# NTSB LAX92LA089: Cessna 172N, N1571E, Show Low, AZ, January 12, 1992

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: January 12, 1992, 08:40 local (15:40 UTC)
- Place: Show Low, AZ
- Coordinates: 34.230144, -110.070579 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=34.2301&lon=-110.0706&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report August 13, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27536
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX92LA089
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27536/pdf
- Page: https://openairdocs.org/ntsb/LAX92LA089

## Probable cause

THE FAILURE OF THE CARBURETOR HEAT BOX ATTACH STRAPS WHICH ALLOWED THE CARBURETOR HEAT BOX TO SEPARATE FROM THE EXHAUST SYSTEM HEAT MUFF AND RENDERED THE CARBURETOR HEAT SYSTEM INOPERATIVE.  THE ENGINE THEN LOST POWER DUE TO CARBURETOR ICE.

## Sequence of events

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

- Loss of engine power(total) - mech failure/malf, cruise - normal
  - carburetor heat control,torque box - separation (cause)
  - carburetor heat - not possible, pilot in command (cause)
  - weather condition - carburetor icing conditions (cause)
  - weather condition - clouds
- Forced landing, descent - emergency
  - terrain condition - none suitable
  - weather condition - clouds
  - visual lookout - restricted, pilot in command
- On ground/water encounter with terrain/water, landing - roll
  - terrain condition - rough/uneven
  - terrain condition - ditch

## Analysis

THE PILOT SAID WHILE IN LEVEL CRUISE ON AN IFR FLIGHT THE ENGINE BEGAN TO LOOSE POWER DUE TO CARBURETOR ICE AND ATTEMPTS TO REMEDY THE SITUATION WERE UNSUCCESSFUL WITH THE ENGINE EVENTUALLY LOOSING ALL POWER. THE PILOT DECLARED AN EMERGENCY WITH ALBUQUERQUE CENTER AND WAS RADAR VECTORED TOWARD THE SHOW LOW AIRPORT. THE FLIGHT WAS INTERMITTENTLY IN CLOUDS DURING THE EMERGENCY DESCENT AND BROKE OUT AT A LOW ALTITUDE. THE AIRCRAFT HAD INSUFFICIENT ALTITUDE TO MAKE THE AIRPORT AND LANDED IN THE ONLY AVAILABLE LOCATION, A FIELD ABOUT 23 MILES FROM THE AIRPORT. DURING ROLL OUT, THE AIRCRAFT COLLIDED WITH A DITCH AND NOSED OVER. POST ACCIDENT EXAMINATION OF THE AIRCRAFT BY FAA INSPECTORS REVEALED THAT THE CARBURETOR HEAT BOX HAD SEPARATED FROM THE HEAT MUFF OF THE EXHAUST SYSTEM AND WAS HANGING LOOSE IN THE COWLING ATTACHED ONLY BY THE FABRIC HOSE. A METAL BAND WHICH ATTACHES THE CARB HEAT BOX TO THE MUFF HAD SEPARATED. CHAFFING ON THE COWLING IN THE AREA OF WHERE THE HEAT BOX WAS HANGING INDICATED IT HAD BEEN SEPARATED FOR SOME TIME. THE LAST 100 HOUR INSPECTION WAS ACCOMPLISHED 80 OPERATING HOURS PRIOR TO THE ACCIDENT.

## Aircraft

- Registration: [N1571E](https://openairdocs.org/aircraft/N1571E), registered now, S/N 17271049, built 1978 (OpenAirDocs)
- Reported make and model: CESSNA 172N
- Registry model: [Cessna 172N](https://openairdocs.org/model/cessna-172n) (registry code 2072434) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 17271049
- Airframe hours: 9000
- Engines: LYCOMING O-320-H2AD 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: K & M Aviation
- Registered owner: K & M Aviation
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, November 30, 1991, 80 hours before
- Departed: DVT, PHOENIX, AZ
- Destination: ABQ, ALBUQUERQUE, NM
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 21; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 171 total, 56 in this make and model, 122 as pilot in command, 38 in the last 90 days, 32 in the last 30 days, 7 in the last 24 hours

## Weather

- Conditions: Instrument (IMC), Day
- Wind: 190° at 10 knots
- Visibility: 5 statute miles
- Lowest ceiling: 800 ft broken
- Temperature: 25 °F, dew point 21 °F
- Altimeter: 29.00 inHg
- Observed at: SOW, 25 nm away

## 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 19920112000399A](https://openairdocs.org/incident/19920112000399A), Jan 12, 1992: Cessna 172N, Show Low, AZ, Substantial damage. Engine quit en route IFR. Nosed over on forced landing. Carb heat box had separated from exhaust system.

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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