number 2 engine sustained heat and tip rub damage to the 1st and 2nd stage gas turbine blades in a manner that suggested the damage occurred while the rotors were rotating. Numerous components from each engine were completely destroyed by the post-accident fire and could not be examined. The main rotor transmission case was nearly burned away. The exposed transmission gears displayed no signs of pre-existing anomalies; however, complete continuity of the transmission could not be established due to thermal damage. The number 1 and number 2 input free wheeling units were examined and displayed no signs of improper operation. The cockpit sustained severe fire damage; however, the left side triple tachometer and both left and right side torque indicators were examined. The torque indicators both displayed the number 1 engine torque at 13 percent, while the number 2 engine torque indication was only available on the left torque indicator, which displayed a number 2 engine torque reading of 140 percent.

Quoted verbatim from the NTSB record.