- Date
- July 29, 2009, 11:00 local (18:00 UTC)
- Place
- Troutdale, OR
- Injuries
- 2 minor
- Damage
- Substantial damage
- Phase of flight
- Emergency descent
- Aircraft
- N7176WRobinson Helicopter R22 Beta
- Defining event
- Autorotation: Hard landing
- Weather
- Visual (VMC) · Day
- Status
- Completed · report September 30, 2009
- Report
- Approved by Office Director
- NTSB office
- Western Pacific Region
- Parties
- Federal Aviation Administration
- FAA report
- 20090729013229A
- Case key
- 74398
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 flight instructor's failure to maintain adequate main rotor RPM.
Findings · 2
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
After practicing a series of autorotations, the flight instructor and his student attempted to complete a 180-degree autorotation. The student began a stabilized autorotation from the downwind leg of the traffic pattern. According to the flight instructor, during the turn the student allowed the nose of the helicopter to drop; he was instructed to correct this attitude by applying aft cyclic. When the student completed the turn at an altitude of 200 to 250 ft agl and at a speed of 80 to 85 knots, the flight instructor believed that the outcome of the maneuver was in doubt. The flight instructor then took control of the helicopter and began to initiate a recovery by raising the nose and attempting to increase the throttle and collective to arrest the descent rate. According to the flight instructor, the RPM decayed and the low rotor rpm horn came on at 150 to 100 ft agl. The helicopter landed hard and subsequently slid off the north side of the taxiway. The forward section of the left skid contacted the soft dirt, which resulted in the helicopter turning to the left and nosing over. Examination of the aircraft by a Federal Aviation Administration inspector revealed substantial damage to the helicopter consisted of the separation of the tail boom assembly, damage to the firewall, the left forward frame, and left skid support structure. The flight instructor reported no mechanical anomalies with the helicopter or flight control systems.
Factual narrative
After practicing a series of autorotations, the flight instructor and his student attempted to complete a 180-degree autorotation. The student began a stabilized autorotation from the downwind leg of the traffic pattern. According to the flight instructor, during the turn the student allowed the nose of the helicopter to drop; he was instructed to correct this attitude by applying aft cyclic. When the student completed the turn at an altitude of 200 to 250 ft agl and at a speed of 80 to 85 knots, the flight instructor believed that the outcome of the maneuver was in doubt. The flight instructor then took control of the helicopter and began to initiate a recovery by raising the nose and attempting to increase the throttle and collective to arrest the descent rate. According to the flight instructor, the RPM decayed and the low rotor rpm horn came on at 150 to 100 ft agl. The helicopter landed hard and subsequently slid off the north side of the taxiway. The forward section of the left skid contacted the soft dirt, which resulted in the helicopter turning to the left and nosing over. Examination of the aircraft by a Federal Aviation Administration inspector revealed substantial damage to the helicopter consisted of the separation of the tail boom assembly, damage to the firewall, the left forward frame, and left skid support structure. The flight instructor reported no mechanical anomalies with the helicopter or flight control systems.
Aircraft
- Registration
- N7176W
- Reported as
- Robinson Helicopter R22 Beta
- Category
- Helicopter
- Serial number
- 2735
- Airframe hours
- 6,135
- Engine
- Lycoming O-360-A1D, 180 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Instructional · Part 91
- Operator
- Hillsboro Aviation Inc
- Registered owner
- Hillsboro Aviation Inc
- Airworthiness certificate
- Standard, Normal
- Last inspection
- 100 hour · July 2, 2009 · 99 hours before
- Departed
- KTTD · Troutdale, OR
- Destination
- KTTD · Troutdale, OR
- Airport
- KTTD · Portland-Troutdale, runway 25, 5,399 × 150 ft, asphalt
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 · 2
As NTSB recorded them. NTSB leaves out names.
- Role
- Flight instructor
- Age
- 24
- Injuries
- Minor
- Certificates
- Commercial, Flight instructor
- Instrument ratings
- Helicopter
- Medical
- Class 1, Without waivers/limitations
- Last flight review
- March 16, 2009
- Seat
- Left
- Flight hours
- 1,130 total · 1,116 in this make and model · 1,040 as pilot in command · 192 in the last 90 days · 99 in the last 30 days · 0 in the last 24 hours
- Role
- Student pilot
- Age
- 26
- Injuries
- Minor
- Certificate
- Student
- Medical
- Class 3, Without waivers/limitations
- Seat
- Right
- Flight hours
- 57 total · 57 in this make and model · 5 as pilot in command · 57 in the last 90 days · 42 in the last 30 days · 0 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 100° at 14 knots, gusting 22
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 93 °F, dew point 61 °F
- Altimeter
- 29.76 inHg
- Observed at
- KTTD
Docket · 1
The files NTSB released with the investigation on August 14, 2009, on NTSB’s docket system: statements, records, photos and specialists’ reports. 617 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.