# NTSB WPR20LA180: Bellanca 7KCAB, N36339, Renton, WA, June 12, 2020 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: June 12, 2020, 10:00 local (17:00 UTC) - Place: Renton, WA - Coordinates: 47.488334, -122.21221 - Nearby events: https://openairdocs.org/map.md?lat=47.4883&lon=-122.2122&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: Minor injuries - Injuries: 2 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 101432 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR20LA180 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101432/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101432 - Page: https://openairdocs.org/ntsb/WPR20LA180 ## Probable cause Maintenance personnel’s inadequate post-maintenance inspections that resulted in the total loss of engine power due to a blockage in the air intake. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Power plant: air intake](https://openairdocs.org/ntsb-findings/01057160): Aircraft › Aircraft power plant · Inadequate inspection (probable cause); cases with it: [Bellanca 7KCAB, 1 case](https://openairdocs.org/ntsb-findings/01057160/cases.md?model=1220701), [All aircraft, 50 cases](https://openairdocs.org/ntsb-findings/01057160/cases.md) - [Maintenance](https://openairdocs.org/ntsb-findings/02062000): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Bellanca 7KCAB, 1 case](https://openairdocs.org/ntsb-findings/02062000/cases.md?model=1220701), [All aircraft, 143 cases](https://openairdocs.org/ntsb-findings/02062000/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: [Bellanca 7KCAB, 3 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=1220701), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) ## Analysis The airplane had recently undergone an annual inspection, and the accident flight was the first flight since being out of maintenance. After making a normal departure and touch-and-go landing, the pilot receiving instruction applied full power. As the airplane reached an altitude of about 400 feet above ground level (agl), the engine abruptly stopped producing (total) power. The airplane could not maintain level altitude and during the subsequent off-airport landing, the airplane was substantially damaged when it collided with a tree. Postaccident examination revealed that the air induction box contained a piece of bunched up paper that likely restricted the inlet cavity. As part of the annual inspection, a repair person completed a small fiberglass patch and painting on the lower cowling. He could not recall the specific repair on the airplane but said he often placed paper in the induction to prevent debris from entering the engine. After the maintenance, the airplane sat for a day with the lower cowling not fastened but maintenance personnel did not recognize the blockage. They also did not find the paper during the post-maintenance inspections and returned the airplane into service with an unsafe condition. ## Factual narrative On June 12, 2020, about 1000 Pacific daylight time, a Bellanca 7KCAB Citabria airplane, N36339, was substantially damaged when it was involved in an accident near Renton, Washington. The certified flight instructor (CFI) and pilot receiving instruction sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The airplane had recently undergone an annual inspection and the accident flight was the first flight since being out of maintenance. The operator, Boeing Employees Flying Association, required that a test flight be performed following annual inspections and the CFI was authorized to perform those flights. The CFI elected to take the pilot receiving instruction for the test flight since she was working on obtaining her tailwheel endorsement. The test flight protocol provided an extended checklist including an elongated preflight and runup. The CFI added 10 gallons of fuel in each wing tank and the engine start and runup were all normal. With the pilot receiving instruction positioned in the front seat, she performed the initial takeoff from runway 16 and they remained in the traffic pattern with the intention of performing touch-and-go takeoff practice and landings. After making an uneventful three-point landing, the pilot receiving instruction applied full throttle and the airplane accelerated reaching an altitude of about 400 feet above ground level (agl). At that time, the engine abruptly stopped producing (total) power, although the propeller continued to rotate. The CFI opted to land on an access road. During the off-airport landing, the airplane sustained substantial damage to both wings and the fuselage when it collided with a tree before coming to rest in a vacant construction company storage area. The CFI stated that the airplane was too low for him to look at the instruments or perform troubleshooting steps and from the rear seat he did not have good visual access to the engine gauges. The pilot receiving instruction stated that immediately following the power loss, the CFI asked her what was happening. She confirmed that the throttle was fully forward, the mixture was rich, and the fuel selector valve and boost pump were both in the ON position. During a postaccident examination, investigators discovered the air induction box contained an approximate two by three feet piece of bunched up paper that was white and had a plastic type coating. The paper appeared to have mostly restricted the inlet cavity (see figure 1). Figure 1: Picture of Air Induction The lead mechanic who performed the annual inspection before the accident stated that as part of the annual inspection, the airplane needed a repair concerning a hole near the exhaust on the lower cowling. He hired a local repair person he normally uses to complete the fiberglass work and painting. After the maintenance, the airplane sat for a day with the lower cowling/ air filter off. After the work was completed andthe lower cowling was reinstalled, the mechanic completed a final inspection followed by a post-inspection run-up, with no discrepancies noted. The were no other anomalies found during the postaccident examination. ## Aircraft - Registration: [N36339](https://openairdocs.org/deregistered/N36339-2023-01-17), registration cancelled 2023-01-17, S/N 388-73, built 1973 (OpenAirDocs) - Reported make and model: BELLANCA 7KCAB - Registry model: [Bellanca 7KCAB](https://openairdocs.org/model/bellanca-7kcab) (registry code 1220701) (OpenAirDocs) - Registry engine: [Lycoming IO-320 series](https://openairdocs.org/engine/lycoming-io-320-series) (registry code 41509, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 388-73 - Year built: 1973 - Airframe hours: 5961 - Engines: Lycoming IO-320-E2A 150 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Boeing Employees Flying Assoc Inc - Registered owner: Boeing Employees Flying Assoc Inc - Airworthiness certificate: Standard, Normal; Standard, Aerobatic - Last inspection: Annual, June 11, 2020, 0 hours before - Departed: RNT, Renton, WA - Destination: RNT, Renton, WA - Airport: RNT, Renton Municipal Airport, runway 16, 5,382 × 200 ft, concrete - Equipment: ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 89; injuries: minor; flight instructor; airplane ratings: single-engine sea, multi-engine land; instrument ratings: airplane; medical: basicmed; last flight review May 29, 2020; seat: rear; restraint: none; flight hours: 7,387 total, 1,100 in this make and model, 7,320 as pilot in command, 38 in the last 90 days, 22 in the last 30 days, 2 in the last 24 hours - Student pilot; age 59; injuries: minor; private; airplane ratings: single-engine land; medical: basicmed; last flight review June 11, 2020; seat: front; restraint: 5-point; flight hours: 293 total, 46 in this make and model, 100 as pilot in command, 10 in the last 90 days, 8 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: 3,900 ft overcast - Temperature: 59 °F, dew point 48 °F - Altimeter: 29.98 inHg - Observed at: KMT ## 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 20200612019609A](https://openairdocs.org/incident/20200612019609A), Jun 12, 2020: Bellanca 7KCAB, Renton, WA, Substantial damage. During training on second go around, at approximately 400 feet, engine quit, prop wind milled, PIC attempted to land on road east of airport, left wing hit… ## Other investigations on N36339 (1) 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 SEA87LA046](https://openairdocs.org/ntsb/SEA87LA046), Jan 11, 1987: Bellanca 7KCAB (N36339), Bremerton, WA, substantial damage ## Docket (6 files) The files NTSB released with the investigation on April 20, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101432. 31.4 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 3.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13622638&FileExtension=pdf&FileName=Pilot%20Operator%20Accident%20Report%20Form%206120_Redacted-Rel.pdf - Pilot/operator aircraft accident report, NTSB form 6120.1 (pilot undergoing instruction) (item 2, PDF, 1 page, 23.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11775135&FileExtension=pdf&FileName=Z%20-%20Attachment%2001%20-%206120%20-%20PUI_Redacted-Rel.pdf - Records of conversation (item 3, PDF, 3 pages, 116 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11776194&FileExtension=pdf&FileName=Z%20-%20Attachment%2004%20-%20Record%20of%20Conversation-Rel.pdf - Airframe and engine examination (item 4, PDF, 6 pages, 3.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11776309&FileExtension=pdf&FileName=Z%20-%20Attachment%2003%20-%20Engine%20Examination%20Notes-Rel.pdf - Logbook excerpt (item 5, PDF, 1 page, 196 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11776319&FileExtension=pdf&FileName=Z%20-%20Attachment%2006%20-%20Logbook%20Excerpt-Rel.pdf - Response notes (item 6, PDF, 5 pages, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13646817&FileExtension=pdf&FileName=Z%20-%20Attachment%2005%20-%20Response-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.