# NTSB LAX00LA237: Cessna 150M, N704QJ, El Monte, CA, June 21, 2000 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 21, 2000, 11:30 local (18:30 UTC) - Place: El Monte, CA - Coordinates: 34.080177, -118.02922 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.0802&lon=-118.0292&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report August 21, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 49489 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX00LA237 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/49489/pdf - Page: https://openairdocs.org/ntsb/LAX00LA237 ## Probable cause The inadequate maintenance inspection by other maintenance personnel of the exhaust system that resulted in an eroded muffler that allowed hot gases to impinge on magneto wiring and resulted in loss of engine power. A factor was the soft terrain at the forced landing site. ## 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 - exhaust system,muffler - eroded (cause) - ignition system,ignition lead - burned (cause) - ignition system,magneto grounding lead (p-lead) - melted (cause) - ignition system,magneto grounding lead (p-lead) - shorted (cause) - maintenance,inspection - inadequate, other maintenance personnel (cause) - ignition system,ignition lead - burned (cause) - Forced landing, descent - emergency - Nose over, emergency landing - terrain condition - soft (contributing factor) - terrain condition - open field ## Analysis During cruise, the engine lost power then nosed over during a forced landing in an open, dirt field. No mechanical anomalies were experienced with the engine sound or gages prior to the loss of engine power. About 10 minutes into the flight the engine began to run roughly. The CFI performed the emergency checklist and picked one of two open fields to make a forced landing. During the approach to the second field, a construction vehicle drove into their flight path. The CFI shortened the approach and landed in the first field. On the landing roll the nose wheel dug into the dirt and the airplane nosed over. The external examination of the engine revealed that the left muffler end cap had separated in an outward direction from the muffler about 350 degrees in circumference in a 45-degree angle. This allowed heat to be directed at the firewall. The P-leads located within the electrical harness were melted, which allowed the conductors to short within the wires. ## Factual narrative On June 21, 2000, about 1130 hours Pacific daylight time, a Cessna 150M, N704QJ, lost engine power and nosed over during a forced landing in an open field near the El Monte, California, airport. The airplane, operated by Valley Flight Center under 14 CFR Part 91 as an instructional flight, sustained substantial damage. The certified flight instructor and the student pilot were not injured. Visual meteorological conditions existed for the local area flight, and no flight plan had been filed. The airplane departed from the El Monte airport at 1045. In an interview with a Safety Board investigator, the instructor reported no discrepancies with the airplane during the preflight, or the one takeoff and landing that was conducted prior to departing for the practice area. In the 10 minutes it took to arrive at the practice area he noted nothing unusual about the engine sounds or power output. The engine then began to run roughly just after the instructor requested a frequency change from the El Monte Air Traffic Control Tower (ATCT). He took the controls and performed the emergency checklist items. The engine was still losing power and the instructor contacted ATCT personnel and informed them of his situation and his intention to make a forced landing. The instructor reported two fields were available for the landing. The first field was undeveloped, and the far field was level with a dirt road. Prior to reaching the far field he noted a construction vehicle on his intended landing area. He shortened the landing approach, and made a soft field landing in the first field. The instructor stated that when the nose wheel contacted the ground, it dug into the dirt, and the airplane nosed over. AIRCRAFT INFORMATION The Safety Board investigator reviewed the airplane and power plant logbooks. The last 100-hour inspection was conducted on May 8, 2000. The last annual inspection was completed on September 27, 1999. TEST AND RESEARCH The airplane was inspected at Ben's Aircraft Maintenance on June 22, 2000, in El Monte. A visual inspection of the engine revealed that the left muffler end cap had separated from the muffler approximately 350 degrees in circumference. The end cap was pushed outward about 45 degrees. Heat from the open muffler end cap could be directed at the firewall. The electrical wire harness had melted and the paint on the firewall had "bubbled." The muffler end cap was removed. The baffles inside the muffler were eroded. The top spark plugs were removed. According to the Champion Aviation Check-A-Plug AV-27 chart, the spark plugs displayed coloration consistent with normal operation. Crankshaft rotation produced little or no thumb compression. Investigators attributed the weak compression to dirt in the cylinders. Compressed air was placed in the spark plug holes and the dirt was blown out. Another compression check was conducted with compression obtained in all cylinders in firing order. During the rotation of the crankshaft the magnetos did not produce spark. Use of a multimeter verified that the electrical harness was melted and the P-leads were grounded, which allowed an internal short within the wires. The P-leads were disconnected. The magnetos were manually rotated and produced spark. No further discrepancies were noted. ## Aircraft - Registration: [N704QJ](https://openairdocs.org/deregistered/N704QJ-2021-02-27), registration cancelled 2021-02-27, S/N 15078787, built 1976 (OpenAirDocs) - Reported make and model: Cessna 150M - Registry model: [Cessna 150M](https://openairdocs.org/model/cessna-150m) (registry code 2071830) (OpenAirDocs) - Registry engine: [Continental 0-200 series](https://openairdocs.org/engine/continental-0-200-series) (registry code 17020, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 15078787 - Airframe hours: 11044 - Engines: Continental O-200-A 100 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Valley Flight Center - Airworthiness certificate: Standard, Utility - Last inspection: 100 hour, May 8, 2000, 78 hours before - Departed: EMT ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 24; commercial, flight instructor; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 1,216 total, 120 in this make and model, 1,142 as pilot in command, 190 in the last 90 days, 70 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 7 knots - Visibility: 3 statute miles - Lowest ceiling: none - Altimeter: 29.00 inHg - Observed at: EMT ## 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 20000621011159A](https://openairdocs.org/incident/20000621011159A), Jun 21, 2000: Cessna 150M, El Monte, CA, Substantial damage. (-23) VFR instructional flight was making approach to EMT when pilot declared emergency. Pilot informed tower that they would not make the airport. A/c landed… ## Other investigations on N704QJ (2) 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 WPR20LA022](https://openairdocs.org/ntsb/WPR20LA022), Nov 13, 2019: Cessna 150 (N704QJ), Red Rock, AZ, substantial damage. Probable cause: A total loss of engine power due to carburetor icing. Contributing to the accident was the pilot’s improper use of carburetor heat. - [NTSB LAX96LA011](https://openairdocs.org/ntsb/LAX96LA011), Oct 16, 1995: Cessna 150M (N704QJ), Brea, CA, substantial damage. Probable cause: fuel exhaustion due to the pilot's improper leaning procedures and his failure to use the performance charts in the pilot operating handbook to determine fuel consumption rates for the selected… 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.