Aerospatiale AS350BA accident near Burbank, California, June 6, 1998
On June 6, 1998 at about 7:25 am local time, a Aerospatiale AS350BA (helicopter), registered N31621, was substantially damaged in an accident near Burbank, California. It was a positioning flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The separation of the tail rotor pitch link due to a fatigue fracture, which resulted in the separation of the tailboom.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 6, 1998 · about 7:25 am local time
- Place
- Burbank, California
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Aerospatiale AS350BA · all AS350BAs on the register
- Registration
- N31621 · no longer on the register · serial 2130
- Damage
- Substantial damage
- Flight
- Positioning flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot felt a 'violent vibration' and the helicopter began to pitch and yaw. About 5 seconds after the vibration started, the tail rotor gearbox chip light became illuminated. The pilot made a normal approach to a rooftop parking structure and landed. The last 3 feet of the tail boom had separated 360 degrees in circumference. Examination of the tail rotor system revealed one pitch change link disconnected due to a fatigue fracture, which emanated from multiple origins at the inside diameter surface of the loop that is in contact with the bearing assembly. The scrim cloth for the bearing assembly raceway was missing, and the bearing outer raceway contained wear damage approximately 180 degrees around its circumference. A maximum of 0.008 inches of play is allowed in the radial direction between the ball and the pitch change link assembly; however, no limit is specified for the axial direction. The pilot reported that he completed a required daily inspection of the aircraft the day before the accident and observed no play in either tail rotor pitch link, nor did he see any cracks. He also reported that he performed a preflight before takeoff on the accident flight and did not note any discrepancies at that time.
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: airline transport pilot, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: helicopter; instrument: airplane; rotorcraft: helicopter
- Flight time: 9,000 hours in all; 50 in this make and model; 40 in the last 90 days; 15 in the last 30 days
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 1,014 hours
- Last inspection: approved inspection programme, April 15, 1998; 65 hours since
- Maximum gross weight: 4,630 lb
- Seats: 6
- Landing gear: fixed
- Engine: Turbomeca AERRIEL 1B (turboshaft); 0 hours total
The flight
- Departed from: Lake Arrowhead CA
- Destination: VNY Van Nuys CA
- Flight plan: none
- Runway 0
Weather at the time
- Light: night, dark
- Wind: from 090° at 5 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 61°F (16°C), dew point 54°F (12°C)
- Altimeter: 29.00 inHg
- Observation at 6:53 am from BUR, 5 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 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.