British Aerospace BAE 146-200A incident near Aspen, Colorado, February 12, 1999
On February 12, 1999 at about 1:50 am local time, a British Aerospace BAE 146-200A, registered N608AW, suffered minor damage in an incident near Aspen, Colorado. It was a flight of an unrecorded kind under scheduled airline rules (Part 121). No one was hurt; 88 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The inadequate maintenance overhaul of the number four turbine disc by the manufacturer. A factor was the turbine blade's failure due to high cycle fatigue fracture.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 12, 1999 · about 1:50 am local time
- Place
- Aspen, Colorado · map
- Type
- Incident
- Injuries
- No one was hurt; 88 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- British Aerospace BAE 146-200A BAE 146-20 · all BAE 146-200As on the register
- Registration
- N608AW · no longer on the register · serial E2049
- Damage
- Minor damage
- Flight
- Flight of an unrecorded kind · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
The airplane experienced an uncontained number 4 engine failure during climb to cruise altitude. Examination of the engine revealed that the number 4 turbine disc had all its blades separated just above the blade platform except 1, which separated just below the blade platform. According to maintenance records, the number 4 turbine disc assembly was installed 22.5 hours or 22 cycles prior to this event. The manufacturer of the turbine disc said that the wheel was new; however, all 60 of the blades had seen previous use. A high-cycle fatigue crack was found in the one blade which had separated below the blade platform. The metallurgist noted that the fatigue crack originated from a fretting damage mark located at the fir-tree portion. The manufacturer reported that 9 blade retention pins, which were used to prevent blade radial movement, did not meet the requirement of no more than 0.005 inch clearance between pen head and wheel. They further reported that blade stress concentration was induced by the wheel broach slots sharp edges.
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
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instrument: airplane
- Flight time: 21,500 hours in all; 4,687 in this make and model; 216 in the last 90 days; 68 in the last 30 days
- Medical certificate: Class 1 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 24,544 hours
- Last inspection: continuous airworthiness programme, February 9, 1999; 23 hours since
- Maximum gross weight: 89,500 lb
- Seats: 90
- Landing gear: retractable
- Engine: Lycoming ALF502R-5 (turbojet); 0 hours total
The flight
- Departed from: ASE at 1:37 am
- Destination: DEN Denver CO
- Flight plan: IFR
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: dusk
- Wind: from 170° at 8 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 18°F (-8°C), dew point 0°F (-18°C)
- Altimeter: 30.00 inHg
- Observation at 1:53 am from DEN, 90 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 4 | |||
| Passengers | 84 |
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 N608AW the same tail number, which may have belonged to a different aircraft at the time
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number DEN99IA038.