# NTSB ANC05LA075: Piper PA-31-350, N3535F, Elim, AK, May 10, 2005 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 9, 2005, 16:45 local (May 10, 2005, 00:45 UTC) - Place: Elim, AK - Coordinates: 64.614723, -162.271667 - Nearby events: https://openairdocs.org/map.md?lat=64.6147&lon=-162.2717&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 7 uninjured - Status: Completed, report December 20, 2005 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA-AL FAI FSDO 01 - NTSB case key (mKey): 61462 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC05LA075 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/61462/pdf - Page: https://openairdocs.org/ntsb/ANC05LA075 ## Probable cause An improper installation of a fuel line fitting by company maintenance personnel, which resulted in a fuel leak and subsequent in-flight engine compartment fire during cruise flight that was discovered during the landing roll. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, cruise - fuel system,line fitting - leak (cause) - maintenance,installation - improper, company maintenance personnel (cause) - Fire, cruise - fluid,fuel - leak - engine compartment - fire ## Analysis During the landing roll of the 14 CFR Part 135 scheduled commuter flight, the airline transport certificated pilot noticed a fire in the right engine compartment. He pulled the firewall fuel shutoff for the right engine and stopped the airplane. The passengers were evacuated and the pilot discharged the airplane's fire extinguisher inside the right engine compartment. Additional dry chemical fire extinguishers were supplied by personnel at the airport, and the fire was extinguished. A passenger on the airplane reported that she smelled gasoline and smoke as the airplane was turning onto final, and saw flames as the plane landed. The airplane received structural damage to the right wing. An FAA inspector examined the airplane and reported that the fire pattern was consistent with an in-flight fire on the inboard side of the right engine, that appeared to be concentrated around the hydraulic pump, fuel pump, and the turbocharger. The inspector examined the fuel lines and hydraulic lines to the respective pumps. His examination revealed loose "B" nuts that had no heat discoloration. The airplane's hydraulic fluid reservoir contained fluid. The airplane's right engine hydraulic pump was replaced about 31 hours before the fire. The inspector interviewed the operator's maintenance personnel, and learned that during the hydraulic pump replacement, mechanics removed the right engine's fuel pump to access to the hydraulic pump. Due to the confined area during the reinstallation of the feeder line to the fuel pump, one mechanic held the line in-place, and another turned the fitting with a wrench. A leak check revealed that the fitting was cross-threaded and leaked. The fitting was re-tightened and signed off. The inspector sent the fuel lines and hydraulic lines to the NTSB IIC for examination. Each line was subjected to an air pressure leak test, and no leaks were discovered. ## Factual narrative On May 9, 2005, about 1645 Alaska daylight time, a wheel-equipped Piper PA-31-350 airplane, N3535F, sustained substantial damage as the result of an in-flight fire in the right engine during cruise flight between Nome, Alaska, and Elim, Alaska. The fire was detected by the pilot during the landing roll at Elim. The airplane was being operated as a visual flight rules (VFR) scheduled domestic passenger flight under Title 14, CFR Part 135, when the accident occurred. The airplane was operated as Flight 310, by Cape Smythe Air Service Inc., Barrow, Alaska. The airline transport certificated pilot, and the six passengers, were not injured. Visual meteorological conditions prevailed, and a VFR flight plan was filed. The flight originated at the Nome Airport, about 1605. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on May 10, the vice president of operations for the operator reported that when the fire was noticed by the pilot after landing at Elim, he pulled the firewall fuel shutoff for the right engine and stopped the airplane. The passengers were evacuated and the pilot discharged the airplane's fire extinguisher inside the right engine compartment. Additional dry chemical fire extinguishers were supplied by personnel at the airport, and the fire was extinguished. The airplane received structural damage to the right wing and right flap. A passenger on the airplane, who was seated in the aft, left seat, informed a Federal Aviation Administration (FAA) airworthiness inspector from the Fairbanks Flight Standards District Office (FSDO), that she "smelled gas and smoke as the airplane was turning into land (final approach). I saw flames as the plane landed, on the right side." The FAA inspector examined the airplane in Elim. He reported that the fire pattern was consistent with an in-flight fire on the inboard side of the right engine, that appeared to be concentrated around the hydraulic pump, fuel pump, and the turbocharger. The inspector examined the fuel lines and hydraulic lines to the respective pumps. His examination revealed loose "B" nuts that had no heat discoloration. The airplane's hydraulic fluid reservoir contained fluid. The inspector noted that the airplane's right engine hydraulic pump was replaced during a 50 hour inspection, about 31 hours before the fire. The inspector interviewed the operator's maintenance personnel, and learned that during the hydraulic pump replacement, mechanics removed the right engine's fuel pump to facilitate access to the hydraulic pump. Due to the confined area during the reinstallation of the feeder line to the fuel pump, one mechanic held the line in-place, and another turned the fitting with a wrench. A leak check revealed that the fitting was cross-threaded and leaked. The fitting was re-tightened and signed off. The inspector sent the fuel lines and hydraulic lines to the NTSB IIC for examination. Each line was subjected to an air pressure leak test at a local maintenance facility, and no leaks were discovered. According to the pilot, he completed a Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1) and sent it to the operator's corporate office in Barrow, Alaska. The operator was unable to locate the report, and the operator is now under new ownership. A copy of the pilot's statement, the FAA inspector's description of his findings, and a passenger statement, are included in the public docket for this report. ## Aircraft - Registration: [N3535F](https://openairdocs.org/deregistered/N3535F-2018-01-18), registration cancelled 2018-01-18, S/N 31-7952200, built 1979 (OpenAirDocs) - Reported make and model: Piper PA-31-350 - Registry model: [Piper PA-31-350](https://openairdocs.org/model/piper-pa-31-350) (registry code 7103110) (OpenAirDocs) - Registry engine: [Lycoming TI0-540 series](https://openairdocs.org/engine/lycoming-ti0-540-series) (registry code 41533, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 31-7952200 - Airframe hours: 23590 - Engines: Continental LTIO-540-J2B 350 horsepower reciprocating - Damage: Substantial damage - Fire: In-Flight - Flight: Part 135 - Registered owner: Cape Smythe Air Service Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, March 1, 2005, 84 hours before - Departed: PAOM, Nome, AK - Destination: ELI, Elim, AK - Flight plan: VFR - Airport: ELI, Elim, runway 01, 3,000 × 60 ft, gravel ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; injuries: none; airline transport, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; seat: left; flight hours: 8,250 total ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none ## 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 20050509007829A](https://openairdocs.org/incident/20050509007829A), May 9, 2005: Piper PA31350, Elim, AK, Substantial damage. (-23) [privacy data omitted] on 5/09/2005, a/c N3535F landed in Elim Alaska, @ approximately 1605HRS. During roll-out the pilot noticed fire coming from the #2… ## Other investigations on N3535F (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 ANC07LA059](https://openairdocs.org/ntsb/ANC07LA059), Jun 29, 2007: Piper PA-31 (N3535F), Kotzebue, AK, substantial damage. Probable cause: Locked parking brakes and the operator's maintenance personnel's failure to properly secure the parking brake cable at its fuselage attaching clamp. - [NTSB ANC02LA104](https://openairdocs.org/ntsb/ANC02LA104), Aug 24, 2002: Piper PA-31-350 (N3535F), Nuiqsut, AK, substantial damage. Probable cause: The pilot's inadvertent wheels-up landing. Factors contributing to the accident were the pilot's failure to complete the prelanding checklist, his diverted attention, and a delayed gear warning horn… 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.