# NTSB ERA22LA380: Cessna 150, N8797G, Berry, AL, August 20, 2022 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: August 20, 2022, 11:40 local (16:40 UTC) - Place: Berry, AL - Coordinates: 33.5172, -87.4558 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.5172&lon=-87.4558&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) - 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 FSDO - NTSB case key (mKey): 105779 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA22LA380 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105779/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=105779 - Page: https://openairdocs.org/ntsb/ERA22LA380 ## Probable cause A partial loss of engine power due to the No. 3 cylinder’s 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 · Malfunction (probable cause); cases with it: [Cessna 150, 1 case](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=2071802), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Cessna 150, 1 case](https://openairdocs.org/ntsb-events/340/sequence.md?model=2071802), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Enroute-cruise: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342); cases with it: [Cessna 150, 2 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2071802), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Cessna 150, 4 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2071802), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The student pilot and flight instructor reported that the engine lost partial power during cruise flight. The instructor assumed control of the airplane, attempted to restore power, and performed a forced landing to a cleared area of wooded terrain, resulting in substantial damage to the airplane. The postaccident examination of the engine revealed that the exhaust valve in the No. 3 cylinder was stuck in the open position. Based on this finding, it is likely that the partial loss of engine power was the result of the No. 3 cylinder’s stuck exhaust valve. The engine maintenance records were not available for review, and the maintenance history of the engine could not be determined. ## Factual narrative On August 20, 2022, about 1140 central daylight time, a Cessna 150F, N8797G, was substantially damaged when it was involved in an accident near Berry, Alabama. The flight instructor and the student pilot were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. According to the student pilot, he had the airplane configured in cruise flight when the engine lost partial power. He said, “it felt like one cylinder had quit. It didn’t vibrate like we’d broken a [connecting] rod; it was more like we lost a valve.” The instructor stated that after the partial loss of power, he assumed control of the airplane, adjusted to best glide airspeed, performed remedial actions to restore power, and searched for a suitable forced landing site during the descent. He said he prepared for a landing in trees when, at low altitude, he saw a “cutover” in the trees that had been cleared by local loggers. The instructor maneuvered the airplane into the clearing where it collided with terrain and cut trees, substantially damaging the engine compartment, cabin, and both wings. The airplane came to rest upright in rough terrain and cut timber. It rested nose-down on the propeller and the right wing tip. The terrain and the airplane’s resting place precluded on-site examination, and the airplane was recovered from the site to a secure facility for the examination. Before the engine examination could be completed, and before the wreckage was released, the insurance carrier for the airplane sold the wreckage. The buyer, unaware that the airplane had been retained as evidence, began disassembling the airplane for the sale of its parts. Before the airplane was located and arrangements could be made for an engine examination, the airplane’s buyer had partially disassembled the engine. A Federal Aviation Administration inspector examined the partially disassembled engine. The engine was rotated by hand at the propeller flange and was found “smooth with no issues.” Compression could not be confirmed due to removal of the upper cylinder spark plugs, cylinder covers, push rods, and rocker assemblies. It could not be determined from which cylinder the spark plugs, push rods, and rocker arms had been removed. Four spark plugs were described as “oily, [with] carbon buildup, corroded and contaminated.” The left magneto was too damaged and disassembled to get it to spark. Sufficient rotation could not be applied to achieve spark on the right magneto. The carburetor was sheared off of the intake manifold. The No. 1 cylinder was cracked at the rocker box. According to the inspector, the crack extended the full length across the mounting pin section, with the bushings found loose due to the expansion from the crack. Photographs were examined by the manager of product field performance for the engine manufacturer, who stated that the exhaust valve in the No. 3 cylinder was stuck in the open position. With the rockers removed, bothvalves should be pressed closed by valve spring tension. The exhaust valve stuck in the open position would result in a substantial power loss. Further, he stated that bushings were not installed in the rocker boxes of the cylinders at the factory. The bushings pictured in the No. 1 cylinder rocker box reflected a repair that had been performed on the cylinder at some time in its service life. According to the manager, the loose bushing would affect the dry lifter clearance and adversely affect valve performance. The engine maintenance records were not available for review, and the maintenance history of the engine could not be determined. ## Aircraft - Registration: [N8797G](https://openairdocs.org/aircraft/N8797G), registered now, S/N 15062897, built 1966 (OpenAirDocs) - Reported make and model: CESSNA 150 (F) - Registry model: [Cessna 150](https://openairdocs.org/model/cessna-150) (registry code 2071802) (OpenAirDocs) - Registry engine: [Continental 0-200 series](https://openairdocs.org/engine/continental-0-200-series) (registry code 17020, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 15062897 - Year built: 1966 - Airframe hours: 3059 - Engines: Continental O-200 100 hp reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 29, 2022 - Departed: DCU, Decatur, AL - Destination: TCL, Tuscaloosa, AL - Equipment: Electronic primary flight display, Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 39; injuries: minor; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; seat: right; restraint: lap only; flight hours: 1,835 total, 438 in this make and model, 1,738 as pilot in command, 379 in the last 90 days, 115 in the last 30 days, 13 in the last 24 hours - Student pilot; student; medical: class 3; seat: left; flight hours: 20 total, 17 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: 1,700 ft broken - Temperature: 81 °F, dew point 75 °F - Altimeter: 30.13 inHg - Observed at: KTCL, 20 nm away - METAR: KTCL 201520Z 22005KT 10SM SCT012 BKN017 OVC023 27/24 A3013 RMK AO2 T02670239 $ ## 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 20220820014839A](https://openairdocs.org/incident/20220820014839A), Aug 20, 2022: Cessna 150, Berry, AL, Destroyed. Instructor pilot with student on a cross country flight when the aircraft lost power and was forced to make an emergency landing near a logging road. The… ## Docket (4 files) The files NTSB released with the investigation on December 20, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=105779. 10.0 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 10 pages, 7.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16303121&FileExtension=pdf&FileName=NTSB%20Form%206120_Redacted-Rel.pdf - Memorandum for record a�� telephone interview, student pilot (item 2, PDF, 1 page, 116 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16305513&FileExtension=pdf&FileName=Record%20of%20Conversation%20Sanders%20Watson-Rel.pdf - Engine exam memorandum for record (item 3, PDF, 5 pages, 917 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16307290&FileExtension=pdf&FileName=Memorandum%20For%20Record%20Engine%20Exam%20FAA-Rel.pdf - Photo array (item 4, PDF, 3 pages, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16303674&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.