# NTSB LAX00LA019: Cessna TR182, N756LE, Fresno, CA, October 19, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 19, 1999, 09:30 local (16:30 UTC) - Place: Fresno, CA - Coordinates: 36.800472, -119.800628 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.8005&lon=-119.8006&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report May 17, 2001 - Report: Approved by Office Director - ADs cited in the narratives: [AD 96-12-07](https://openairdocs.org/ad/96-12-07) (OpenAirDocs) - NTSB case key (mKey): 47657 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX00LA019 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/47657/pdf - Page: https://openairdocs.org/ntsb/LAX00LA019 ## Probable cause Inadequate maintenance inspection mandated by the FAA, and the inadequate design of the exhaust heater core/muffler and deflectors that failed to divert hot exhaust gasses away from the battery and cabin heat valve. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, climb - to cruise - exhaust system,muffler - failure,total (cause) - maintenance,inspection - inadequate, other maintenance personnel - procedure inadequate, faa(other/organization) (cause) - Fire, cruise - exhaust system,end plate - eroded (cause) - acft/equip,inadequate design, manufacturer (cause) - Forced landing, descent - emergency - terrain condition - none suitable - weather condition - haze/smoke - On ground/water collision with object, landing - roll - object - vehicle ## Analysis The pilot departed on a VFR cross-country flight. While cruising at 9,500 feet msl, smoke filled the cockpit, coming from the engine compartment. The pilot was monitoring the local approach control. He declared an emergency and started a descent. He was unable, however, to see an airport in the immediate area due to limited forward visibility. He subsequently landed in a residential area under development and collided with two parked cars. Postaccident examination of the engine compartment revealed that the exhaust heater core aft end plate had failed and was open. The end plate was found in the engine compartment. The failure caused the right side exhaust to exit directly at the firewall, partially separated by the airplane battery and cabin air-mixing valve. ## Factual narrative HISTORY OF FLIGHT On October 19, 1999, about 0930 hours Pacific daylight time, a Cessna TR182, N756LE, made a forced landing 3 miles north of Fresno, California. The pilot declared an emergency due to smoke in the cockpit southeast of the Friant VOR while at 9,500 feet mean sea level. He shutdown the engine and landed on a road and collided with two parked cars. The pilot was not injured. The airplane was substantially damaged, and the cars received minor damage. The personal flight was being operated by the owner/pilot under the provisions of 14 CFR Part 91. Visual meteorological conditions prevailed and no flight plan was filed. The flight originated at Cameron Park, California, at 0820, and was destined for Santa Ana, California. Postaccident examination of the exhaust system by a Federal Aviation Administration (FAA) inspector revealed a failure of the right heater core exhaust collector aft end plate. The end plate was found inside the cowling. Neither Cessna Service Bulletins nor FAA Airworthiness Directives addressed this potential failure. According to the Cessna model R182 and TR182 Service Manual: Exhaust System, section 11A-73, Inspection: "Since exhaust systems of this type are subject to burning, cracking and general deterioration from alternate temperature extremes and vibrations, inspection is important and should be accomplished every 50 hours of operation." According to the FAA inspector's telephone conversation with the maintenance technician, the inspection had been performed using the Cessna maintenance manual. A search of the FAA Service Difficulty Reporting System revealed three similar failures of the heater core assembly at 2,290, 2,223, and 1,762 total flight hours. According to records, the accident airplane heater core failure occurred about 1,313 hours since new. The last annual inspection occurred October 10, 1998, about 64 hours prior to the accident. About 52 hours prior to the accident, a presale inspection of the airplane and engine was accomplished at 1,261.8 hours. During the inspection a new ignition harness and new top spark plugs were installed. The carburetor was overhauled and a new spring was installed on the turbo waste gate. Airworthiness Directive 96-12-07 (Bendix, Impulse Coupling Inspection) was accomplished. The examination of the airplane and failed muffler revealed the absence of internal baffling to dissipate heat and reduce end plate erosion. Additionally, there was no deflector to preclude the impingement of hot gases onto the firewall or attached components such as the battery and the cabin heat valve. The muffler, Cessna part number 2254015-1, and end plate were sent to a materials laboratory for a metallurgical analysis of the failed material. According to design specifications provided by Cessna Aircraft Company, the material is 321 stainless steel per MIL-C-6721, and was 0.031-inch thick sheet. The accident end plate measured 0.015-inch thickness due to internal erosion. The laboratory report is attached. ## Aircraft - Registration: [N756LE](https://openairdocs.org/deregistered/N756LE-2018-01-26), registration cancelled 2018-01-26, S/N R18201101, built 1979 (OpenAirDocs) - Reported make and model: Cessna TR182 - Registry model: [Cessna TR182](https://openairdocs.org/model/cessna-tr182) (registry code 2072735) (OpenAirDocs) - Registry engine: [Lycoming 0-540 series](https://openairdocs.org/engine/lycoming-0-540-series) (registry code 41532, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 01101 - Airframe hours: 1313 - Engines: Lycoming O-540-L3C5D 235 horsepower reciprocating - Damage: Substantial damage - Fire: In-Flight - Flight: Personal, Part 91 - Registered owner: John J. Wilson - Airworthiness certificate: Standard, Normal - Last inspection: Annual, October 10, 1998, 64 hours before - Departed: 061, CAMERON PARK, CA - Destination: SNA, SANTA ANA, CA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 2,000 total, 100 in this make and model, 2,000 as pilot in command, 150 in the last 90 days, 50 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 7 knots - Visibility: 4 statute miles - Lowest ceiling: none - Temperature: 66 °F, dew point 41 °F - Altimeter: 30.00 inHg - Observed at: FAT, 3 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 19991019029729A](https://openairdocs.org/incident/19991019029729A), Oct 19, 1999: Cessna TR182, Fresno, CA, Substantial damage. (.19) On October 19, 1999, about 0930 hours pacific daylight time, a Cessna TR182, N756LE, operated by the owner/pilot, was substantially damaged during a… 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.