CircumFlightN7452F Hughes 269C accident
NTSB SEA04LA011 · 2003-10-26 · Hillsboro, OR · near 7S3
Docket — crew, injuries and powerplant
Summary
The flight instructor initiated a demonstration of a low altitude auto-rotation while moving forward in a hover at a "brisk walk." The planned touchdown site was to a grassy area slightly east of the runway environment and upon touchdown, the helicopter's skids encountered soft terrain and dug in and the helicopter rocked forward up onto the toes of the skids. Immediately thereafter, the main rotor blades contacted the ground and the helicopter came to rest on the forward skid toes and the main rotor mast. The instructor reported that there was no mechanical malfunction with the helicopter at the time of the event and the terrain at the selected site for the auto rotation was soft.
Full narrative
On October 26, 2003, approximately 1215 Pacific standard time, a Hughes 269C helicopter, N7452F, registered to and being operated/flown by a commercially rated flight instructor, sustained substantial damage during a nose down event following a low altitude auto-rotation landing at the Stark's Twin Oaks Airpark, Hillsboro (7S3), Oregon. Both the flight instructor and the pilot under instruction were uninjured. Visual meteorological conditions existed and no flight plan had been filed. The flight, which was instructional, was operated under 14CFR91, and originated from the Hillsboro airport (HIO), Hillsboro, Oregon, at 1145 on the morning of the accident.
The instructor reported to an inspector assigned to the Hillsboro Federal Aviation Administration's Flight Standards District Office that he was in control of the helicopter, which was moving forward in a hover at a "brisk walk." He initiated a demonstration of an auto-rotation while in the forward hover to a grassy area slightly east of the runway environment and upon touchdown, the helicopter's skids encountered soft terrain and dug in and the helicopter rocked forward up onto the toes of the skids. Immediately thereafter, the main rotor blades contacted the ground and the helicopter came to rest on the forward skid toes and the main rotor mast. The instructor reported that there was no mechanical malfunction with the helicopter at the time of the event and the terrain at the selected site for the auto-rotation was soft.
Probable cause
The pilot's selection of unsuitable terrain for a practice auto rotation landing. A contributing factor was the soft terrain. The National Transportation Safety Board determined the probable cause of this accident.
Circumstances
- Event type
- Accident
- Highest injury
- None
- Weather conditions
- Visual Meteorological Cond
- Light condition
- Day
- Sky condition
- NONE
- Ceiling (ft)
- 0
- Visibility (sm)
- 10
- Wind direction
- 0
- Temperature (F)
- 66
- Nearest airport
- Stark's Twin Oaks Airpark
- Distance from field
- 0.0
- Airport elevation
- 170
Aircraft
| Registration | Make | Model | Damage | FAR part |
|---|---|---|---|---|
| N7452F | Hughes | 269C | SUBS | 091 |
Sequence of events
| # | Occurrence | Phase |
|---|---|---|
| 1 | 290 | Cruise |
Findings
| Finding | |
|---|---|
| 19200 | factor |
| 24029 | cause |