Robinson Helicopter R22 BETA accident near Forest Grove, Oregon, September 20, 2009
On September 20, 2009 at about 8:09 pm local time, a Robinson Helicopter R22 BETA, registered N956SH, was substantially damaged in an accident near Forest Grove, Oregon (Hillsboro airport). It was an instructional flight under general aviation rules (Part 91). 2 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The flight crew’s failure to maintain adequate main rotor speed while maneuvering, which resulted in a main rotor blade stall and an uncontrolled descent into terrain.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 20, 2009 · about 8:09 pm local time
- Place
- Forest Grove, Oregon · Hillsboro · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Robinson Helicopter R22 BETA · all R22 BETAs on the register
- Registration
- N956SH · no longer on the register · serial 0956
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot under instruction was preparing for a certified flight instructor (CFI) check ride and was in the left seat. The CFI was in the right seat, and the two airmen were going to practice autorotations with power recoveries. A witness with helicopter experience observed several uneventful autorotations and then stopped watching; another witness heard a bang. The witnesses then observed the helicopter descending upright with the left skid low. Investigators examined the wreckage and observed signatures indicating that the engine and main rotor blades were rotating at a low speed at impact. The main rotor blades were also coned upward, which is indicative of a low main rotor rpm state. A safety notice issued by the helicopter's manufacturer notes that main rotor blade stall due to low main rotor rpm causes a high percentage of helicopter accidents. It points out that the stall causes the main rotor rpm to rapidly decrease, and leads to an immediate uncontrolled descent.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Autorotation Loss of control in flight defining event
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Aircraft › Aircraft propeller/rotor › Rotorcraft flight control › Main rotor control › Incorrect use/operation
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Prop/rotor parameters › Not attained/maintained
- cause Personnel issues › Task performance › Use of equip/info › Use of equip/system › Flight crew
- cause Personnel issues › Action/decision › Action › Incorrect action performance › Flight crew
Flight instructor
- Certificate: flight instructor, commercial pilot
- Ratings: instructor: helicopter; instructor: instrument helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 1,012 hours in all; 1,010 in this make and model
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: rgt
- Injury: fatal
Dual student
- Certificate: commercial pilot
- Ratings: rotorcraft: helicopter
- Flight time: 205 hours in all; 202 in this make and model
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rgt
- Injury: fatal
The aircraft
- Airframe total time: 10,147 hours
- Last inspection: 100-hour inspection, August 21, 2009
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-320-B2C (piston); 0 hours total
- Fire on the ground
- Operator: Hillsboro Aviation INC
The flight
- Departed from: HIO Hillsboro OR at 7:04 pm
- Destination: HIO Hillsboro OR
- Flight plan: none
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 350° at 5 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 68°F (20°C), dew point 46°F (8°C)
- Altimeter: 30.35 inHg
- Observation at 7:53 pm from KHIO
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 2 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.