# NTSB CHI91LA146: Robinson R22 Beta, N2360K, Ann Arbor, MI, May 5, 1991

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: May 5, 1991, 17:38 local (21:38 UTC)
- Place: Ann Arbor, MI
- Coordinates: 42.269599, -83.729217 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=42.2696&lon=-83.7292&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report June 2, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 15056
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI91LA146
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/15056/pdf
- Page: https://openairdocs.org/ntsb/CHI91LA146

## Probable cause

LOSS OF ENGINE POWER DUE TO CARBURETOR ICE, AND THE PILOT'S FAILURE TO USE CARBURETOR HEAT.    FACTORS RELATED TO THE ACCIDENT WERE:  CARBURETOR ICING CONDITIONS, AND A FALSE INDICATION FROM THE CARBURETOR AIR TEMPERATURE GAGE.

## Sequence of events

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

- Loss of engine power(total) - nonmechanical, approach
  - weather condition - carburetor icing conditions (contributing factor)
  - engine instruments,carb air temp gage - false indication (contributing factor)
  - fuel system,carburetor - ice (cause)
  - carburetor heat - not used, pilot in command (cause)
- Forced landing, landing
  - autorotation - performed, pilot in command
- Roll over, landing

## Analysis

THE PLT RPRTD THAT DURING FLT, HE NOTED RPM FLUCTUATIONS & A WARNING BUZZER.  HE ADJUSTED THE THROTTLE TO 100% & NOTED THAT ALL GAGES WERE 'IN THE GREEN.'  HE CHECKED THE CARBURETOR (CARB) HEAT GAGE & NOTED IT WAS ONE NEEDLE WIDTH ABOVE THE YELLOW SECTION & THAT THE OUTSIDE AIR TEMP WAS 9 DEG C (48 DEG F).  WITH THESE INDCNS, HE DISCOUNTED CARB ICE & DID NOT APPLY CARB HEAT.  SUBSEQUENTLY, THE ENG LOST ADDITIONAL POWER BEFORE THE PLT COULD REACH THE RWY.  DURING AN EMERG LANDING, THE HELICOPTER ROLLED OVER.  AN EXAM & SUBSEQUENT ENG RUN REVEALED NO MECHANICAL ANOMALIES, EXCEPT THAT THE CARB AIR TEMP GAGE WAS INDICATING 4 DEG C ABOVE THE ACTUAL TEMP.  TEMP & DEW POINT AT ANN ARBOR WERE 51 & 50 DEG F, RESPECTIVELY.  ACCORDING TO CARB ICE CHARTS, CONDITIONS WERE CONDUCIVE TO CARB ICE.

## Aircraft

- Registration: [N2360K](https://openairdocs.org/deregistered/N2360K-2013-06-13), registration cancelled 2013-06-13, S/N 0525 (OpenAirDocs)
- Reported make and model: ROBINSON R22 BETA
- Registry model: [Robinson Helicopter R22 BETA](https://openairdocs.org/model/robinson-helicopter-r22-beta) (registry code 7640110) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 0525
- Engines: LYCOMING O-320-B2C 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Lutz, Robert A
- Registered owner: Unknown
- Last inspection: 100 hour, April 4, 1971, 30 hours before
- Departed: PRIV, ANN ARBOR, MI
- Flight plan: Unknown
- Airport: Ann Arbor

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 59; commercial, private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; flight hours: 1,355 total, 65 in this make and model, 1,055 as pilot in command, 19 in the last 90 days, 6 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Instrument (IMC), Day
- Wind: 130° at 14 knots
- Visibility: 2 statute miles
- Lowest ceiling: 1,000 ft overcast
- Temperature: 52 °F, dew point 50 °F
- Altimeter: 29.00 inHg
- Observed at: ARB

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19910505016949A](https://openairdocs.org/incident/19910505016949A), May 5, 1991: Robsin R22BETA, Ann Arbor, MI, Substantial damage. Engine quit approaching airport. Allowed rotor RPM decay. Tumbled on impact. Did not use carb heat. Gauge in error

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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