- Date
- December 21, 2011, 16:15 local (21:15 UTC)
- Place
- Fall Branch, TN
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Enroute
- Aircraft
- N500TNHughes 369D
- Defining event
- Enroute: VFR encounter with IMC
- Weather
- Instrument (IMC) · Day
- Status
- Completed · report March 27, 2012
- Report
- Approved by Office Director
- NTSB office
- Eastern Region Aviation
- Parties
- FAA / FSDO
- FAA report
- 20111221029959A
- Case key
- 82553
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 improper decision to continue a visual flight into instrument meteorological conditions, which resulted in a wire strike.
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
Prior to departure on a positioning flight, the pilot checked the weather and determined that visual meteorological conditions existed at both his departure and destination airports. However, while the pilot was following a highway in cruise flight at 400 feet above ground level, the ceiling rapidly became lower, and the pilot encountered instrument meteorological conditions. Moments later, while cruising at an airspeed of 65 knots, the pilot saw marker balls, which indicated that power lines were directly in front of the helicopter. The pilot lowered the collective and entered a right diving turn in order to avoid the wires, but one of the main rotor blades made contact. The rotor speed remained within limits, but the helicopter began to vibrate, so the pilot decided to land in a nearby field. Postaccident examination of the helicopter revealed that the main rotor blade that had made contact with the power line was substantially damaged.
Factual narrative
Prior to departure on a positioning flight, the pilot of the helicopter checked the weather and determined that visual meteorological conditions existed at both his departure and destination airports. However, while in cruise flight at 400 feet above ground level while following a highway, the ceiling rapidly became lower, and the pilot encountered instrument meteorological conditions. Moments later at an airspeed of 65 knots, marker balls appeared which indicated that power lines were directly in front of him. He lowered the collective and entered a right diving turn in order to avoid the wires but one of his main rotor blades made contact with a power line. The rotor speed remained within limits but the helicopter began to vibrate. As a result, the pilot decided to land in a nearby field. Post accident examination of the helicopter revealed that the main rotor blade that had made contact with the power line was substantially damaged.
Aircraft
- Registration
- N500TN
- Reported as
- Hughes 369D
- Category
- Helicopter
- Serial number
- 590521D
- Airframe hours
- 14,193
- Engine
- Rolls-Royce 250-C20R/2, 450 horsepower, turbo shaft
- Damage
- Substantial damage
- Flight
- Aerial observation · Part 91
- Operator
- Air 2 LLC
- Registered owner
- Air 2 LLC
- Airworthiness certificate
- Standard, Normal
- Last inspection
- 100 hour · December 5, 2011
- Departed
- DXX · Knoxville, TN
- Destination
- KTRI · Blountville, TN
- Flight plan
- Company VFR
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 32
- Injuries
- None
- Certificates
- Commercial, Flight instructor
- Instrument ratings
- Helicopter
- Medical
- Class 2, Without waivers/limitations
- Last flight review
- January 21, 2011
- Seat
- Left
- Flight hours
- 2,337 total · 400 in this make and model · 2,387 as pilot in command · 220 in the last 90 days · 70 in the last 30 days · 7 in the last 24 hours
Weather
- Conditions
- Instrument (IMC) · Day
- Wind
- 230° at 10 knots
- Visibility
- 1 statute miles
- Lowest ceiling
- 400 ft overcast
- Temperature
- 61 °F, dew point 57 °F
- Altimeter
- 29.89 inHg
Docket · 9
The files NTSB released with the investigation on January 31, 2012, on NTSB’s docket system: statements, records, photos and specialists’ reports. 17.4 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.
Other investigations on N500TN · 1
Matched to the same aircraft by N-number and date.