# NTSB SEA07CA171: Robinson R22 Beta II, N712U, Park City, UT, June 18, 2007

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Data collection · Final report
- Date: June 18, 2007, 13:20 local (19:20 UTC)
- Place: Park City, UT
- Coordinates: 40.688888, -111.480552
- Nearby events: https://openairdocs.org/map.md?lat=40.6889&lon=-111.4806&mi=10
- Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report October 31, 2007
- Report: Approved by Office Director
- NTSB case key (mKey): 66328
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA07CA171
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/66328/pdf
- Page: https://openairdocs.org/ntsb/SEA07CA171

## Probable cause

The pilot's failure to maintain rotor RPM during hover taxi.  A contributing factor was the high density altitude weather condition.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Hard landing, taxi - aerial
  - rotor rpm - low, pilot in command (cause)
  - weather condition - high density altitude (contributing factor)

## Analysis

The flight instructor said that he was on a cross-country training flight with a student.  He said he was going to demonstrate an emergency autorotation to an open plateau with an elevation of approximately 7,000 feet.  The flight instructor said the autorotation went well.  But when he completed a right pedal turn to taxi back and applied left pedal to stop the yaw, the low rotor RPM horn sounded.  He lowered the collective and rolled on the throttle as the helicopter settled to the ground. The left skid impacted first, bending the left aft skid support tube, which transmitted to the fuselage structure bending and deforming it.

## Factual narrative

The flight instructor said that he was on a cross-country training flight with a student.  He said he was going to demonstrate an emergency autorotation to an open plateau with an elevation of approximately 7,000 feet.  The flight instructor said the autorotation went well.  But when he completed a right pedal turn to taxi back and applied left pedal to stop the yaw, the low rotor RPM horn sounded.  He lowered the collective and rolled on the throttle as the helicopter settled to the ground. The left skid impacted first, bending the left aft skid support tube, which transmitted to the fuselage structure bending and deforming it.

## Aircraft

- Registration: [N712U](https://openairdocs.org/aircraft/N712U), registered now, S/N 3676, built 2004 (OpenAirDocs)
- Reported make and model: Robinson R22 Beta II
- Registry model: [Robinson Helicopter R22](https://openairdocs.org/model/robinson-helicopter-r22) (registry code 7640102) (OpenAirDocs)
- Registry engine: [Lycoming O-360 series](https://openairdocs.org/engine/lycoming-o-360-series) (registry code 41575, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 3676
- Engines: Lycoming O-360-J2A 145 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Upper Limit Aviation
- Registered owner: Tumbleweed Leasing Co. Inc.
- Airworthiness certificate: Standard, Normal
- Departed: SLC, Salt Lake City, UT
- Destination: PRIV, Park City, UT

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Flight instructor; age 21; injuries: none; commercial, flight instructor; instrument ratings: helicopter; medical: class 2, without waivers/limitations; seat: left; flight hours: 500 total, 500 in this make and model, 1 in the last 24 hours
- Student pilot; age 35; injuries: none; private; medical: class 2, with waivers/limitations; seat: right

## Weather

- Conditions: Visual (VMC), Day
- Wind: 260° at 5 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 72 °F, dew point 27 °F
- Altimeter: 30.11 inHg
- Observed at: PVU

## Other investigations on N712U (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB WPR13LA315](https://openairdocs.org/ntsb/WPR13LA315), Jul 8, 2013: Robinson Helicopter R22 (N712U), Alta, UT, destroyed. Probable cause: The flight instructor's decision to follow a route over mountainous terrain in conditions that exceeded the helicopter’s ability to maintain terrain clearance.

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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