CircumFlightN3623Z Hughes 269C accident
NTSB WPR11LA325 · 2011-07-12 · Wenatchee, WA
Docket — crew, injuries and powerplant
Summary
The pilot reported that, during a low altitude and slow airspeed flight to dry cherry trees, the engine lost power, and the helicopter subsequently settled into the trees. However, when the helicopter came to rest, the engine was still operating, and he had shut it down. During postaccident examination of the engine and airframe, no evidence of a mechanical malfunction or failure was found that would have precluded normal operation of the engine or flight controls. It is likely that the pilot did not maintain control of the helicopter while hovering out of ground effect at low altitude and experienced a settling with power event.
Full narrative
HISTORY OF FLIGHT
On July 12, 2011, about 0905 Pacific daylight time (PDT), a Hughes 269C, N3623Z, collided with trees near Wenatchee, Washington. Applebee Aviation, Inc., was operating the helicopter under the provisions of 14 Code of Federal Regulations (CFR) Part 91 for the purpose of drying cherry trees. The certificated commercial pilot and one passenger sustained minor injuries. The helicopter sustained substantial damage to the tail boom and to the main rotor blades. The local flight departed Wenatchee about 0845. Visual meteorological conditions prevailed, and no flight plan had been filed.
The pilot reported that he was flying at a low altitude and slow airspeed over cherry trees to dry them when the engine experienced a loss of power. Due to the low altitude, the helicopter settled into the trees. After the accident, the pilot reported that the engine was still operating and he had to shut it down.
During the postaccident examination of the engine and airframe, no evidence of a mechanical malfunction or failure was found that would have precluded normal operation with the engine or flight controls of the helicopter.
ADDITIONAL INFORMATION
Vortex Ring State (Settling With Power)
According to the FAA Rotorcraft Flying Handbook, "Vortex ring state describes an aerodynamic condition where a helicopter may be in a vertical descent with up to maximum power applied, and little or no cyclic authority. The term 'settling with power' comes from the fact that the helicopter keeps settling even though full engine power is applied."
Probable cause
The pilot's failure to maintain control while hovering out of ground effect at low altitude, which resulted in the helicopter settling into trees. The National Transportation Safety Board determined the probable cause of this accident.
Circumstances
- Event type
- Accident
- Highest injury
- Minor
- Weather conditions
- Visual Meteorological Cond
- Light condition
- Day
- Sky condition
- NONE
- Ceiling (ft)
- 0
- Visibility (sm)
- 10
- Wind direction
- 320
- Wind speed (kt)
- 8
- Temperature (F)
- 64
- Distance from field
- 0.0
Aircraft
| Registration | Make | Model | Damage | FAR part |
|---|---|---|---|---|
| N3623Z | HUGHES | 269C | SUBS | 091 |
Sequence of events
| # | Occurrence | Phase |
|---|---|---|
| 1 | Maneuvering-low-alt flying Loss of control in flight defining | Climb |
| 2 | Maneuvering-low-alt flying Settling with power/vortex ring state | Climb |
| 3 | Uncontrolled descent Collision with terr/obj (non-CFIT) | Descent |
Findings
| Finding | |
|---|---|
| Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot | cause |
| Aircraft-Aircraft oper/perf/capability-Performance/control parameters-(general)-Not attained/maintained | cause |