Aerospatiale AS350B accident near Saipan, PO, April 1, 1990
On April 1, 1990 at about 1:55 pm local time, a Aerospatiale AS350B (helicopter), registered N350AP, was destroyed in an accident near Saipan, PO. It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE PARTIAL FAILURE OF A ROTOR SYSTEM COMPONENT FOR UNDETERMINED REASONS.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 1, 1990 · about 1:55 pm local time
- Place
- Saipan, PO
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Aerospatiale AS350B · all AS350Bs on the register
- Registration
- N350AP · no longer on the register · serial 1252
- Damage
- Destroyed
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
THE PILOT AND PAX WERE CRUISING OVER THE PHILIPPINE SEA WHEN THE PILOT FELT AN EXTREME VIBRATION. THE PILOT MADE AN EMERGENCY LANDING IN THE 7-FT SEA. THE PILOT REPORTED THAT PRIOR TO THE HELICOPTER OVERTURNING HE OBSERVED THAT 'ONE OF THE ELASTOMERIC SPHERICAL THRUST BEARINGS WAS COMPLETELY GONE.' THE HELICOPTER SUBSEQUENTLY OVERTURNED, SANK AND HAS NOT BEEN RECOVERED. THE ACFT'S ROTOR SYSTEM HAD PREVIOUSLY BEEN INVOLVED IN A SUDDEN STOPPAGE MISHAP AND HAD THEREAFTER BEEN REPAIRED AND RETURNED TO SERVICE BY OTHER THAN THE CURRENT COMPANY MAINTENANCE PERSONNEL.
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: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane; rotorcraft: helicopter
- Flight time: 6,975 hours in all; 675 in this make and model; 147 in the last 90 days; 89 in the last 30 days; 6,775 as pilot in command; 400 on instruments
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: unk
The aircraft
- Airframe total time: 1,955 hours
- Last inspection: 100-hour inspection, March 31, 1990; 4 hours since
- Maximum gross weight: 4,300 lb
- Seats: 7
- Landing gear: fixed
- Engine: Turbomeca ARRIEL (turboshaft); 0 hours total
- Operator: Micronesian Aviation CORP.
The flight
- Departed from: Koblerville OF
- Destination: Anatahan Island OF
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 020° at 10 knots, gusting 12
- Visibility: 35 statute miles
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.
Other NTSB records under N350AP the same tail number, which may have belonged to a different aircraft at the time
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.