# NTSB LAX04LA251: Socata TB-20, N110U, Perris, CA, June 28, 2004 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 28, 2004, 14:39 local (21:39 UTC) - Place: Perris, CA - Coordinates: 33.799999, -117.416664 - Nearby events: https://openairdocs.org/map.md?lat=33.8000&lon=-117.4167&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 5 uninjured - Status: Completed, report July 7, 2005 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 59523 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX04LA251 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/59523/pdf - Page: https://openairdocs.org/ntsb/LAX04LA251 ## Probable cause A loss of engine power due to oil exhaustion as a result of the mechanic's use of an incorrect gasket during the installation of the vacuum pump. ## 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 - fluid,oil - exhaustion (cause) - maintenance,installation - inadequate, pilot in command (cause) - lubricating system,oil gasket - incorrect (cause) - engine assembly - seized - Forced landing, descent - emergency - On ground/water encounter with terrain/water, emergency landing - terrain condition - berm ## Analysis The airplane collided with ground obstructions during a forced landing following a catastrophic engine failure due to oil exhaustion during cruise flight. Just after achieving cruise altitude the pilot was scanning the cockpit gauges and he noticed the oil pressure gauge indicating a loss of pressure, with the oil warning light flickering intermittently. About 5 minutes later, the engine started to vibrate, and subsequently seized, making a loud bang. The airplane began to descend about 1,000 feet per minute, and the pilot selected a dirt field to perform an emergency landing. During the landing roll, the airplane impacted a berm. An engine examination revealed that the inside top of the engine cowling showed a concentration of oil near the firewall on the left side, which is the approximate location of the vacuum pump. Removal of the vacuum pump revealed an oily film on both sides of the pump gasket, which is seated between the vacuum pump flange and the engine accessory case flange. The vacuum pump had been installed about 0.5 hours prior to the accident. The mechanic who installed the pump said he used the gasket that was supplied with the pump. The manufacturer of the vacuum pump reported that they supply a gasket (part number AS3491-01) with their pump. In the TB-20 parts manual, the airplane manufacturer specifies that the gasket required is part number Z00.N7423254013, which they cross-reference with Textron Lycoming part number 8313. The investigation was unable to cross-reference or establish an equivalency between the AS3491-01 gasket supplied by the pump manufacturer with either the Lycoming or Socata specified gasket. ## Factual narrative HISTORY OF FLIGHT On June 28, 2004, at 1439 Pacific daylight time, a Socata TB-20, N110U, collided with a berm during a forced landing following a total loss of engine power during cruise flight near Perris, California. The pilot/owner was operating the airplane under the provisions of 14 CFR Part 91. The private pilot and four passengers were not injured. The airplane sustained substantial damage. The personal cross-country flight departed French Valley Airport, Murrieta, California, about 1400, with a planned destination of Reno, Nevada. Visual meteorological conditions prevailed, and a flight plan had not been filed. The wreckage was at 33 degrees 48 minutes north latitude and 117 degrees 25 minutes west longitude. During a telephone interview with a National Transportation Safety Board investigator, the pilot stated that after the initial climb, he leveled the airplane out at 10,500 feet mean sea level (msl). While configuring the airplane for cruise flight, he scanned the cockpit gauges and noticed that the oil pressure needle was in the yellow-green arc transition area, indicating a loss of pressure. He also noted that the oil warning light was flickering intermittently. He opted to return back to French Valley and contacted Ontario Approach advising them of his new itinerary. About 5 minutes after the call, the engine started to vibrate, and subsequently seized, making a loud bang. Smoke emitted from the engine and entered the cockpit area. The pilot further reported that the airplane began to descend about 1,000 feet per minute, and he selected a dirt field to perform an emergency landing. During the landing roll, the airplane impacted a berm; the nose gear collapsed, and the airplane came to rest on its nose. After egressing the airplane, the pilot measured the landing ground scar to be about 1,100 feet. The airplane incurred damage to the nose gear and the left wing. PERSONNEL INFORMATION The pilot reported that during the 90-day period preceding the accident, he had flown about 16 hours, all of which were in the accident airplane. His cumulative flying experience totaled 1,018 hours, of which 919 where in the same make and model airplane. The pilot's last flight review was satisfactorily accomplished in the accident airplane on September, 21, 2003. AIRCRAFT INFORMATION The engine was a Lycoming IO-540-C4D5D, serial number L-22959-48A. In the Lycoming Operator's Manual, the indicated oil sump capacity for the engine is 12 quarts, with the minimum safe quantity in the sump 4 quarts. It also stated that the normal operating oil pressure should be at maximum 90 pounds per square inch (psi) and at minimum 60 psi. TESTS AND RESEARCH Oil Leak Documentation. Safety Board investigators and an investigator from Textron Lycoming, who was a party to the investigation, conducted an engine examination at Aircraft Recovery Services, Littlerock, California. The tachometer revealed a total time of 1,782.15. Investigators attempted to drain residual oil from the engine's oil sump, but recovered no oil. They examined the engine and its accessories in an effort locate the source of the oil leak. The engine's crankcase was cracked in numerous locations, with a hole about 3/4 inch in diameter located at the top of the crankcase, near the number 2 cylinder. Oil residue was sporadically dispersed on the exterior of the engine and on the accessory case. Investigators found no evidence of broken or disconnected hoses. The top of the engine cowling showed a concentration of oil near the firewall on the left side, which is the approximate location of the vacuum pump. Removal of the vacuum pump, revealed an oily film on its gasket, part number AS3491-01 (seated between the vacuum pump flange and the engine accessory case flange). The film coated the lower portion of both sides of the gasket (see photographs showing the gasket). Also noted were small pieces of foreign debris on both the surface of the gasket and vacuum pump flange. Logbooks and Maintenance History. A review of the airplane's logbooks revealed that the vacuum pump had been installed at a tachometer time of 1,781.6, about 0.5 hours prior to the accident. A Safety Board investigator interviewed, by telephone, an airplane mechanic at French Valley Aviation, Murrieta, the Federal Aviation Administration certified maintenance facility that performed the installation of the vacuum pump. The mechanic reported that he installed the pump with the gasket that was supplied with the pump. The manufacturer of the vacuum pump, Rapco, Inc., supplies a gasket (part number AS3491-01) with their pump. In the TB-20 parts manual, the airplane manufacturer specifies that the gasket required is part number Z00.N7423254013, which they cross-reference with Textron Lycoming part number 8313. Despite numerous attempts, a Safety Board investigator was unable to cross-reference the gasket AS3491-01 with gasket 8313. ADDITIONAL INFORMATION The Safety Board investigator released the airplane wreckage to Aircraft Recovery Services on July 8, 2004. ## Aircraft - Registration: [N110U](https://openairdocs.org/aircraft/N110U), registered now, S/N 595 (OpenAirDocs) - Reported make and model: SOCATA TB-20 - Registry model: [Socata TB-20 TRINIDAD](https://openairdocs.org/model/socata-tb-20-trinidad) (registry code 8680695) (OpenAirDocs) - Registry engine: [Lycoming IO-540 series](https://openairdocs.org/engine/lycoming-io-540-series) (registry code 41530, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 595 - Airframe hours: 1750 - Engines: Lycoming IO-540-C4D5D 250 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Schaeffer Industries - Airworthiness certificate: Standard, Normal - Last inspection: Annual, November 29, 2003, 32 hours before - Departed: F70, Murrieta, CA - Destination: RNO, Reno, NV ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; injuries: none; private; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; last flight review September 21, 2003; seat: left; flight hours: 1,018 total, 919 in this make and model, 934 as pilot in command, 16 in the last 90 days, 2 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 290° at 12 knots - Visibility: 9 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 57 °F - Altimeter: 29.90 inHg - Observed at: RAL ## 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 20040628011109A](https://openairdocs.org/incident/20040628011109A), Jun 28, 2004: Socata TB20TRINIDAD, Riverside, CA, Substantial damage. (-23) Aircraft was on climb at approximately 10,500 ft when it encountered a low oil pressure indication. Pilot contacted March tower and advised them that he… 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.