# NTSB SEA03LA146: Cessna 182S, N146NE, Henry's Lake, ID, July 21, 2003 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 21, 2003, 12:45 local (18:45 UTC) - Place: Henry's Lake, ID - Coordinates: 44.648612, -111.358055 - Nearby events: https://openairdocs.org/map.md?lat=44.6486&lon=-111.3581&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 5 uninjured - Status: Completed, report June 2, 2004 - Report: Approved by Office Director - Parties: FAA-FSDO - NTSB case key (mKey): 57537 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA03LA146 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/57537/pdf - Page: https://openairdocs.org/ntsb/SEA03LA146 ## Probable cause A set of inadequately torqued vacuum pump retaining nuts, leading to the failure of the vacuum pump gasket, resulting in oil exhaustion, which resulted in a loss of engine power during cruise. A ditch and rough uneven terrain were factors. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - mech failure/malf, cruise - lubricating system,oil gasket - failure (cause) - maintenance,installation - inadequate, other maintenance personnel (cause) - fluid,oil - exhaustion (cause) - miscellaneous,bolt/nut/fastener/clamp/spring - undertorqued (contributing factor) - Forced landing, emergency descent/landing - On ground/water encounter with terrain/water, landing - roll - terrain condition - ditch (contributing factor) - terrain condition - rough/uneven (contributing factor) ## Analysis The pilot reported that about five minutes after takeoff, the oil low pressure light illuminated and shortly thereafter he heard a knocking sound coming from the engine. The pilot shut the engine down and attempted to return to the airport of departure. Unable to make it to the airport, a power-off landing was made to a rough open field about one mile from the runway. Although the touchdown was uneventful, during the landing roll, the aircraft encountered a ditch, which resulted in the separation of the nose gear and substantial damage to the aircraft structure. On site inspection of the aircraft indicated that oil residue was noted at the aft end of the engine around the accessory section. After the tail was lowered, a noticeable oil leak was noted around the vacuum pump flange (approximately 6 drops per minute). Further inspection of the engine found that the pneumatic pump gasket had failed and was blown out the top between the mating surfaces of the pump and the mounting pad. All four mounting nuts of the pump were found only slightly more than finger tight and were removed with no resistance. The internal star locking washers were in place under the nuts and had been crushed indicating proper torque at one time. Standard torque on these nuts is 90" pounds. ## Factual narrative On July 21, 2003, approximately 1245 mountain daylight time, a Cessna 182S, N146NE, impacted the terrain during an attempted forced landing in a field near Henry's Lake, Idaho. The private pilot and his four passengers were not injured, but the aircraft, which is owned and operated by the pilot, sustained substantial damage. The 14 CFR Part 91 personal pleasure flight, which was en route to Pocatello, Idaho, departed Henry's Lake Airport about 10 minutes prior to the accident. No flight plan had been filed. The aircraft was being operated in visual meteorological conditions. According to the pilot, about five minutes after takeoff, the oil low pressure light illuminated and shortly thereafter he heard a knocking sound coming from the engine. He therefore shut the engine down and attempted to return to the airport of departure. Although he attempted to stretch his glide so that he could return to Henry's Lake Airport, he was unable to do so, and eventually had to make a power-off landing in a field about one mile from the runway. Although the touchdown was uneventful, during the landing roll, the aircraft encountered a ditch, which resulted in the separation of the nose gear and substantial damage to the aircraft structure. On July 22, 2003, a Federal Aviation Administration (FAA) Inspector from the Salt Lake City, Utah, Flight Standards District Office arrived at the accident site and inspected the aircraft. The inspector reported that oil residue was noted at the aft end of the engine around the accessory section. After the tail was lowered, a noticeable oil leak was noted around the vacuum pump flange (approximately 6 drops per minute). On August 7, 2003, another inspector from the FAA inspected the engine. The inspector reported that, "It was obvious the pneumatic pump gasket had failed..." and "...was blown out the top between the mating surfaces of the pump and the mounting pad." The inspector further reported that the four mounting nuts of the pump were only "slightly more than finger tight." All four nuts were removed with no resistance. The internal star locking washers were in place under the nuts and had been crushed. Standard torque on these nuts is 90" pounds. A review of maintenance records indicated that on October 23, 2002, at a tach time of 763.8 hours, Mandatory Lycoming Service Bulletin No. 554 was accomplished to replace the crankshaft gear retaining bolt. During this process, the removal of all accessories on the accessory housing was required. At the completion of the work, an engine test run was accomplished, as well as a leak check. No other maintenance had been accomplished on the engine except for an oil change on June 5, 2003. Approximately 116 hours had been accumulated on the engine at the time of the accident since the Service Bulletin accomplishment. The aircraft is equipped with four seats. The pilot reported that a three-year-old child was sharing a seat and seatbelt with the passenger in the left rear seat. ## Aircraft - Registration: [N146NE](https://openairdocs.org/aircraft/N146NE), registered now, S/N 18280221, built 1998 (OpenAirDocs) - Reported make and model: Cessna 182S - Registry model: [Cessna 182S](https://openairdocs.org/model/cessna-182s) (registry code 2072701) (OpenAirDocs) - Category: Airplane - Serial number: 18280221 - Airframe hours: 880 - Engines: Lycoming IO-540-AB1A5 230 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Michael L. Bartu - Registered owner: Idaho Rail Shop Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 1, 2002, 207 hours before - Departed: U53, Henry's Lake, ID - Destination: PIH, Pocatello, ID ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 27; injuries: none; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; last flight review October 10, 2001; seat: left; flight hours: 324 total, 230 in this make and model, 252 as pilot in command, 24 in the last 90 days, 16 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 90 °F ## 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 20030721015769A](https://openairdocs.org/incident/20030721015769A), Jul 21, 2003: Cessna 182S, Lake/Island Par, ID, Substantial damage. (-23) Pilot departed from Henry'S Lake Airport, ID, and about 5 minutes into the flight the "oil light" came on. The pilot turned around to return to Henry'S… 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.