# NTSB CHI02LA242: Rare Waco T-10, N98TW, Omaha, NE, August 10, 2002 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 10, 2002, 17:00 local (22:00 UTC) - Place: Omaha, NE - Coordinates: 41.195835, -96.11222 - Nearby events: https://openairdocs.org/map.md?lat=41.1958&lon=-96.1122&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report November 25, 2003 - Report: Approved by Office Director - Parties: FAA-Lincoln FSDO - NTSB case key (mKey): 55496 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI02LA242 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/55496/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=55496 - Page: https://openairdocs.org/ntsb/CHI02LA242 ## Probable cause The partial loss of engine power due to fuel starvation as a result of a restricted fuel line, and the unsuitable terrain for landing encountered by the pilot. A contributing factor was the bean field. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, cruise - fuel system,line - blocked(partial) (cause) - fuel system - starvation (cause) - Forced landing, emergency descent/landing - On ground/water encounter with terrain/water, emergency descent/landing - unsuitable terrain or takeoff/landing/taxi area - encountered, pilot in command (cause) - terrain condition - crop (contributing factor) ## Analysis The experimental airplane sustained substantial damage during a forced landing to a bean field after a partial loss of engine power during cruise flight. The pilot reported he was flying at 2,400 feet mean sea level when the engine began to run sporadically with large fuel pressure fluctuations. Attempts to restore engine power failed and the pilot executed a forced landing. The inspection of the airplane's flight controls and engine controls revealed continuity with no anomalies. The inspection revealed that the engine driven fuel pump, throttle body, fuel nozzles, fuel flow divider, electric fuel pump, and the magnetos were in good operating condition. A fuel sample was tested and it tested in the normal range with no contamination. During the inspection of the fuel system, approximately one and a half gallons were drained from the quick drain at the bottom of the fuselage before the fuel "slowed to a dribble." The inspection revealed that two drilled-out rivet heads were restricting the fuel line between the main fuel tank and the header tank. Approximately 19 gallons of fuel were drained from the main fuel tank. The inspection revealed that the tank did not have a finger screen installed at the outlet port. The two drilled out rivet heads found in the fuel line had not been used in the construction of the fuel tank and were foreign to the fuel system. The engine was removed from the airframe for an engine run. The engine operated normally at idle power and at full power during the engine run. ## Factual narrative On August 10, 2002, at 1700 central daylight time, a Rare Aircraft WACO T-10, N98TW, sustained substantial damage during a forced landing to a bean field, located about 10 miles southeast of Omaha, Nebraska, after a partial loss of engine power during cruise flight. The commercial pilot and two passengers were not injured. The 14 CFR Part 91 flight departed Millard Airport (MLE), Omaha, Nebraska, at 1630 with Wahoo Municipal Airport (AHQ), Wahoo, Nebraska, as the intended destination. Visual meteorological conditions existed at time of the accident. No flight plan was filed. The pilot reported he was flying at 2,400 feet mean sea level when the engine began to run sporadically. The pilot reported large fuel pressure fluctuations. The pilot's attempts to restore engine power failed. The pilot executed a forced landing to a soybean field. The left landing gear became entangled in the beans and the airplane spun about 190 degrees. A Federal Aviation Administration (FAA) airworthiness inspector examined the airplane at the Wahoo Municipal Airport. The inspector reported that all flight controls and engine controls exhibited continuity. He tested the fuel system for pressure from the electrical boost pump and it was found to have "adequate pressure" at the throttle body intake port. All fuel nozzles were removed and tested for fuel flow and no anomalies were found. The inspector reported that the engine driven fuel pump, throttle body, fuel nozzles, fuel flow divider, electric fuel pump, and the magnetos were checked and were found to be in "good operating condition." Approximately one gallon of fuel was drained from the lower sump (header tank) fuel line drain valve. It was tested at a laboratory and the lab analysis revealed that the fuel tested in the normal range with no contamination. The FAA inspector reported that the airplane's fuel tank was drained to prepare the airplane for shipment to a repair facility. He reported that approximately one and a half gallons were drained from the quick drain at the bottom of the fuselage before the fuel "slowed to a dribble." The inspector examined the fuel lines back to the main fuel tank to find the blockage, and he found the line from the main fuel tank to the header tank restricted. He reported that he removed the fuel line and found two drilled-out rivet heads in the fuel line. He reported that 19 gallons of fuel were drained from the main fuel tank. An inspection of the fuel tank revealed that there were numerous rivet bucktails in the bottom of the tank. The inspection revealed that the tank did not have a finger screen installed at the outlet port. An inspection of the fuel tank revealed that 12 rivets had sheared from the fuel baffles inside the fuel tank. Eleven rivet bucktails were found in the bottom of the tank. The two drilled out rivet heads found in the fuel line had not been used in the construction of the fuel tank and were foreign to the fuel system. The engine, a Jacobs R755-B2 with an Aeroflow fuel injection system installed, was removed from the airframe and shipped to the engine manufacturer for an engine run. The FAA Principal Maintenance Inspector who oversaw the engine run reported that the engine operated smoothly at idle power. He reported the engine was operated to full power after warm up, and the engine operated normally. ## Aircraft - Registration: [N98TW](https://openairdocs.org/aircraft/N98TW), registered now, S/N 2502, built 1999 (OpenAirDocs) - Reported make and model: Rare Aircraft WACO T-10 - Registry model: [Rare TAPERWING T-10](https://openairdocs.org/model/rare-taperwing-t-10) (registry code 05605BW) (OpenAirDocs) - Registry engine: [Jacobs R755B series](https://openairdocs.org/engine/jacobs-r755b-series) (registry code 35007, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 2502 - Engines: Jacobs R-755B2 275 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: William L. Gottenberg - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, May 30, 2002 - Departed: MLE, Omaha, NE - Destination: AHQ, Wahoo, NE ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 41; injuries: none; flight engineer, airline transport, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; last flight review April 30, 2002; seat: rear; flight hours: 10,107 total, 40 in this make and model, 135 in the last 90 days, 47 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 90 °F, dew point 64 °F - Altimeter: 30.07 inHg ## 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 20020810027789A](https://openairdocs.org/incident/20020810027789A), Aug 10, 2002: Amtr NUWACOT10, Valley, NE, Substantial damage. (-23) Pilot and two passengers departed wahoo, NE (ahq), approximately 1535 hours local. Pilot performed a full stop landing at millard, NE (mle), then took… ## Docket (22 files) The files NTSB released with the investigation on October 16, 2003, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=55496. 4.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 430 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40469760&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Record of Interview (item 2, .PDF, 72 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40469764&FileExtension=.PDF&FileName=Record%20of%20Interview-Master.PDF - FAA Inspector's Report (item 3, .PDF, 75 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198474&FileExtension=.PDF&FileName=FAA%20Inspector%27s%20Report-Master.PDF - FAA Airworthiness Inspector's Report (item 4, .PDF, 126 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198475&FileExtension=.PDF&FileName=FAA%20Airworthiness%20Inspector%27s%20Report-Master.PDF - FAA PMI's Engine Test Run Report (item 5, .PDF, 39 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198476&FileExtension=.PDF&FileName=FAA%20PMI%27s%20Engine%20Test%20Run%20Report-Master.PDF - Metal Fuel Tank Fabrication Details (item 6, .PDF, 42 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198477&FileExtension=.PDF&FileName=Metal%20Fuel%20Tank%20Fabrication%20Details-Master.PDF - T-10 Fuel System Schematic (item 7, .PDF, 23 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198478&FileExtension=.PDF&FileName=T-10%20Fuel%20System%20Schematic-Master.PDF - Excerpts From Aircraft Logbooks (item 8, .PDF, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40469762&FileExtension=.PDF&FileName=Excerpts%20From%20Aircraft%20Logbooks-Master.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 9, .PDF, 263 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40469763&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-Master.PDF - Photo 1. Fuselage (item 10, .PDF, 163 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198494&FileExtension=.PDF&FileName=Photo%201.%20%20Fuselage-Master.PDF - Photo 2. Aircraft Name Plate (item 11, .PDF, 173 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198495&FileExtension=.PDF&FileName=Photo%202.%20%20Aircraft%20Name%20Plate-Master.PDF - Photo 3. Front of Tank (item 12, .PDF, 166 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198496&FileExtension=.PDF&FileName=Photo%203.%20%20Front%20of%20Tank-Master.PDF - Photo 4. Header Tank (item 13, .PDF, 156 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198497&FileExtension=.PDF&FileName=Photo%204.%20%20Header%20Tank-Master.PDF - Photo 5. Restricted Fuel Line at the Bottom of the Main Tank (item 14, .PDF, 72 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198498&FileExtension=.PDF&FileName=Photo%205.%20%20Restricted%20Fuel%20Line%20at%20the%20Bottom%20of%20the%20Main%20Tank-Master.PDF - Photo 6. Header Tank (item 15, .PDF, 71 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198499&FileExtension=.PDF&FileName=Photo%206.%20%20Header%20Tank-Master.PDF - Photo 7. Side View of Header Tank (item 16, .PDF, 74 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198500&FileExtension=.PDF&FileName=Photo%207.%20%20Side%20View%20of%20Header%20Tank-Master.PDF - Photo 8. View of Restricted Line (item 17, .PDF, 57 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198501&FileExtension=.PDF&FileName=Photo%208.%20%20View%20of%20Restricted%20Line-Master.PDF - Photo 9. Restricted Line and the Elbow at the Header Tank (item 18, .PDF, 63 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198502&FileExtension=.PDF&FileName=Photo%209.%20%20Restricted%20Line%20and%20the%20Elbow%20at%20the%20Header%20Tank-Master.PDF - Photo 10. Bottom of the Main Tank (item 19, .PDF, 69 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198503&FileExtension=.PDF&FileName=Photo%2010.%20%20Bottom%20of%20the%20Main%20Tank-Master.PDF - Photo 11. Rivets Found in the Fuel Line (item 20, .PDF, 53 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198504&FileExtension=.PDF&FileName=Photo%2011.%20%20Rivets%20Found%20in%20the%20Fuel%20Line-Master.PDF - Photo 12. Inside View of Main Tank (item 21, .PDF, 226 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198505&FileExtension=.PDF&FileName=Photo%2012.%20%20Inside%20View%20of%20Main%20Tank-Master.PDF - Photo 13. 11 Rivet Buck Tails and 2 Drilled-Out Rivets (item 22, .PDF, 221 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40198506&FileExtension=.PDF&FileName=Photo%2013.%20%2011%20Rivet%20Buck%20Tails%20and%202%20Drilled-Out%20Rivets-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.