# NTSB ATL89LA037: Cessna R172E, N96164, Lawrenceville, GA, November 15, 1988

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: November 14, 1988, 20:45 local (Nov 15, 1988, 01:45 UTC)
- Place: Lawrenceville, GA
- Location: 33.9529° N, 83.9922° W: Placed by OpenAirDocs: center of Lawrenceville, GA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=33.9529&lon=-83.9922&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor, 1 uninjured
- Status: Completed, report January 16, 1990
- Report: Approved by Office Director
- NTSB case key (mKey): 7955
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL89LA037
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/7955/pdf
- Page: https://openairdocs.org/ntsb/ATL89LA037

## Probable cause

IMPROPER REPAIR AND/OR MODIFICATION OF THE CARBURETOR AIRBOX BY UNKNOWN PERSON(S), AND THE SUBSEQUENT FAILURE OF MAINTENANCE PERSONNEL TO DETECT THE IMPROPER REPAIR/MODIFICATION DURING ANNUAL INSPECTION(S), WHICH LED TO A LOSS OF POWER DUE TO CARBURETOR ICING. A CONTRIBUTING FACTOR WAS THE PRESENCE OF WEATHER CONDITIONS CONDUCIVE TO THE FORMATION OF CARBURETOR ICE.

## Sequence of events

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

- Loss of engine power(partial) - nonmechanical, takeoff - initial climb
  - maintenance - improper, other maintenance personnel (cause)
  - carburetor heat control - binding(mechanical) (cause)
  - carburetor heat control - movement restricted (cause)
  - weather condition - carburetor icing conditions (contributing factor)
  - fuel system,carburetor - ice (cause)
- Forced landing, descent - emergency
- In flight collision with object, landing
  - light condition - night (contributing factor)
  - object - tree(s) (contributing factor)

## Analysis

THE CFI & STUDENT WERE PRACTICING TOUCH-&-GO LNDGS AT NIGHT WHEN THE ENG LOST PWR SHORTLY AFTER THE 5TH TOUCH-&-GO. SUBSEQUENTLY, THE ACFT WAS DMGD WHEN IT WAS LNDD IN TREES. DRG AN EXAM OF THE ENG, DARK, SOOTY DEPOSITS WERE FOUND ON ALL SPARK PLUGS. THE PLUGS WERE REINSTALLED & AN OPNL CHECK OF THE ENG WAS MADE. THE ENG STARTED ALMOST IMMEDIATELY & DEVELOPED PWR WHEN THE THROTTLE WAS OPENED. A FURTHER EXAM REVEALED THAT THE CARB HEAT DOOR ON THE CARB AIRBOX WOULD NOT MOVE TO THE FULL ON POSITION WHEN THE CARB HEAT CONTROL WAS ACTIVATED. THE AIRBOX HAD BEEN IMPROPERLY MODIFIED AND/OR REPAIRED. NO ENTRIES WERE FOUND IN THE ACFT LOGS CONCERNING THE AIRBOX. THE ACFT HAD FLOWN APRX 97 HRS SINCE THE PREVIOUS ANNUAL INSPN APRX 5 MOS BEFORE THE ACDNT. THE TEMP & DEW POINT WERE 61 & 45 DEG, RESPECTIVELY. ACCORDING TO ICING PROBABILITY CHARTS, CONDS WERE CONDUCIVE TO CARB ICE. THE CFI RPRTD THE CARB HEAT WAS USED PRIOR TO EACH LNDG.

## Aircraft

- Registration: [N96164](https://openairdocs.org/deregistered/N96164-1992-02-05), registration cancelled 1992-02-05, S/N R1720081 (OpenAirDocs)
- Reported make and model: CESSNA R172E
- Registry model: [Cessna R172E](https://openairdocs.org/model/cessna-r172e) (registry code 2072413) (OpenAirDocs)
- Category: Airplane
- Serial number: R172-0081
- Airframe hours: 8249
- Engines: LYCOMING O-360-A1A 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Registered owner: Civil Air Patrol, Inc.
- Airworthiness certificate: Standard, Normal; Standard, Utility
- Last inspection: Annual, June 14, 1988, 97 hours before
- Departed: PDK, ATLANTA, GA
- Airport: 17A, Gwinnett County, runway 25, 4,000 × 75 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 42; flight instructor, private, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: right; flight hours: 2,160 total, 38 in this make and model, 1,359 as pilot in command, 16 in the last 90 days, 6 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Night/bright
- Wind: calm
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 61 °F, dew point 45 °F
- Altimeter: 30.00 inHg
- Observed at: AHN, 32 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 19881114050729A](https://openairdocs.org/incident/19881114050729A), Nov 14, 1988: Cessna R172E, Lawrenceville, GA, Substantial damage. Engine lost power on climbout. Crashed into trees. Carb heat door was not closing. Had been improperly riveted.

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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.