Mcdonnell Douglas MD-900 accident near Idaho City, Idaho, November 30, 1998
On November 30, 1998, a Mcdonnell Douglas MD-900 (helicopter), registered N977LF, was substantially damaged in an accident near Idaho City, Idaho. It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). No one was hurt; 4 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot-in-command's not obtaining/maintaining clearance with the unmarked transmission lines. Contributing factors were environmental (dusk) conditions, the transmission lines, and both the pilot-in-command and the ground personnel not identifying the existence of the hazardous condition (high wires).
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- November 30, 1998
- Place
- Idaho City, Idaho · map
- Type
- Accident
- Injuries
- No one was hurt; 4 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Mcdonnell Douglas MD-900
- Registration
- N977LF · no longer on the register · serial 900-00027
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
The McDonnell Douglas MD-900 medevac helicopter was dispatched to a car accident at a site characterized by high terrain and high trees. Prior to landing, the pilot requested information about wires and was advised by ground personnel that 'there were none.' Subsequent to landing, the pilot examined the landing site and proposed departure route for wires, and reportedly observed none. The departure from the site was conducted under dusk to dark night conditions. While climbing out vertically due to the narrow canyon conditions at the site, the helicopter struck unmarked transmission lines approximately 150 feet above ground. The pilot then determined that the helicopter was controllable and displayed no unusual flight characteristics, and chose to proceed to his destination. Post-flight examination revealed crazing of the windscreen and damage to four of the five main rotor blades requiring major repair/replacement.
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: single-engine land; instructor: helicopter; instrument: airplane; rotorcraft: helicopter
- Flight time: 19,275 hours in all; 498 in this make and model; 105 in the last 90 days; 29 in the last 30 days; 19,000 as pilot in command; 750 on instruments
- Medical certificate: Class 1 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 1,752 hours
- Last inspection: continuous airworthiness programme, November 16, 1998; 22 hours since
- Maximum gross weight: 6,250 lb
- Seats: 4
- Landing gear: fixed
- Engine: P&W 206A (turboshaft); 0 hours total
- Operator: Idaho Helicopters, INC.
The flight
- Destination: U56 Boise ID
- Runway 0
Weather at the time
- Light: dusk
- Wind: from 100° at 14 knots
- Visibility: 10 statute miles
- Sky: not recorded; clear
- Temperature: 43°F (6°C), dew point 39°F (4°C)
- Altimeter: 29.00 inHg
- Observation at 1:56 am from BOI
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 3 |
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.