- Date
- October 30, 2011, 16:20 local (22:20 UTC)
- Place
- Florence, MT
- Injuries
- 3 uninjured
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N7276GCessna 172K
- Defining event
- Maneuvering-low-alt flying: Low altitude operation/event
- Weather
- Visual (VMC) · Day
- Status
- Completed · report January 18, 2012
- Report
- Approved by Office Director
- NTSB office
- Western Pacific Region
- Parties
- FAA FSDO
- FAA report
- 20111030024669A
- Case key
- 82215
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
The pilot's failure to maintain clearance from a power line during a low-level flight along a river. Contributing to the accident was the pilot's decision to fly at a low altitude.
Findings · 3
NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.
Sequence of events
The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.
Analysis
After a series of takeoffs and landings at several nearby airports, the pilot was returning to his home airport and descended to a low level to follow a river. The pilot reported that the conditions were turbulent for most of the day but that, during that low-altitude leg, the airplane seemed to perform abnormally. While still airborne, a passenger observed that the brake line that was attached to the right main landing gear strut was severed. As a result, the pilot conducted a precautionary landing at a nearby airport. The pilot and passengers observed multiple damage sites on the airplane but, since no one was present at that airport, they reboarded and departed for the home airport where they landed uneventfully. A postaccident investigation revealed that the airplane struck and severed one of several electrical power lines that spanned the river. The wire height at mid river was about 30 to 40 feet above the water. The propeller, cowling, exhaust stack, right wing (multiple places), right wing strut, right main gear brake line, right landing gear wheel fairing, right fuselage, and vertical stabilizer were damaged by the wire strike, and the rear window was punctured. The pilot stated that he did not see any wires and that he was not aware of the wire strike until he examined the airplane after the precautionary landing. Neither the pilot nor the passengers incurred any injuries.
Factual narrative
The pilot departed, conducted a touch-and-go at one airport, landed at another, and then flew north to a third airport, where another touch-and-go was conducted. The airplane then headed south towards the home airport, and the pilot descended to low level and followed a river for a portion of that flight leg. The pilot reported that the conditions were turbulent for most of the day, but during that low-altitude leg, the airplane behavior seemed abnormal. While still airborne, a passenger observed that the brake line that was attached to the right main landing gear strut was severed. As a result, the pilot conducted a precautionary landing at a nearby airport. The pilot and passengers observed multiple damage sites on the airplane, but since no one was present at that airport, they reboarded and departed for the home airport, where an uneventful landing was made. Investigation revealed that the airplane struck and severed one of several electrical power lines, which spanned the river. Those lines were strung between two poles, one on each side of the river. Both poles were set back from the river edge, and the west pole was situated in a loose stand of trees. The approximate wire span was 464 feet, and the wire height at mid river was approximately 30 to 40 feet above the water. Airplane damage from the wire strike included the propeller, cowling, exhaust stack, right wing (multiple places), right wing strut, right main gear brake line, right landing gear wheel fairing, right fuselage, and vertical stabilizer. In addition, the rear window was punctured. The pilot stated that he did not see any wires, and that he was not aware of the wire strike until he examined the airplane after the precautionary landing. Neither the pilot nor the passengers incurred any injuries.
Aircraft
- Registration
- N7276G
- Reported as
- Cessna 172K (K)
- Category
- Airplane
- Serial number
- 17258976
- Airframe hours
- 3,553
- Engine
- Lycoming O-320, 150 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Operator
- North Star Aviation
- Registered owner
- North Star Aviation
- Airworthiness certificate
- Standard, Normal
- Last inspection
- 100 hour · September 29, 2011
- Departed
- MSO · Missoula, MT
- Destination
- 6S5 · Hamilton, MT
- Airport
- 6S5 · Ravalli County
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 38
- Injuries
- None
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Medical
- Class 3, Without waivers/limitations
- Last flight review
- January 4, 2010
- Seat
- Left
- Flight hours
- 126 total · 20 in this make and model · 89 as pilot in command · 6 in the last 90 days · 3 in the last 30 days
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 110° at 3 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 54 °F, dew point 30 °F
- Altimeter
- 30.06 inHg
- Observed at
- MSO, 20 nm away
Docket · 13
The files NTSB released with the investigation on December 6, 2011, on NTSB’s docket system: statements, records, photos and specialists’ reports. 6.4 MB in all.
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.