# NTSB ERA20LA326: Stearman E75, N1524M, Honea Path, SC, September 21, 2020 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 3 · Limited · Final report - Date: September 21, 2020, 19:49 local (23:49 UTC) - Place: Honea Path, SC - Coordinates: 34.443611, -82.356389 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.4436&lon=-82.3564&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 102010 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA20LA326 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102010/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102010 - Page: https://openairdocs.org/ntsb/ERA20LA326 ## Probable cause The partial loss of engine power due to the fatigue failure of an engine cylinder and the pilot’s subsequent decision to overfly several suitable forced-landing sites while attempting to return to the departure airstrip. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Fatigue/wear/corrosion (probable cause); cases with it: [Boeing E75, 1 case](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=1380120), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Boeing E75, 1 case](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=1380120), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Boeing E75, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=1380120), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) ## Analysis The airplane departed and was in a continuous climb at 70 mph, at 2,500 rpm. The pilot observed a cylinder depart the engine and experienced a partial loss of engine power. A video of the event recorded the sound of the engine becoming quieter and the tachometer showed a continuous 1,000 rpm reading following the separation. The video captured the airplane maneuvering over open fields suitable for a forced landing as it descended back towards the departure airstrip. The recording ended before the airplane was destroyed by contact with trees and terrain 500 feet prior to the landing strip. Examination of the nine-cylinder radial engine revealed a separated cylinder, with all of its associated mounting studs fractured. Three of the mounting studs displayed features consistent with fatigue, likely due to inadequate torque applied at overhaul, which was completed less than 100 aircraft hours prior to the accident. ## Factual narrative On September 21, 2020, about 1949 eastern daylight time, a Stearman E75, N1524M, was destroyed when it was involved in an accident near Honea Path, South Carolina. The private pilot and his airline transport pilot-rated student were seriously injured. The flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. The pilot and his passenger were interviewed by Federal Aviation Administration (FAA) aviation safety inspectors. According to the pilot, he performed the takeoff from Ashley Field (SC01) and a few minutes into the flight he saw a “puff of smoke” and watched as a “jug” passed by the cockpit. He said the engine experienced a “50%” loss of engine power, which surprised him, and then he initiated a turn back to the departure airstrip. The passenger estimated the airplane was 1,000 ft- 1,100 ft altitude when he heard “a pop, then saw something went up in the air.” He added that he made a video recording of the flight and provided it to the FAA. Examination of the video revealed a shallow, continuous climb at 70 mph and 2,500 rpm. The sound of the engine was smooth and continuous when the recorder was held inside the open cockpit. As the passenger recorded the view outside the airplane, the wind noise overcame the soundtrack. The sound of the engine became quieter, the tachometer showed a continuous 1,000 rpm reading, and one of the occupants could be heard to say “…I heard that” as the airplane maneuvered over open fields as it descended. The recording ended before the airplane was destroyed by contact with trees and terrain 500 feet prior to the departure airstrip. Examination of photographs revealed a separated cylinder that was recovered and returned to the wreckage by an unknown person. The connecting rod was bent and remained attached to the crankshaft, but the piston was not recovered. All cylinder attachment/mounting studs were fractured. Photographs of the fracture surfaces examined at the NTSB Materials Laboratory revealed fractures consistent with fatigue on multiple studs. According to FAA aviation safety inspectors, the airplane’s tachometer displayed 919 aircraft hours. Excerpts of maintenance records revealed the airplane’s most recent annual inspection was completed on March 16, 2020, at 822.2 AC Hobbs time. On February 1, 2019, at 758.0 recording tach time, the nine-cylinder radial engine was overhauled. Prior to that, the engine was overhauled on March 12, 2016, at 669.9 recording tach time. Each overhaul, which occurred 88 hours apart, was performed by the same airframe and powerplant mechanic, who was deceased at the time of the accident. ## Aircraft - Registration: [N1524M](https://openairdocs.org/deregistered/N1524M-2021-10-02), registration cancelled 2021-10-02, S/N 75-8060, built 1943 (OpenAirDocs) - Reported make and model: Stearman E75 (Undesignat) - Registry model: [Boeing E75](https://openairdocs.org/model/boeing-e75) (registry code 1380120) (OpenAirDocs) - Registry engine: [Lycoming R680](https://openairdocs.org/engine/lycoming-r680) (registry code 41540, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 75-8060 - Year built: 1943 - Airframe hours: 919 - Engines: Lycoming R680-13 300 hp reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 16, 2020, 97 hours before - Destination: Same as departure - Airport: SC01, Ashley Fld, runway 13/31, 3,000 × 125 ft, grass/turf - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 64; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; seat: rear; restraint: 4-point; flight hours: 440 total, 200 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 60° at 5 knots - Visibility: 10 statute miles - Temperature: 61 °F, dew point 46 °F - Altimeter: 30.34 inHg - Observed at: KAND, 18 nm away - METAR: KAND 212356Z AUTO 06005KT 10SM CLR 16/08 A3034 RMK AO2 SLP270 T01610078 10217 20156 53002 ## 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 20200921017149A](https://openairdocs.org/incident/20200921017149A), Sep 21, 2020: Boeing E75, Hoena Path, SC, Destroyed. N51524M a Boeing E75 struck several trees and impacted the ground short of the airstrip at ashely field (SC01) in honea Path SC. The aircraft was destroyed,… ## Docket (7 files) The files NTSB released with the investigation on June 16, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102010. 64.4 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 memo for record (item 1, PDF, 1 page, 117 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12177663&FileExtension=pdf&FileName=Memorandum%20for%20Record%20NTSB%20Form%206120.1-Rel.pdf - FAA interview summaries (item 2, PDF, 3 pages, 367 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12176802&FileExtension=pdf&FileName=FAA%20Interview%20Summaries_Redacted-Rel.pdf - Witness statements (item 3, PDF, 5 pages, 16.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12177577&FileExtension=pdf&FileName=Witness%20statments_Redacted-Rel.pdf - Video file (item 4, MP4, 9.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12176715&FileExtension=mp4&FileName=20200921_191513_003-Rel.mp4 - Materials laboratory (item 5, PDF, 4 pages, 21.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12177587&FileExtension=pdf&FileName=ERA20LA326%20Fractured%20Head%20Stud%20Evaluation_Redacted-Rel.pdf - Maintenance records (item 6, PDF, 3 pages, 14.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12177787&FileExtension=pdf&FileName=Maintenance%20Record%20Exerpts_Redacted-Rel.pdf - Photo array (item 7, PDF, 5 pages, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14030799&FileExtension=pdf&FileName=Photo%20Array-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.