# NTSB CEN17LA357: Beech A36, N18403, McAlester, OK, September 15, 2017 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: September 15, 2017, 16:20 local (21:20 UTC) - Place: McAlester, OK - Coordinates: 34.871944, -95.78778 - Nearby events: https://openairdocs.org/map.md?lat=34.8719&lon=-95.7878&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report April 8, 2019 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Continental Motors, FAA - NTSB case key (mKey): 96031 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN17LA357 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/96031/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=96031 - Page: https://openairdocs.org/ntsb/CEN17LA357 ## Probable cause A total loss of engine power for reasons that could not be determined because postaccident examination of the engine did not reveal any evidence of mechanical malfunctions or failures that would have precluded normal operation. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Beech A36, 23 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=1151604), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) - [Object/animal/substance](https://openairdocs.org/ntsb-findings/03022000): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Beech A36, 2 cases](https://openairdocs.org/ntsb-findings/03022000/cases.md?model=1151604), [All aircraft, 224 cases](https://openairdocs.org/ntsb-findings/03022000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Beech A36, 56 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=1151604), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing-flare/touchdown: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Beech A36, 7 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=1151604), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Beech A36, 78 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=1151604), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The private pilot stated that the flight originated with full fuel tanks. About 8 minutes after takeoff, he noticed fuel leaking from the left fuel tank cap for a short period. The pilot continued the flight, switching fuel tanks every 25 minutes. The flight continued uneventfully until the engine lost total power while the airplane was entering the downwind leg to land. The pilot switched fuel tanks and attempted to restart the engine to no avail. The pilot performed a forced landing in a field; the airplane touched down hard and contacted a hay bale, which resulted in substantial damage to the wings and compromised the fuel system. Postaccident examination of the main fuel tank caps revealed the O-rings were cracked. Maintenance records showed that the O-rings were replaced about 17 months before the accident. Although it is unknown how much fuel leaked from the fuel cap during the flight, the pilot reported that, about 50 minutes before the accident, both fuel tanks were indicating about 3/4 full; thus, it is doubtful that enough fuel would have leaked to result in fuel exhaustion. A postaccident engine test run was conducted with the fuselage strapped down on a trailer; an alternate fuel system was rigged to both the left and right fuel inlet lines at the fuselage. The engine started without hesitation and ran smoothly up to 1,500 rpm using the left fuel tank inlet. The test was repeated using the right fuel tank inlet, and the engine performed in the same manner. The rpm was not increased any higher due to the security of the fuselage during the test. Postaccident examination of the engine did not reveal evidence of preimpact malfunctions or failures that would have precluded normal operation; thus, the reason for the loss of engine power could not be determined. ## Factual narrative On September 15, 2017, at 1615 central daylight time, a Beech A36 airplane, N18403, collided with a hay bale during a forced landing following a loss of engine power while on approach to the McAlester Regional Airport (MLC), McAlester, Oklahoma. The private pilot received minor injuries. The airplane was substantially damaged. The airplane was registered to Travel Air LLC and was being operated by the pilot as a 14 Code of Federal Regulations Part 91 personal flight. Visual flight rules conditions existed near the accident site at the time of the accident. The pilot had canceled his instrument flight rules flight plan when he had MLC in sight. The flight departed from the Garner file Airport (UVA), Uvalde, Texas, at 1357.The pilot reported he purchased fuel prior to takeoff and that both main fuel tanks and both tip tanks were full. The pilot stated he selected the right fuel tank for takeoff and used a stop watch to switch the fuel tanks every 25 minutes during the flight. About 8 minutes after takeoff, while climbing through 5,000 ft, the pilot noticed fuel leaking from the left fuel tank filler cap for a short period. He continued the flight which was uneventful until he prepared to enter a downwind leg at MLC which was when the engine lost power. The pilot switched fuel tanks and attempted to restart the engine to no avail. The pilot stated he touched down hard during the off airport forced landing. Both main landing gear were pushed up through the wings and the right wing contacted a hay bale. The left wing remained attached to the fuselage. The right tip tank was separated from the right wing which remained connected to the fuselage by the control cables and wiring. The fuel system was compromised due to impact damage. A postaccident examination of the wreckage was conducted on October 24, 2017. Both wings were detached from the airframe and were stored outside. Both fuel caps were removed, inspected, and found to have cracks in the main O-ring seal. The left fuel cap was tested in place, by applying air pressure to the fuel outlet line and plugging the vent system and tip tank fuel inlet. A soap and water solution placed around the cap bubbled up indicating an air leak. Air could be felt escaping from around the fuel cap outer seal and the center seal. The right wing was not tested due to impact damage. The aircraft logbook shows that the fuel cap O-rings were replaced with new O-rings during the annual inspection on April 1, 2016. The engine, which was not damaged, had been converted from an IO-520 per STC SE10746SC. A borescope was used to examine the piston domes, cylinder walls, and valve faces which exhibited normal wear and combustion deposits. The propeller was damaged during the accident. The extent of the damage precluded using the accident propeller during the engine run. The propeller was removed, and slave propeller was installed on the airplane. The top spark plugs appeared to be normal in wear and color. The plugs were thenreinstalled in the engine. The airframe was secured on a flatbed trailer. An alternate fuel system was rigged to the left fuel wing fuel inlet line at the fuselage. The fuel line going into the JPI fuel flow transducer was disconnected, power was applied to the airplane and the fuel system boost pump was turned on until positive fuel flow at the disconnected line was verified. The line was then reconnected. The engine started on the first attempt and was idled between 600 – 700 rpm to confirm oil pressure and fuel flow. The rpm was increased to 1,000 rpm. The engine power was then increased to 1,500 rpm and a magneto check was performed. The rpm drop for each magneto during the check was 60 to 80 rpm. The engine run was limited to 1,500 rpm due to the security of the fuselage on the trailer. The above process was repeated with an alternate fuel supply rigged to the right-wing fuel inlet line. The engine run results were the same. With the engine running 1,500 rpm, the fuel selector was switched to the off position. The engine ran for about 25 seconds prior to it shutting down. Examination of the engine revealed the engine started and ran smoothly as tested up to 1,500 rpm. The airplane was equipped with a JPI FS-450 which monitored fuel flow, fuel used, and fuel remaining. The unit was removed from the airplane and shipped to the National Transportation Vehicle Recorder Division for examination. The device stores the last remaining record of fuel used and fuel remaining in gallons. It does not show which fuel tank contains the remaining fuel. A power supply was attached to the unit and the unit display showed 45.4 gallons of fuel used, and 66.6 gallons of fuel remaining. These amounts do not take into consideration the unknown amount of fuel that leaked from the left fuel tank filler cap. The pilot reported that at 1524, both fuel tanks were indicating about ¾ full. ## Aircraft - Registration: [N18403](https://openairdocs.org/aircraft/N18403), registered now, S/N E-1120, built 1977 (OpenAirDocs) - Reported make and model: BEECH A36 - Registry model: [Beech A36](https://openairdocs.org/model/beech-a36) (registry code 1151604) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: E-1120 - Year built: 1977 - Airframe hours: 2515 - Engines: Continental IO-520-BB 300 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 16, 2017, 15 hours before - Departed: UVA, Uvalde, TX - Destination: MLC, McAlister, OK - Flight plan: IFR - Airport: MLC, McAlester Regional Airport - Equipment: Auto-pilot, Electronic multifunction display, Electronic primary flight display, Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 42; injuries: minor; private; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, without waivers/limitations; last flight review September 7, 2017; seat: left; restraint: 3-point; flight hours: 508 total, 72 in this make and model, 326 as pilot in command, 47 in the last 90 days, 9 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 160° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 90 °F, dew point 66 °F - Altimeter: 29.87 inHg - Observed at: MLC, 1 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 20170915024389A](https://openairdocs.org/incident/20170915024389A), Sep 15, 2017: Beech A36, Mcalister, OK, Substantial damage. Pilot was inbound for runway 20 at mcl and had desended to FL1400 AGL when he experienced a loss of power. Pilot then attempted to land on runway 2. About 200… ## Docket (11 files) The files NTSB released with the investigation on December 6, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=96031. 108 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 5.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=7069775&FileExtension=pdf&FileName=1%20-%206120_Redacted-Rel.pdf - Airframe and engine exam (item 2, PDF, 4 pages, 76 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=7069869&FileExtension=pdf&FileName=2%20-%20NTSB%20Airframe%20and%20Engine%20Exam-Rel.pdf - Engine monitor - specialist's factual report (item 3, PDF, 1 page, 15 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=5673519&FileExtension=pdf&FileName=cen17la357_no_data_v0-Rel.pdf - Fuel flow monitor - specialist's factual report (item 4, PDF, 2 pages, 171 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=5745833&FileExtension=pdf&FileName=cen17la357%20jpi%20fs450%20report-Rel.pdf - Record of conversation (item 5, PDF, 2 pages, 81 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=7069676&FileExtension=pdf&FileName=5%20-%20Record%20of%20Conversation%20-%20Pilot-Rel.pdf - Aircraft logbook entry (item 6, PDF, 1 page, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=7069558&FileExtension=pdf&FileName=6%20-%20Logbook%20Page_Redacted-Rel.pdf - Fuel receipt (item 7, PDF, 1 page, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=7069957&FileExtension=pdf&FileName=7%20-%20Fuel%20Receipt_Redacted-Rel.pdf - Statement of party representatives to NTSB investigation (item 8, PDF, 3 pages, 4.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=7069359&FileExtension=pdf&FileName=8%20-%20Party%20Forms_Redacted-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 9, PDF, 1 page, 63 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=7070120&FileExtension=pdf&FileName=9%20-%20WRECKAGE%20RELEASE%20a_Redacted-Rel.pdf - Video (item 10, MOV, 90.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=7142021&FileExtension=mov&FileName=2017-09-15%2014.05.39-Rel.mov - Photos (item 11, PDF, 5 pages, 5 photos, 3.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=7081155&FileExtension=pdf&FileName=Photo%20Array-Rel.pdf 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.