Enstrom F28A N9087

Summary

On 12 January 1997 at about 15:58 local time, a Enstrom F28A registered N9087 was involved in an accident near Saipan Island, Northern Mariana Islands. 5 people were on board and 2 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

12 January 1997 at 15:58

Classification

Accident

Location

Saipan Island, Northern Mariana Islands

Coordinates

Not recorded

Aircraft

Enstrom F28A

Registration

N9087

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Koblerville → Unknown

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

LAX97FA086

2 people died.

loss of engine power due to fuel exhaustion, resulting from improper planning/decision; and the pilot's abrupt handling of the flight controls, while maneuvering to avoid swimmers, which resulted in main rotor blade contact with the tail boom. A related factor was: the presence of swimmers in the emergency landing area, which likely motivated the pilot to alter his approach for a forced/autorotative landing.

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

Read the full NTSB narrative

Shortly before 1510, the pilot started the helicopter's engine, then departed on a sightseeing tour flight around the island with two fare-paying passengers. The operator anticipated the flight would last between 0.5 and 0.7 hrs. For weight considerations, the fuel load had been reduced before takeoff by an estimated 10 gallons bringing the usable quantity to between 16 and 19 gallons, as estimated using a dipstick. About 1558, while cruising off shore & nearly parallel to the shoreline, witnesses observed the helicopter fly past while making sounds like its engine was sputtering, stalling, or cutting in and out. The helicopter's course remained unchanged, & seconds later, other witnesses heard a loud bang sound. The helicopter then entered a rapid descent, & impacted in about 2.5-foot-deep ocean water in front of a hotel where people were swimming. An exam of the wreckage revealed a main rotor blade had impacted & severed the tail rotor drive shaft. No evidence was found indicating the pilot had practiced autorotations in the Enstrom helicopter during the 4.5 months since becoming rotorcraft rated. During the structural airframe and engine examinations, no evidence was found of precipitating mechanical malfunctions. Calculations based on maximum anticipated fuel consumption rates, and approximations for the quantity of fuel on board, revealed fuel exhaustion could occur within 0.1 hour of the flight's duration.

Quoted verbatim from the NTSB record.