- Date
- March 10, 2015, 15:00 local (23:00 UTC)
- Place
- Palmer, AK
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N86TABell 206B
- Defining event
- Maneuvering-hover: Loss of control in flight
- Weather
- Visual (VMC) · Day
- Status
- Completed · report July 8, 2015
- Report
- Approved by Office Director
- NTSB office
- Alaska Regional Office
- Parties
- FAA
- FAA report
- 20150310003009A
- Case key
- 90851
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 control while hovering at a low altitude, which resulted in an impact with frozen lake ice. Contributing to the accident was the pilot's decision to operate the helicopter from the left seat contrary to the rotorcraft flight manual, and the decision to continue the flight after the initial impact.
Findings · 4
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
The solo helicopter pilot was flying a turbine-powered helicopter, equipped with dual controls, while seated in the left seat. A limitation in the rotorcraft flight manual states, in part: "the minimum flight crew consists of one pilot who shall operate the helicopter from the right crew seat." The N2 governor linear actuator control switch is located on the collective control for the right crew seat only. The pilot reported that flying the helicopter from the left seat and in order to manipulate this control switch, he had to take his left hand off the collective control for the left crew seat, and place it on the left crew seat cyclic control, then take his right hand off the left crew seat cyclic control and place it on the collective control for the right crew seat. The pilot said that while in a 6-foot hover above a frozen lake, he became distracted while adjusting the N2 (rotor) rpm using the linear actuator control switch, and the helicopter became unstable and it began to rapidly descend. He attempted to recover from the unstable condition, but the helicopter's skids struck the ice. After the impact, he was able to recover and regain a stable hover above the ice. Believing that just the helicopter's skids were damaged during the impact, the pilot elected to return to his departure airport, about 19 miles away, where emergency services would be available. During the return flight, as the helicopter climbed to about 50 feet above the ground, all engine power was lost. The pilot entered an emergency autorotation and selected an area of snow-cover as an emergency landing site. The pilot's postaccident inspection of the helicopter revealed that during the initial impact on the frozen lake, the aft landing gear cross-tube assembly had been crushed into the aft portion of the fuselage, which subsequently ruptured the fuel cell, resulting in the loss of all fuel onboard. The pilot stated there were no preaccident mechanical malfunctions or anomalies that would have precluded normal operation.
Factual narrative
The solo helicopter pilot was flying a turbine-powered helicopter, equipped with dual controls, while seated in the left seat. A limitation in the rotorcraft flight manual states, in part: "the minimum flight crew consists of one pilot who shall operate the helicopter from the right crew seat." The N2 governor linear actuator control switch is located on the collective control for the right crew seat only. The pilot reported that flying the helicopter from the left seat and in order to manipulate this control switch, he had to take his left hand off the collective control for the left crew seat, and place it on the left crew seat cyclic control, then take his right hand off the left crew seat cyclic control and place it on the collective control for the right crew seat. The pilot said that while in a 6-foot hover above a frozen lake, he became distracted while adjusting the N2 (rotor) rpm using the linear actuator control switch, and the helicopter became unstable and it began to rapidly descend. He attempted to recover from the unstable condition, but the helicopter's skids struck the ice. After the impact, he was able to recover and regain a stable hover above the ice. Believing that just the helicopter's skids were damaged during the impact, the pilot elected to return to his departure airport, about 19 miles away, where emergency services would be available. During the return flight, as the helicopter climbed to about 50 feet above the ground, all engine power was lost. The pilot entered an emergency autorotation and selected an area of snow-cover as an emergency landing site. The pilot's postaccident inspection of the helicopter revealed that during the initial impact on the frozen lake, the aft landing gear cross-tube assembly had been crushed into the aft portion of the fuselage, which subsequently ruptured the fuel cell, resulting in the loss of all fuel onboard. The pilot stated there were no preaccident mechanical malfunctions or anomalies that would have precluded normal operation.
Aircraft
- Registration
- N86TA
- Reported as
- Bell 206B (B)
- Category
- Helicopter
- Serial number
- 1647
- Built
- 1975
- Airframe hours
- 8,367
- Engine
- Allison 250-C20B, 420 horsepower, turbo shaft
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Operator
- Lee John S
- Registered owner
- Lee John S
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · November 14, 2014
- Departed
- PAAQ · Palmer, AK
- Destination
- PAAQ · Palmer, AK
- Flight plan
- 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
- 69
- Injuries
- None
- Certificates
- Airline transport, Flight instructor
- Airplane ratings
- Single-engine land, Single-engine sea, Multi-engine land
- Instrument ratings
- Helicopter
- Medical
- Class 3, Waiver time limited special
- Last flight review
- September 22, 2014
- Seat
- Left
- Restraint
- 4-point
- Flight hours
- 14,190 total · 1,200 in this make and model · 12,000 as pilot in command · 50 in the last 90 days · 15 in the last 30 days
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 160° at 4 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 16 °F, dew point -4 °F
- Altimeter
- 30.14 inHg
- Observed at
- PAAQ, 19 nm away
Docket · 2
The files NTSB released with the investigation on June 24, 2015, on NTSB’s docket system: statements, records, photos and specialists’ reports. 968 KB 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 N86TA · 1
Matched to the same aircraft by N-number and date.