# NTSB ERA09LA266: Douglas DC3, N136FS, San Juan, PR, April 26, 2009 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: April 26, 2009, 04:15 local (08:15 UTC) - Place: San Juan, PR - Coordinates: 18.439443, -66.001945 - Nearby events: https://openairdocs.org/map.md?lat=18.4394&lon=-66.0019&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Defining event: [Taxi-to runway: Fire/smoke (non-impact)](https://openairdocs.org/ntsb-events/150) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report November 9, 2009 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 73730 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA09LA266 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/73730/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=73730 - Page: https://openairdocs.org/ntsb/ERA09LA266 ## Probable cause Worn electrical wires and a fuel pressure indicating system hose, which resulted in a ground fire during taxi. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Electrical power system](https://openairdocs.org/ntsb-findings/01022400): Aircraft › Aircraft systems · Damaged/degraded (probable cause); cases with it: [Douglas DC3, 1 case](https://openairdocs.org/ntsb-findings/01022400/cases.md?model=3021401), [All aircraft, 48 cases](https://openairdocs.org/ntsb-findings/01022400/cases.md) - [Fuel system: fuel indication system](https://openairdocs.org/ntsb-findings/01022840): Aircraft › Aircraft systems · Damaged/degraded (probable cause); cases with it: [Douglas DC3, 1 case](https://openairdocs.org/ntsb-findings/01022840/cases.md?model=3021401), [All aircraft, 30 cases](https://openairdocs.org/ntsb-findings/01022840/cases.md) - [Misc hardware: hoses and tubes](https://openairdocs.org/ntsb-findings/01071410): Aircraft › Fluids/misc hardware · Not specified; cases with it: [Douglas DC3, 1 case](https://openairdocs.org/ntsb-findings/01071410/cases.md?model=3021401), [All aircraft, 40 cases](https://openairdocs.org/ntsb-findings/01071410/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Taxi-to runway: Fire/smoke (non-impact)](https://openairdocs.org/ntsb-events/150) (defining event); cases with it: [Douglas DC3, 1 case](https://openairdocs.org/ntsb-events/150/sequence.md?model=3021401), [All aircraft, 504 cases](https://openairdocs.org/ntsb-events/150/sequence.md) ## Analysis During taxi to a runway, the instrument panel and cockpit floor erupted in flames. Examination of the wreckage revealed that the majority of the wires contained inside the main junction box had very little damage except for two wires that had insulation missing. The damage appeared to be associated with the routing of the two wires. Both wires were connected to the battery relay and ran through wires in and around the exposed terminal studs. Heat damage was noted on the insulation of wires and other components that were in contact with the exposed wires. The wires ran from the battery relay to the forward section of the cockpit, where the fire started. Due to the fire damage that consumed the cockpit, the examination was unable to determine what system the wires were associated with. Further examination revealed that the fuel pressure was a direct indicating system. Fuel traveled directly to the instruments in the cockpit via rigid aluminum lines routed on the right lower side of the fuselage, where more severe fire damage was noted. Review of maintenance records did not reveal any evidence of the fuel pressure indicating system lines and hoses having ever been replaced; however, they were only required to be replaced on an as-needed basis. The electrical system, instrument lines, and hoses through the nose compartment were required to be inspected on a Phase D inspection; the airplane's last Phase D inspection was completed about 9 months prior to the accident and the airplane had accrued 313.1 hours of operation since that inspection. ## Factual narrative On April 26, 2009, about 0415 eastern daylight time, a Douglas DC3, N136FS, operated by Four Star Aviation Inc., was substantially damaged after experiencing a cockpit fire during taxi at Luis Munoz Marin International Airport (TJSJ), San Juan, Puerto Rico. The certificated airline transport pilot, certificated commercial pilot, and two crewmembers were not injured. Visual meteorological conditions prevailed for the planned flight to Cyril E King Airport (TIST), Charlotte Amalie, United States Virgin Islands. A company flight plan was filed for the cargo flight conducted under the provisions of 14 Code of Federal Regulations Part 135. The flightcrew reported that they were transporting mail. While taxing on "juliet" taxiway to runway 10, the instrument panel and cockpit floor erupted in flames while smoke filled the cockpit. As the pilots were shutting down the engines, they became overwhelmed with fire and smoke, and quickly exited the airplane along with the two cargo handlers. The flightcrew added that they did not note any abnormal instrument readings or any anomalies during preflight inspection. The low-wing, tailwheel retractable-gear airplane, serial number 22405, was manufactured in 1942. It was powered by two Pratt and Whitney R-1830-90D, 1,200-horsepower engines. At the time of the accident, it was equipped with five seats due to a cargo configuration. The airplane had accumulated 19,952 total hours of operation at the time of the accident. Examination of the wreckage by Federal Aviation Administration (FAA) inspectors revealed that the fire was intense, from the bulkhead behind the pilots’ seats, to the front of the airplane. Everything was melted in that area, including instruments, switches, tubing, hoses, and skin. The inspectors noted more damage on the right side of the fuselage. They also noted that the left propeller was partially feathered. The inspectors observed that the majority of the wires, contained inside the main junction box, had very little damage, except for two wires that had insulation missing. The damage appeared to be associated with the routing of the two wires. Both wires were connected to the battery relay and they ran through wires in and around the exposed terminal studs. Heat damage was noted on the insulation of wires and other components that were in contact with the exposed wires. The wires ran from the battery relay to the forward section of the cockpit, where the fire started. Due to the fire damage, the inspectors were unable to determine what system the wires were associated with; however, one of the systems connected to the battery relay is the propeller feathering system. The inspectors added that the fuel pressure was a direct indicating system. Fuel traveled directly to the instruments via rigid aluminum lines routed on the right lower side of the fuselage. Review of maintenance records by the FAA inspectors revealed that the airplane was maintained under an FAA Approved Airplane InspectionProgram. The review did not reveal any evidence of the fuel pressure indicating system lines and hoses having ever been replaced; however, they were only required to be replaced on an as needed basis. Further review of maintenance records revealed that the electrical system, instrument lines, and hoses through the nose compartment were required to be inspected on a Phase D inspection. The airplane's last Phase D inspection was completed on July 14, 2008. The airplane had accrued 313.1 hours of operation, from the time of the last Phase D inspection, until the fire. The airplane's most recent inspection was a Phase B inspection, which was completed on March 22, 2009. The airplane had accumulated 40 hours of operation since that inspection. Review of the National Transportation Safety Board accident/incident database, and FAA service difficulty reports, did not reveal any similar events during the 5-year period preceding the accident. ## Aircraft - Registration: [N136FS](https://openairdocs.org/deregistered/N136FS-2018-03-09), registration cancelled 2018-03-09, S/N 24405, built 1942 (OpenAirDocs) - Reported make and model: DOUGLAS DC3 - Registry model: [Douglas DC3](https://openairdocs.org/model/douglas-dc3) (registry code 3021401) (OpenAirDocs) - Registry engine: [Pratt & Whitney R-1830 series](https://openairdocs.org/engine/pratt-whitney-r-1830-series) (registry code 52020, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 24405 - Airframe hours: 19952 - Engines: P & W R-1830-90D 1350 horsepower reciprocating; P & W R-1830-90D 1350 horsepower reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Part 135 - Operator: Four Star Aviation Inc - Registered owner: Four Star Aviation Inc - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, March 22, 2009, 40 hours before - Departed: TJSJ, San Juan, PR - Destination: TIST, Charlotte Amali - Flight plan: Company VFR - Airport: TJSJ, Luis Munoz Marin International ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 69; injuries: none; commercial, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review December 28, 2008; seat: left; flight hours: 50,233 total, 7,000 in this make and model, 48,800 as pilot in command, 150 in the last 90 days, 50 in the last 30 days, 0 in the last 24 hours - Co-pilot; age 29; injuries: none; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review October 22, 2008; seat: right; flight hours: 957 total, 204 in this make and model, 650 as pilot in command, 100 in the last 90 days, 24 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night - Wind: 100° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 70 °F - Altimeter: 30.04 inHg - Observed at: TJSJ ## Docket (4 files) The files NTSB released with the investigation on June 26, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=73730. 1.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40314307&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Weather Report (item 2, .PDF, 13 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40314309&FileExtension=.PDF&FileName=Weather%20Report-Master.PDF - Statement From FAA Inspector (item 3, .PDF, 20 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40314312&FileExtension=.PDF&FileName=Statement%20From%20FAA%20Inspector-Redacted.PDF - Photo - Wreckage (Courtesy of FAA) (item 4, .PDF, 215 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40314313&FileExtension=.PDF&FileName=Photo%20-%20Wreckage%20(Courtesy%20of%20FAA)-Master.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.