# NTSB WPR10LA424: Grumman American Avn. AA-5A, N26118, Lakeview, OR, August 22, 2010 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 22, 2010, 11:50 local (18:50 UTC) - Place: Lakeview, OR - Coordinates: 42.161109, -120.398887 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.1611&lon=-120.3989&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 December 20, 2010 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: FAA FSDO - NTSB case key (mKey): 77054 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR10LA424 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/77054/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=77054 - Page: https://openairdocs.org/ntsb/WPR10LA424 ## Probable cause A partial loss of engine power during the initial climb due to a stuck 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 · Failure (probable cause); cases with it: [Grumman American Avn. AA-5A, 1 case](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=3960106), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined; cases with it: [Grumman American Avn. AA-5A, 4 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=3960106), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/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: [Grumman American Avn. AA-5A, 4 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=3960106), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Initial climb: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Grumman American Avn. AA-5A, 6 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=3960106), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The pilot reported that the preflight run-up was uneventful. Shortly after takeoff, at approximately 150 feet above ground level, the engine suddenly dropped rpm; the pilot verified fuel quantity, and attempted to lean the engine. Despite the pilot’s efforts, the problem persisted, and he initiated a forced landing into a nearby field. During the landing roll, the airplane’s left wing struck a fence post, and its empennage collided with high sage brush. Examination of the engine by a certificated airframe and powerplant (A&P) mechanic revealed low compression within the number three cylinder. Further examination revealed that the exhaust valve was stuck in the full open position. The examination revealed no further anomalies with the cylinder assembly or engine. ## Factual narrative On August 22, 2010, about 1150 Pacific daylight time, a Grumman AA-5A airplane, N26118, sustained substantial damage during a forced landing, about 1 mile north of the Lake County Airport, Lakeview, Oregon (LKV). The private pilot and passenger were not injured. The airplane was operated by the pilot as a personal cross-country flight under the provisions of 14 Code of Federal Regulations (CFR) Part 91, when the accident occurred. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated at Lakeview, and was en route to Burns, Oregon. The pilot reported that during the preflight and preflight run-up he did not detect any anomalies with the airplane’s engine. Shortly after takeoff, at approximately 150 feet above ground level (agl), the engine revolutions per minute (rpm) dropped from 2,500 to 1,500 rpm. The pilot immediately checked fuel quantities, and attempted to lean the engine. Despite the pilot’s efforts, the problem persisted, and the pilot initiated an off-airport landing to an open field about 1 mile north of LKV. The pilot stated that during the landing roll, the airplane’s left wing struck a fence post and the empennage collided with tall sage brush, both of which resulted in substantial damage to the airplane. Postaccident examination of the airplane by a certificated airframe and powerplant (A&P) mechanic revealed that the airplane’s left wing and empennage sustained substantial damage. When an engine compression test was conducted, no compression was found in the number three cylinder. Further examination revealed that the exhaust valve was stuck in the full open position. The examination revealed no further anomalies with the cylinder assembly or engine. ## Aircraft - Registration: [N26118](https://openairdocs.org/deregistered/N26118-2018-01-12), registration cancelled 2018-01-12, S/N AA5A0440, built 1977 (OpenAirDocs) - Reported make and model: GRUMMAN AMERICAN AVN. CORP. AA-5A - Registry model: [Grumman American Avn. AA-5A](https://openairdocs.org/model/grumman-american-avn-aa-5a) (registry code 3960106) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: AA5A0440 - Engines: LYCOMING O-320 SERIES 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Nicholls Tony - Registered owner: Nicholls Tony - Airworthiness certificate: Standard, Normal - Last inspection: Annual, January 1, 2010 - Departed: KLKV, Lakeview, OR - Destination: KBNO, Burns, OR - Flight plan: Unknown - Airport: KLKV, Lake County Airport, runway 34, 5,306 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 46; injuries: none; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; seat: left; flight hours: 500 total, 400 in this make and model, 500 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 160° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 59 °F, dew point 37 °F - Altimeter: 30.18 inHg - Observed at: KLKV, 1 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 20100822042789A](https://openairdocs.org/incident/20100822042789A), Aug 22, 2010: Grumman Ame AA-5A, Lakeview, OR, Substantial damage. Pilot stated the airplane lost engine power after departure at 200 feet AGL. Pilot continued straight ahead and landed one mile northwest of the airport. Pilot… ## Docket (1 files) The files NTSB released with the investigation on October 29, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=77054. 254 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 254 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40337430&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.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.