Bell UH-1H accident near Silverton, Colorado, September 6, 1999
On September 6, 1999 at about 2:30 pm local time, a Bell UH-1H (helicopter), registered N4085L, was substantially damaged in an accident near Silverton, Colorado. It was an other work-use flight under external-load helicopter rules (Part 133). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The total loss of engine power for undetermined reasons. A factor was the lack of suitable 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 6, 1999 · about 2:30 pm local time
- Place
- Silverton, Colorado · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell UH-1H · all UH-1Hs on the register
- Registration
- N4085L · no longer on the register · serial 68-15655
- Damage
- Substantial damage
- Flight
- Other work-use flight · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
The pilot said this was his first trip of the morning, and he was transporting approximately 300 pounds of construction materials. He said that the load was on the ground and he was hovering while ground personnel disconnected the cargo net. He said that one of the ground team radioed him and reported that 'fire and smoke was coming from your tail pipe.' The pilot said that he noticed that the rotor rpm warning light was on, and the engine out lights and horns had been activated. He lowered the collective and autorotated to the ground, but the main rotors impacted terrain. The aircraft records indicate that the engine came from a civilian overhaul facility, and was installed in N4085L approximately 21 hours prior to the accident. The Colorado Department of Minerals and Mines reported the mine entrance elevation was 11,500 feet. The density altitude was calculated to be 13,000 feet.
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, private
- Ratings: single-engine land; instructor: helicopter; rotorcraft: helicopter
- Flight time: 10,500 hours in all; 5,000 in this make and model; 16 in the last 30 days; 11,000 as pilot in command; 2,000 on instruments
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 3,854 hours
- Last inspection: annual inspection, October 12, 1999
- Landing gear: fixed
- Engine: Lycoming T53-L-13 (turboshaft); 0 hours total
The flight
- Departed from: NONE at 2:10 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 130° at 8 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 61°F (16°C), dew point 45°F (7°C)
- Altimeter: 30.00 inHg
- Observation at 2:53 pm from MTJ, 40 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.
Other NTSB records under N4085L 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.