# NTSB CEN22LA106: Dehavilland Tiger Moth DH 82A, N5300, Lampasas, TX, January 23, 2022 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: January 23, 2022, 17:28 local (23:28 UTC) - Place: Lampasas, TX - Coordinates: 31.072856, -98.233153 - Nearby events: https://openairdocs.org/map.md?lat=31.0729&lon=-98.2332&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA - SAT FSDO - NTSB case key (mKey): 104548 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN22LA106 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/104548/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=104548 - Page: https://openairdocs.org/ntsb/CEN22LA106 ## Probable cause The failure of a bolt in the engine valve system which resulted in malfunction of the engine exhaust valve system and a partial loss of engine power. The rough terrain encountered during the forced landing contributed to the outcome. ## 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 · Failure (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) - [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) - [Runway/land/takeoff/taxi surface](https://openairdocs.org/ntsb-findings/03023000): Environmental issues › Physical environment · Effect on operation; cases with it: [Dehavilland TIGER MOTH DH 82A, 1 case](https://openairdocs.org/ntsb-findings/03023000/cases.md?model=2801002), [All aircraft, 253 cases](https://openairdocs.org/ntsb-findings/03023000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: 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) ## Analysis The airplane’s engine lost partial power and the pilot was unable to maintain altitude. He executed a forced landing to a terraced farm field. During the landing, the airplane struck one of the terraced areas and nosed over. The airplane sustained substantial damage to the rudder, engine mounts, and lower right wing. Postaccident examination of the engine revealed that the ball end of the No. 2 cylinder exhaust valve rocker was not seated in the pushrod. Additionally, the head of one of the bolts securing the rocker arm bracket had fractured and the bolt head was found in the rocker cover. Based on the available evidence it is likely that the fractured bolt head allowed enough movement of the No. 2 cylinder rocker arm bracket for the pushrod to become separated from the ball end of the rocker arm. This prevented the exhaust valve for the No.2 cylinder from opening and thereby reducing the power output of the engine. ## Factual narrative On January 23, 2022, about 1728 central standard time, a de Havilland Tiger Moth DH-82A, N5300, was substantially damaged when it was involved in an accident near Lampasas, Texas. The pilot and passenger received minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that about 20 minutes into the pleasure flight the engine began to run rough, and he immediately turned the airplane back toward the departure airport, checked that the fuel was on, mixture was rich, and the throttle was open. The engine continued to lose power and he decided to divert to a different private airport. The engine was producing partial power but not enough to maintain altitude. As the airplane approached the private airport, the pilot perceived that the airplane was too high, and he turned the airplane. During the turn he realized that he had misjudged the height and decided that completing the turn was not a good idea, leveled the wings, and committed to going straight ahead. The area where the airplane landed was terraced and as it touched down the airplane hit one of the terraced areas, skipped, nosed over, and came to rest inverted. The airplane sustained substantial damage to the rudder, engine mounts, and lower right wing. After the accident, the pilot, who is also a mechanic, performed an examination of the airplane and engine. The engine was able to rotate, and compression was confirmed on all cylinders. While examining the valve system for the No. 2 cylinder he found that the ball end of the exhaust valve rocker arm was not seated in the end of the pushrod. He also found that one of the bolts securing the rocker arm assembly had the bolt head separated from its shank. The missing bolt head was in the rocker cover. ## Aircraft - Registration: [N5300](https://openairdocs.org/aircraft/N5300), registered now, S/N T-5703, 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: T-5703 - Year built: 1940 - Engines: De Havilland Gipsy Major 1C 140 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 16, 2021 - Departed: LZZ, Lampasas, TX ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; injuries: minor; commercial; airplane ratings: single-engine land; instrument ratings: helicopter, airplane; medical: class 2, with waivers/limitations; seat: rear; restraint: 4-point; flight hours: 4,850 total, 2 in this make and model, 3,830 as pilot in command, 22 in the last 90 days, 5 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: 4,400 ft broken - Temperature: 55 °F, dew point 34 °F - Altimeter: 30.09 inHg - Observed at: KLZZ, 3 nm away - METAR: METAR KLZZ 232335Z AUTO 21004KT 10SM BKN044 OVC055 13/01 A3009 RMK AO2 T01310013= ## 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 20220123001879A](https://openairdocs.org/incident/20220123001879A), Jan 23, 2022: Dehavilland TIGER MOTH DH 82A, Lampasas, TX, Substantial damage. N5300 a 1940 de havilland tiger moth dh 82A bi-plane aircraft flipped over during an off-airport landing after suffering partial power loss in flight. The… ## Docket (4 files) The files NTSB released with the investigation on June 14, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=104548. 4.1 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14594497&FileExtension=pdf&FileName=6120.1%2023Jan22_Redacted-Rel.pdf - Pilot statement (item 2, PDF, 1 page, 102 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14594863&FileExtension=pdf&FileName=Statement%20for%20the%20FAA_Redacted-Rel.pdf - Aircraft examination by owner (item 3, PDF, 4 pages, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14594402&FileExtension=pdf&FileName=Gipsy%20Major%20Inspection-Rel.pdf - Photographs (item 4, PDF, 2 pages, 944 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14595833&FileExtension=pdf&FileName=Docket%20Photo%20array%20template-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.