PIPER L 21B near Big Timber, MT — 2017-07-08
- Date
- 2017-07-08
- Location
- Big Timber, MT, USA
- Aircraft
- PIPER L 21B
- Registration
- N99031
- Category
- Airplane
- Highest injury
- Serious
- Fatalities
- 0
- Phase of flight
- Maneuvering
Probable cause
The pilot's decision to fly at low altitude in the vicinity of power lines, which resulted in a wire strike.
NTSB narrative
The private pilot reported that, after departure, he followed the course of a river at an altitude about level with the treetops. Although the pilot was aware of powerlines in the area, he did not see them before the airplane collided with the powerlines about 90 ft above ground level. The airplane subsequently nosed down and impacted the river, resulting in substantial damage. According to the manager of the airport from which the airplane departed, it is not uncommon for pilots to fly at low altitudes in that area to avoid turbulent air in the summertime. He further reported that the power lines were not equipped with aerial marker balls. Following the accident, the airport manager agreed to install signage in the fixed base operator at the airport to caution pilots of the presence of power lines in that area.
Analysis
- Primary failure mode
- Human factors
- First missed decision gate
- Pilot could have avoided flying at tree level near known power lines.
NTSB coding
Evidence available
- Photos
- 5 docket documents
Docket documents5
Related mishaps
- CESSNA A188B
2026-07-29 · Algona, IA
- ROBINSON HELICOPTER COMPANY R44
2026-04-17 · Mount Blanco, TX
- ROBINSON HELICOPTER R22 BETA
2025-08-03 · Taylor, TX
- ROBINSON HELICOPTER COMPANY R44 II
2025-08-03 · Ponderosa Pines, MT
- AIR TRACTOR INC AT-502B
2025-06-23 · Charleston, MO
- PIPER PA-36-375
2025-06-19 · Huron, SD