# NTSB WPR21LA250: L-Bird CCX-2000, N10TA, Hood River, OR, June 28, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: June 28, 2021, 10:30 local (17:30 UTC) - Place: Hood River, OR - Coordinates: 45.672404, -121.56234 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.6724&lon=-121.5623&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 103360 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR21LA250 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103360/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103360 - Page: https://openairdocs.org/ntsb/WPR21LA250 ## Probable cause The total loss of engine power due to improper construction of the muffler, which resulted in separation of the internal components. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine exhaust: noise suppressor](https://openairdocs.org/ntsb-findings/01057820): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [L-Bird CCX-2000, 1 case](https://openairdocs.org/ntsb-findings/01057820/cases.md?model=05636XF), [All aircraft, 4 cases](https://openairdocs.org/ntsb-findings/01057820/cases.md) - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Effect on equipment; cases with it: [L-Bird CCX-2000, 1 case](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=05636XF), [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md) - [Engine exhaust](https://openairdocs.org/ntsb-findings/01057800): Aircraft › Aircraft power plant · Design (probable cause); cases with it: [L-Bird CCX-2000, 1 case](https://openairdocs.org/ntsb-findings/01057800/cases.md?model=05636XF), [All aircraft, 56 cases](https://openairdocs.org/ntsb-findings/01057800/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [L-Bird CCX-2000, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=05636XF), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing-landing roll: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490); cases with it: [L-Bird CCX-2000, 1 case](https://openairdocs.org/ntsb-events/490/sequence.md?model=05636XF), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The experimental, amateur-built airplane was retrofitted with an experimental exhaust system that comprised a titanium exhaust header and aluminum muffler. On the first flight with the new exhaust system, the engine lost total power just after takeoff. The pilot performed a forced landing during which the airplane impacted trees, resulting in substantial damage. Examination of the engine revealed that the muffler inner tube failed due to creep fatigue and fractured into several fragments. Components of the muffler included a perforated inner tube, surrounded by fiberglass packing material held in place by five clamps; an outer shell; end caps; and an inlet and exhaust tube, all constructed out of 6061-T6, an aluminum alloy not suited for use above 350°F to 400°F. Any use near or above that temperature will cause additional heat treatment and changes to the properties and performance of the material. The observation of the creep separation indicates that the material was exposed to much higher temperatures than this, likely between 600°F and 1000°F. It is likely that, when exposed to the hot exhaust gasses during takeoff, the fragments, clamps, and fiberglass packing material migrated aft and collapsed the remaining section of the inner tube, which plugged the exhaust port and resulted in a total loss of power. A postaccident test run of the engine without the muffler revealed no anomalies. ## Factual narrative On June 28, 2021, about 1030 Pacific daylight time, an experimental, amateur-built, CCX-2000 airplane, N10TA, was substantially damaged when it was involved in an accident near Hood River, Oregon. The pilot was not injured. The airplane was operated as a Title 14, Code of Federal Regulations Part 91 personal flight. The pilot was the director of maintenance for a maintenance facility contracted to perform work on the airplane. He reported that, at the request of the owner, the airplane was retrofitted with an experimental exhaust system designed to quiet the engine. The replacement exhaust system comprised a titanium exhaust header and an aluminum muffler. The pilot stated that, following the installation of the exhaust, an uneventful full-engine-power ground run was conducted. After the ground run, the pilot initiated the airplane’s first flight with the new exhaust system. Shortly after takeoff, the engine lost total power, and the pilot performed a forced landing to a field. During the landing roll, the airplane impacted trees before it came to rest upright in the field resulting in substantial damage to the rear spar carrythrough. A video recording of the takeoff revealed, about 24 seconds after takeoff, metallic shiny debris trailing from the airplane, as seen in figure 1. Figure 1: Airplane during takeoff. According to the manufacturer, the exhaust system was similar to a Carbon Cub design but with a header constructed out of titanium and a “Swiss style” muffler constructed out of aluminum. The manufacturer stated that the company had no trends with an aluminum muffler and stated this to the company requesting the design. The aluminum muffler was examined by the NTSB Materials Laboratory. Examination revealed that the muffler, as it was manufactured, comprised an inner cylindrical perforated hollow tube (approximately 2.5-inch diameter) surrounded by fiberglass packing material. The packing material was secured to the tube outer diameter by five band clamps and wire. This assembly was inserted into an approximate 3.5-inch diameter by 36-inch-long tube, which served as the outer shell of the muffler body. The packing material volume was sized to fill the volume between and nominally center the inner tube and outer shell. Designs of this type are sometimes referred to as “Swiss style” mufflers. End caps, an inlet tube, and an exhaust tube were then welded onto the assembly. The muffler inner tube, muffler shell, and inlet and exhaust tube were identified as 6061-T6, an aluminum alloy. The muffler inlet and exhaust tubes were sectioned from the muffler body. At the inlet end, the inner tube was fractured 360° around its circumference approximately 3.5 to 4.0 inches from the inlet end and the fiberglass packing had fallen inward, obstructing the view further inside the muffler. At the exhaust end, the inner tube had collapsed inward in three nominally symmetric segments, pinching the outlet end shut. (see figures 2 and 3.) Figure 2. Image ofthe muffler body inlet, showing the fractured perforated inner tube and the fiberglass packing that had fallen inward. Figure 3. Image of the muffler body outlet, showing the collapsed inner tube. The fracture features of the inner tube were consistent with a failure that started in tension near the 7 o’clock position and transitioned to bending as it progressed around both sides of the tube and terminated near the 1 o’clock position. The fractured ligaments, when viewed under magnification, had a specular appearance with no apparent crack growth features that would be typical of fatigue or overstress fractures. The ligament fractures were examined in a scanning electron microscope equipped with an energy-dispersive X-ray spectrometer (EDS). The observations were consistent with a high-temperature creep separation/fracture. According to the Federal Aviation Administration, a postaccident test run of the engine without the aluminum muffler revealed that the engine started easily and responded well to throttle and propeller control adjustments. There were no issues noted during the engine run, and no mechanical malfunctions or failures that would have precluded normal operation. ## Aircraft - Registration: [N10TA](https://openairdocs.org/aircraft/N10TA), registered now, S/N CCX-2000-0080, built 2019 (OpenAirDocs) - Reported make and model: L-BIRD LLC CCX-2000 - Registry model: [L-Bird CCX-2000](https://openairdocs.org/model/l-bird-ccx-2000) (registry code 05636XF) (OpenAirDocs) - Registry engine: [Lycoming CC363I](https://openairdocs.org/engine/lycoming-cc363i) (registry code 41465, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: CCX-2000-0080 - Year built: 2019 - Airframe hours: 127.1 - Engines: LYCOMING CC363I 187 horsepower reciprocating - Damage: Substantial damage - Flight: Flight test, Part 91 - Operator: TACAero - Registered owner: Flight Management LLC - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, December 2, 2020 - Destination: Same as departure - Airport: 4S2, Ken Jernstedt Airfield, runway 25, 3,040 × 74 ft, asphalt - Equipment: Electronic primary flight display, Angle of attack indicator, ADS-B, Stall warning system, Onboard weather, Satellite tracking device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 25; injuries: none; commercial; airplane ratings: single-engine land; medical: class 2, without waivers/limitations; last flight review June 30, 2019; seat: front; restraint: 4-point; flight hours: 2,100 total, 450 in this make and model, 1,950 as pilot in command, 60 in the last 90 days, 40 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 330° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 93 °F, dew point 57 °F - Altimeter: 29.79 inHg - Icing: Unknown - Turbulence: Unknown - Observed at: K4S2, 1 nm away - METAR: K4S2 281735Z AUTO 33003KT 10SM CLR 34/14 A2979 RMK AO2 ## 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 20210628011039A](https://openairdocs.org/incident/20210628011039A), Jun 28, 2021: L-Bird LLC CCX-2000, Hood River, OR, Substantial damage. Prior to takeoff pilot ran engine on aircraft for approximately 20 minutes. Aircraft was shut down. Pilot started aircraft and performed full run-up procedure.… ## Docket (8 files) The files NTSB released with the investigation on February 28, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103360. 31.3 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 15 pages, 310 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13061647&FileExtension=pdf&FileName=NTSB%20Form%206120_1_Redacted-Rel.pdf - Materials laboratory factual report 21-102 (item 2, PDF, 10 pages, 14 photos, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13055655&FileExtension=pdf&FileName=Materials%20Laboratory%20Factual%20Report%2021-102-Rel.pdf - Memo for record engine test run (item 3, PDF, 1 page, 151 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13062158&FileExtension=pdf&FileName=Memo%20for%20Record%20FAA%20Report%20on%20Engine%20Run-Rel.pdf - Pilot's statement (item 4, PDF, 2 pages, 129 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13062720&FileExtension=pdf&FileName=Memo%20for%20Record%20Pilot%20Statement%20WPR21LA250-Rel.pdf - Memo of record (item 5, PDF, 1 page, 138 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15001890&FileExtension=pdf&FileName=Memo%20for%20Record%20Experimental%20Aircraft%20Exhaust%20INC%20Interview-Rel.pdf - Invoices from exhaust manufacturer (item 6, PDF, 5 pages, 140 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13062504&FileExtension=pdf&FileName=Invoices%20from%20Experimental%20Aircraft%20Exhaust_INC_Redacted-Rel.pdf - Video file (item 7, MOV, 27.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15050085&FileExtension=MOV&FileName=IMG_4062-Rel.MOV - Photos (item 8, PDF, 3 pages, 693 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15050149&FileExtension=pdf&FileName=WPR21LA250%20Photos-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.