# NTSB ERA16LA065: Dehavilland Tiger Moth DH 82A, N9410, Modena, NY, December 12, 2015 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: December 12, 2015, 12:00 local (17:00 UTC) - Place: Modena, NY - Coordinates: 41.662776, -74.074447 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.6628&lon=-74.0744&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Eastern Region Aviation - Parties: FAA Albany FSDO - NTSB case key (mKey): 92435 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA16LA065 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/92435/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=92435 - Page: https://openairdocs.org/ntsb/ERA16LA065 ## Probable cause A partial loss of engine power due to a stuck No. 1 cylinder exhaust valve. ## 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 · Malfunction (probable cause); cases with it: [Dehavilland TIGER MOTH DH 82A, 2 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=2801002), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) - [Ignition system: magneto/distributor](https://openairdocs.org/ntsb-findings/01057414): Aircraft › Aircraft power plant · Damaged/degraded; cases with it: [Dehavilland TIGER MOTH DH 82A, 1 case](https://openairdocs.org/ntsb-findings/01057414/cases.md?model=2801002), [All aircraft, 101 cases](https://openairdocs.org/ntsb-findings/01057414/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 (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Dehavilland TIGER MOTH DH 82A, 3 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2801002), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Emergency descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Dehavilland TIGER MOTH DH 82A, 4 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2801002), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis During the initial climb after takeoff, the airplane experienced a partial loss of engine power. The pilot attempted to return to the runway; however, the airplane was not able to maintain altitude and struck trees about 1/4 mile from the airport. Postaccident examination of the engine revealed that the cylinder's exhaust valve was stuck open and that the No. 1 cylinder produced little to no compression when the crankshaft was rotated. The loss of compression on the No. 1 cylinder would have resulted in a partial loss of engine power and airplane's inability to maintain altitude. Disassembly of the left magneto revealed that its breaker spring was fractured, but investigators were unable to determine whether the left magneto failed before or during the accident. ## Factual narrative On December 12, 2015, about 1200 eastern standard time, a DeHavilland Tiger Moth DH-82A, N9410, was substantially damaged during a forced landing after takeoff from Old Orchard Airpark (2NK9), Modena, New York. The pilot and a passenger were not injured. Visual meteorological conditions prevailed and no flight plan had been filed for the personal flight that was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. The pilot reported that he conducted a pre-takeoff engine run, which included an operational check of the magnetos with no anomalies noted. The airplane subsequently experienced a 200-rpm reduction in engine power during the initial climb after takeoff from runway 18. The pilot attempted to return to the runway; however, the airplane was not able to maintain altitude and struck tress about 1/4-mile from the airport. The airplane was manufactured in 1940 and equipped with a DeHavilland Gipsy Major 1C, 145-horsepower engine Postaccident examination of the airplane by a Federal Aviation Administration inspector revealed that the airplane sustained substantial damage to both wings, the empennage, and the fuselage. When the inspector rotated the engine crankshaft, continuity was observed to the accessory section and compression was attained on all cylinders with exception of the forward (No. 1) cylinder, which produced "little to no compression." Due to the engine's disposition, the inspector was unable to check the ignition system for proper operation. No further examination of the engine was performed. The pilot further reported that subsequent teardown of the engine revealed that the No. 1 cylinder exhaust value was stuck in the open position. In addition, disassembly of the left magneto revealed that the "breaker spring" was fractured. The pilot stated that the loss of compression to one of the four engine cylinders alone would have resulted in a forced landing; however, he believed that the combination of the loss of compression on the No. 1 cylinder and the failure of the left magneto resulted in the loss of engine power that the airplane experienced during the accident flight. ## Aircraft - Registration: [N9410](https://openairdocs.org/aircraft/N9410), registered now, S/N DE-941, built 1940 (OpenAirDocs) - Reported make and model: DEHAVILLAND TIGER MOTH DH 82A - Registry model: [Dehavilland TIGER MOTH DH 82A](https://openairdocs.org/model/dehavilland-tiger-moth-dh-82a) (registry code 2801002) (OpenAirDocs) - Registry engine: [Dehav ENG GIPSY MAJOR](https://openairdocs.org/engine/dehav-eng-gipsy-major) (registry code 20004, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: DE-941 - Year built: 1940 - Airframe hours: 6260 - Engines: DEHAV ENG GIPSY MAJOR 145 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, October 15, 2019, 10 hours before - Departed: 2NK9, Modena, NY - Destination: 44N, LaGrangeville, NY - Airport: 2NK9, Old Orchard Airpark - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 66; injuries: none; commercial; airplane ratings: single-engine land; medical: class 2, with waivers/limitations; last flight review May 7, 2014; seat: front; flight hours: 2,300 total, 650 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 61 °F, dew point 41 °F - Altimeter: 30.11 inHg - Observed at: POU, 11 nm away ## 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 20151212022919A](https://openairdocs.org/incident/20151212022919A), Dec 12, 2015: Dehavilland TIGER MOTH DH 82A, Clintondale, NY, Substantial damage. On December 12, 2015 at approximately 11:50 am N9410 a Dehavilland tiger moth DH82A serial number DE-941 departed from old orchard air park(2NK9) in the town… ## Other investigations on N9410 (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 ERA13LA429](https://openairdocs.org/ntsb/ERA13LA429), Sep 22, 2013: De Havilland DH 82A (N9410), Rhinebeck, NY, substantial damage. Probable cause: The total loss of engine power for reasons that could not be determined because postaccident examinations revealed no anomalies that would have precluded normal operation, which resulted in a forced… ## Docket (3 files) The files NTSB released with the investigation on October 16, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=92435. 15.1 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 13.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11382985&FileExtension=pdf&FileName=1-16065%20PO%20Report_Redacted-Rel.pdf - Memorandums for record (FAA inspector and pilot) (item 2, PDF, 2 pages, 177 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11382753&FileExtension=pdf&FileName=2-Memos%20for%20Record-Rel.pdf - Investigation photographs (item 3, PDF, 2 pages, 2 photos, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11383059&FileExtension=pdf&FileName=4-Docket%20Photo%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.