# NTSB CEN17LA093: Piper J3C, N7039H, Brenham, TX, January 30, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: January 30, 2017, 15:48 local (21:48 UTC) - Place: Brenham, TX - Coordinates: 30.219722, -96.374443 - Nearby events: https://openairdocs.org/map.md?lat=30.2197&lon=-96.3744&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 September 6, 2017 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA Houston FSDO - NTSB case key (mKey): 94671 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN17LA093 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94671/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94671 - Page: https://openairdocs.org/ntsb/CEN17LA093 ## Probable cause The reciprocating engine's exhaust valve being stuck in the “open” position, which resulted in a partial loss of engine power during initial climb. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip engine power section](https://openairdocs.org/ntsb-findings/01058520): Aircraft › Aircraft power plant · Not specified (probable cause); cases with it: [Piper/Dear J3C, 1 case](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=710051C), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md) - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Piper/Dear J3C, 1 case](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=710051C), [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/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: [Piper/Dear J3C, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=710051C), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Piper/Dear J3C, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=710051C), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The student pilot and flight instructor were conducting a personal flight. The flight instructor reported that the pretakeoff checks were "normal" but that, during the takeoff, the engine felt "weak" and that the engine lost power during the initial climb. The flight instructor conducted a forced landing to a field, during which the airplane impacted the top of a tree and then the ground. Examination of the airplane revealed that the exhaust valve for the No. 4 cylinder was stuck in the "open" position possibly due to excessive deposits from the combustion process. It is likely that the stuck exhaust valve resulted in the partial loss of engine power reported by the flight instructor. ## Factual narrative On January 30, 2017, about 1538 central standard time, a Piper J3C airplane, N7039H, sustained substantial damage during a forced landing following a partial loss of engine power during initial climb after takeoff near Brenham, Texas. The student pilot and flight instructor were not injured. The airplane's fuselage and wings were damaged during the forced landing. The aircraft was registered to and operated by the student pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which was not on a flight plan. The flight was originating at the time of the accident for an unconfirmed destination. The flight instructor reported that pre-takeoff engine checks were normal. He noted that during the takeoff he and the student pilot noticed that the engine felt "weak" but thought it was due to being unaccustomed to the airplane. The flight instructor said that he verified that the magneto switch was in the both position , the primer was locked, and the carburetor heat was off. By this time the remaining usable runway had been exhausted and the airplane was sinking with full throttle applied. He selected a field in which to execute a landing but the airplane impacted the top of a tree and then the ground during the forced landing. Examination of the airplane by a Federal Aviation Administration Inspector revealed that the exhaust valve for the No. 4 cylinder was stuck in the open position due to excessive deposits from the combustion process. ## Aircraft - Registration: [N7039H](https://openairdocs.org/deregistered/N7039H-2019-04-09), registration cancelled 2019-04-09, S/N 4601 (OpenAirDocs) - Reported make and model: PIPER J3C - Registry model: [Piper/Dear J3C](https://openairdocs.org/model/piper-dear-j3c) (registry code 710051C) (OpenAirDocs) - Registry engine: [Continental A&C65 series](https://openairdocs.org/engine/continental-a-c65-series) (registry code 17003, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 4601 - Airframe hours: 6749 - Engines: CONT MOTOR A75-8F(C)8 75 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 4, 2016, 27 hours before - Departed: 11R, BRENHAM, TX - Destination: Waco, TX - Airport: 11R, Brenham Muni, runway 16, 6,003 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 36; injuries: none; commercial; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: class 3, without waivers/limitations; seat: rear; restraint: 3-point - Student pilot; age 41; injuries: none; student; medical: class 3, without waivers/limitations; seat: front; restraint: 3-point ## Weather - Conditions: Visual (VMC), Day - Wind: 240° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 77 °F, dew point 25 °F - Altimeter: 30.18 inHg - Observed at: 11R ## 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 20170130000629A](https://openairdocs.org/incident/20170130000629A), Jan 30, 2017: Piper/Dear J3C, Brenham, TX, Substantial damage. The aircraft was departing from Brenham Municipal Airport (11R) using runway 16. Shortly after take off, it lost power and could not maintain altitude. The… ## Docket (4 files) The files NTSB released with the investigation on June 15, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94671. 4.7 MB in all. - Flight Instructor's Statement (item 1, .PDF, 273 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40453278&FileExtension=.PDF&FileName=Flight%20Instructor%27s%20Statement-Master.PDF - Photographs provided by FAA (item 2, .PDF, 8 photos, 3.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40453279&FileExtension=.PDF&FileName=Photographs%20provided%20by%20FAA-Master.PDF - Maintenance Record Excerpts (item 3, .PDF, 761 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40453280&FileExtension=.PDF&FileName=Maintenance%20Record%20Excerpts-Master.PDF - Record of Conversation with FAA Inspector (item 4, .PDF, 54 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40453281&FileExtension=.PDF&FileName=Record%20of%20Conversation%20with%20FAA%20Inspector-Master.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.