Bell UH-1B accident near Wrangell, Alaska, May 5, 1999
On May 5, 1999 at about 11:00 pm local time, a Bell UH-1B (helicopter), registered N97HM, was involved in an accident near Wrangell, Alaska. It was a public-use flight under external-load helicopter rules (Part 133). No one was hurt; 2 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 failure to maintain sufficient distance from a transmission wire, arcing of the transmission wire, the failure of company personnel to utilize a nonconducting cable, and an inadequate procedure utilized by the construction project manager to ensure adequate fault protection on an energized transmission wire. Factors in the accident were a failure of the helicopter operator to maintain sufficient standards, including flight and ground crew coordination, and a failure to maintain radio communication between the pilot and ground crew.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 5, 1999 · about 11:00 pm local time
- Place
- Wrangell, Alaska · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell UH-1B · all UH-1Bs on the register
- Registration
- N97HM · registry record · serial 62-2034
- Damage
- Not recorded
- Flight
- Public-use flight · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
A restricted category Bell UH-1B helicopter was hovering near high voltage wires at a construction site, performing external load lift operations with a 110 feet long steel cable. The construction project was under the direction of the Alaska Energy Authority, a State of Alaska corporation. The State of Alaska construction project manager reported the electrical wires were energized, and the wires were configured to de-energize if shorted. The pilot had extensive external load experience, but had about 1 hour in the accident helicopter make and model. He said he was not aware the electrical wires were energized. The chief pilot was occupying the right seat, and said he was providing 'guidance' during the flight. The chief pilot said he was aware the wires were hot. Just after the long line was hooked to a load of steel beams on the ground, the cable touched the overhead electrical wire, and electrocuted one ground member standing on the load. The construction project operations manager said that the electrical short, caused when the cable touched the wire, was insufficient to trip the electrical power off. The helicopter company's external load manual includes the following: 'The chief pilot will brief all involved personnel concerning procedures for each operation; the flight crew consists (normally) of one pilot; the use of a hand signalman, separate from the ground crew, shall be assigned no other duties during the operation; the pilot may elect to use a continuous visual observation method, wherein he is directly observing the load by looking out the window, out the door, or by use of mirrors. In this case, release and/or signalmen need not be utilized.' The manual also includes: 'Radio contact between the pilot and the hook-up man is highly desirable, and the presence of a radioman in no way alleviates the need for the hand signalman. A signalman should be present at all times in the event of a radio failure. If the pilot is able to observe the hook-up operation by using a skid-mounted mirror, and VHF two-way radio communications are maintained between the pilot and the hook-up man, a signalman is not required.' During the accident, direct radio communication between the ground crew and the pilot was not maintained, and a signalman was not utilized.
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: commercial pilot
- Ratings: rotorcraft: helicopter
- Flight time: 18,000 hours in all; 2 in this make and model
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 6,942 hours
- Last inspection: 100-hour inspection, December 31, 1998; 64 hours since
- Maximum gross weight: 8,500 lb
- Seats: 7
- Landing gear: fixed
- Engine: Lycoming T53L-13 (turboshaft); 0 hours total
The flight
- Departed from: WRG AK at 5:30 pm
- Flight plan: none
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 090° at 6 knots, gusting 12
- Visibility: 10 statute miles
- Sky: overcast at 3,000 ft; not recorded
- Temperature: 34°F (1°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 |
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.