Eurocopter AS-350-B2 accident near Cascade, Colorado, September 8, 1994
On September 8, 1994 at about 4:43 pm local time, a Eurocopter AS-350-B2 (helicopter), registered N99TV, was destroyed in an accident near Cascade, Colorado. It was a business flight under general aviation rules (Part 91). 2 people had minor injuries; 1 other was unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A POWER LOSS DUE TO CONTAMINATED FUEL FROM AN UNKNOWN SOURCE THAT CLOGGED THE FUEL FILTER AND INTERNALLY DAMAGED THE FUEL CONTROL UNIT. A FACTOR WAS UNSUITABLE TERRAIN FOR A FORCED LANDING.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 8, 1994 · about 4:43 pm local time
- Place
- Cascade, Colorado · map
- Type
- Accident
- Injuries
- 2 people had minor injuries; 1 other was unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Eurocopter AS-350-B2 · all AS-350-B2s on the register
- Registration
- N99TV · registry record · serial 2666
- Damage
- Destroyed
- Flight
- Business flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
SHORTLY AFTER TAKEOFF FROM ATOP PIKES PEAK, THE ENGINE LOST POWER AND THE PILOT AUTOROTATED STRAIGHT AHEAD. THE HELICOPTER COLLIDED WITH TREES AND ROLLED OVER. FUEL SAMPLES CONTAINED VISIBLE CONTAMINANTS AND THE FUEL CONTROL UNIT (FCU) WAS UNABLE TO ATTAIN TARGET FUEL FLOW DURING POST ACCIDENT TESTING. THE CONTAMINANTS WERE IDENTIFIED AS FILTER MATERIAL AND PARTICLES OF METAL, GLASS, SAND, AND PLASTIC. METALLIC PARTICLES WERE IDENTIFIED AS BEING COPPER, IRON, NICKEL, AND CHROMIUM. FCU DISASSEMBLY REVEALED A CLOGGED AMPLIFIER PISTON FILTER, A SCORED ISOCHRONOUS PISTON, AND A COLLAPSED TEMPERATURE COMPENSATOR. ACCORDING TO THE ENGINE MANUFACTURER, THE FUEL CONTAMINANTS COULD DISTURB FCU OPERATION AND THE SCORED PISTON WAS 'EVIDENCE OF AN OPERATION WITH POLLUTED FUEL.' THE SOURCE OF CONTAMINANTS WAS NOT DETERMINED. NO REPORTS OF FUEL CONTAMINATION WERE RECEIVED FROM OTHER PILOTS USING THE SAME FUEL VENDOR.
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, flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: helicopter; instructor: instrument helicopter; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 16,715 hours in all; 830 in this make and model; 161 in the last 90 days; 73 in the last 30 days; 16,500 as pilot in command; 4,235 on instruments
- Medical certificate: Class 1 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 840 hours
- Last inspection: approved inspection programme; 39 hours since
- Maximum gross weight: 4,961 lb
- Seats: 4
- Landing gear: fixed
- Engine: Turbomeca ARRIEL 1D1 (turboshaft); 0 hours total
The flight
- Destination: CO88 Denver CO
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 75°F (24°C), dew point 43°F (6°C)
- Altimeter: 30.00 inHg
- Observation at 4:50 pm from COS, 15 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 1 | 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 N99TV 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.