Hughes 369D accident near Milolii, Hawaii, February 21, 1997
On February 21, 1997 at about 7:09 pm local time, a Hughes 369D (helicopter), registered N505RM, was substantially damaged in an accident near Milolii, Hawaii. It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). 3 people were seriously injured and 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
failure of the tail rotor for undetermined reason(s), resulting in tail rotor imbalance, separation of the tail rotor, and an autorotative landing on rough terrain with high vegetation. The lack of suitable terrain for a forced landing was a related factor.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 21, 1997 · about 7:09 pm local time
- Place
- Milolii, Hawaii · map
- Type
- Accident
- Injuries
- 3 people were seriously injured and 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Hughes 369D HU-369-D · all 369Ds on the register
- Registration
- N505RM · registry record · serial 1080358D
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
The purpose of the flight was to transport state employees to a nearby work site. The pilot took off, climbed to about 400 feet msl, and accelerated to 90 knots. The first minute of flight was routine, and the pilot did not indicate he was experiencing any malfunctions. Suddenly, a loud bang was heard which was followed by a slight shudder in the tail rotor pedals. A passenger reported observing pieces of the tail rotor blades flying past the left side of the helicopter. The pilot applied pressure to the tail rotor pedals, but no response was evident. The pilot autorotated to a landing on rough terrain covered with vegetation. The helicopter was recovered and examined. No evidence of mechanical problems was found. The tail rotor blade assembly was not located. Prior to the flight, the helicopter's doors had been removed. Also, 2 days earlier, company maintenance personnel had replaced one of the two tail rotor pitch change links due to excessive wear in its rod end bearing.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: commercial pilot
- Ratings: instructor: helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 8,575 hours in all; 775 in this make and model; 70 in the last 90 days; 25 in the last 30 days; 8,395 as pilot in command
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 7,974 hours
- Last inspection: 100-hour inspection, January 20, 1997; 80 hours since
- Maximum gross weight: 3,000 lb
- Seats: 5
- Landing gear: fixed
- Engine: Allison 250-C20B (turboshaft); 0 hours total
The flight
- Departed from: HI at 6:50 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 200° at 5 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 79°F (26°C), dew point 66°F (19°C)
- Altimeter: 30.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 2 | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.