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WPR09FA459 · Robinson Helicopter R22 BETA

20 Sept 2009 · Forest Grove, OR, United States

Hillsboro Aviation Robinson Helicopter R22 BETA · Accident: loss of control in flight during autorotation

From Portland Hillsboro Airport (HIO) to Portland Hillsboro Airport (HIO)

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Event

NTSB case
WPR09FA459
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Accident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
API-reported fatalities
2 · all aircraft and ground
Ground fatalities
Unknown
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
General aviation
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Visual Meteorological Cond

Robinson Helicopter R22 BETA

Aircraft type
Robinson R22
Category
Helicopter
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N956SH
Onboard fatalities
Unknown
Route
From Portland Hillsboro Airport (HIO), Hillsboro, ORTo Portland Hillsboro Airport (HIO), Hillsboro, OR
Aircraft age
Not recorded
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 91: General Aviation
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
Autorotation
Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
Loss of control in flight
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Substantial

Cause areas

  • Aircraft › Aircraft oper/perf/capability
  • Aircraft › Aircraft propeller/rotor
  • Personnel issues › Action/decision
  • Personnel issues › Task performance

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

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.

Probable cause

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.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record WPR09FA459
Event ID
20090920X34134
Case number
WPR09FA459
Dataset
full-current
Source SHA-256
5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
  • The date is the local date, which is the same as the UTC date the NTSB stores.
  • API snapshot SHA-256: 25e243b4a191a1f77aa63f15c7b0d7e8247f23023e5788d3a1ccfd2e350759c8; retrieved 2026-09-13T20:28:52.257Z.