# NTSB ERA17LA015: Cessna 150, N7948F, Stockbridge, GA, October 16, 2016 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: October 16, 2016, 14:30 local (18:30 UTC) - Place: Stockbridge, GA - Coordinates: 33.533054, -84.171943 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.5331&lon=-84.1719&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: Serious injuries - Injuries: 2 serious - Status: Completed, report April 13, 2020 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA FSDO, Continental Motors, Textron - NTSB case key (mKey): 94216 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA17LA015 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94216/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94216 - Page: https://openairdocs.org/ntsb/ERA17LA015 ## Probable cause A partial loss of engine power due to a stuck exhaust valve and the pilot's exceedance of the airplane’s critical angle of attack, which resulted in an aerodynamic stall. ## 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 · Damaged/degraded (probable cause); cases with it: [Cessna 150F, 3 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=2071814), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) - [Aircraft capability: climb capability](https://openairdocs.org/ntsb-findings/01061010): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Cessna 150F, 2 cases](https://openairdocs.org/ntsb-findings/01061010/cases.md?model=2071814), [All aircraft, 183 cases](https://openairdocs.org/ntsb-findings/01061010/cases.md) - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Cessna 150F, 4 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=2071814), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Cessna 150F, 9 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=2071814), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/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: [Cessna 150F, 8 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2071814), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Initial climb: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241); cases with it: [Cessna 150F, 6 cases](https://openairdocs.org/ntsb-events/241/sequence.md?model=2071814), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna 150F, 39 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2071814), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The private pilot completed an engine run-up before the personal flight with no anomalies noted. The pilot rotated the airplane about halfway down the runway. He stated that the airplane was not climbing normally during the takeoff, and a ground witness heard the engine making "popping" noises. The pilot attempted to clear trees off the end of the runway in order to make a controlled landing in the field on the other side, but the airplane impacted the field; the pilot was unable to recall any events that happened after passing over a tree. Examination of the wreckage revealed that the airplane displayed impact damage that included aftward crushing of the airplane's nose and the leading edges of both wings, which was consistent with an aerodynamic stall and impact with the ground in a nose-low attitude. Examination of the engine revealed the No. 4 cylinder's exhaust valve was stuck in the fully open position and coated in a carbon-like material. The stuck valve likely reduced engine power and airplane performance during the takeoff, which resulted in an aerodynamic stall. ## Factual narrative On October 16, 2016, about 1430 eastern daylight time, a Cessna 150 airplane, N7948F was substantially damaged when it impacted a field on takeoff from Berry Hill Airport (7GA7), Stockbridge, Georgia. The private pilot and the passenger sustained serious injuries. The airplane was privately owned and operated under the provisions of a Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed for the flight that was destined for Cherokee County Airport (CNI), Canton, Georgia. The pilot said he added 10 gallons of aviation fuel to each wing tank which brought each tank up to about 3/4 full. He then taxied to his backyard at the fly-in community to pick up his passenger, a bag of clothes, and a small dog. The pilot then taxied to runway 11 and conducted a runup of the engine. The runup was normal and the pilot departed in calm wind. About halfway down the 3,000-foot-long runway, the pilot rotated, and the airplane began to climb. The pilot soon observed that the airplane was not climbing normally, and he grew concerned that he would not clear the tree line about 500 ft off the departure end of the runway. The pilot steered the airplane toward the shortest tree and hoped to make a controlled landing in the field on the other side. He said that he remembered going over the tree, but nothing after that until he woke up in the hospital. A witness observed the airplane during takeoff and heard the engine making "popping" sounds as it climbed out. The pilot said he was wearing noise-cancelling headsets and did not hear anything abnormal with the engine during the quick flight. Post accident examination of the wreckage revealed that it came to rest about 800 ft off the departure end of the runway. The wreckage displayed aftward crushing of the airplane's nose, uniform aftward crush damage along most of the left wing's leading edge, and aftward crush damage to the outboard portion of the right wing. Examination of the engine revealed that each of the four cylinders exhibited dark deposits on the pistons and cylinder domes. When the engine was manually rotated, valve train continuity and compression were established on each cylinder except the No. 4 cylinder. The No. 4 cylinder was removed, and the exhaust valve was found stuck in the fully open position. The valve was manually removed from the cylinder with a hammer and a drift. The valve stem was dark and coated with a carbon-type material. The spark plugs were removed and examined. They exhibited normal wear when compared to the Champion Check-A-Plug chart, and dark deposits were observed in the electrode areas. The No. 4 bottom spark plug had oil and carbon type deposits in the electrode area.Both magnetos were removed from the engine and tested. When manually rotated, spark was produced at each terminal.The carburetor had separated from the engine and exhibited impact damage. The throttle control actuating arm and themixture control were connected and moved freely. The carburetor heat control was in the center position and would not move. There was no fuel screen installed. The floats were intact and attached to the needle valve. The needle valve seat was absent of debris.The oil screen was removed and a small about of carbon deposits were observed. A review of the airplane's maintenance logbooks revealed the last annual inspection was completed on May 10, 2016. At that time, the engine had accumulated 3,673.55 hours total time, with 604.85 hours since major overhaul. The pilot held a private pilot certificate with ratings for airplane single-engine land and instrument airplane. His last FAA third-class medical was issued on January 14, 2016. The pilot reported 276 total hours with 5 hours total time in the accident airplane make & model. The weather at Henry County Airport (HMP), Hampton, Georgia, about twelve miles southwest of the accident site, at 1435 was wind from 130° at 5 knots, visibility 10 miles, overcast at 9,000 ft, temperature 26° C, dewpoint 18° C, and an altimeter setting of 30.17 inches of mercury. The calculated density altitude was about as 2,100 ft. ## Aircraft - Registration: [N7948F](https://openairdocs.org/deregistered/N7948F-2017-03-07), registration cancelled 2017-03-07, S/N 15064048, built 1966 (OpenAirDocs) - Reported make and model: CESSNA 150 (F) - Registry model: [Cessna 150F](https://openairdocs.org/model/cessna-150f) (registry code 2071814) (OpenAirDocs) - Registry engine: [Continental 0-200 series](https://openairdocs.org/engine/continental-0-200-series) (registry code 17020, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 15064048 - Year built: 1966 - Engines: CONT MOTOR O-200 SERIES 100 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Utility - Last inspection: Annual, May 10, 2016, 20 hours before - Departed: 7GA7, Stockbridge, GA - Destination: CNI, Canton, GA - Airport: 7GA7, Berry Hill, runway 11, 3,000 × 40 ft, asphalt - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 45; injuries: serious; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, without waivers/limitations; last flight review March 14, 2016; seat: left; restraint: lap only; flight hours: 271 total, 5 in this make and model, 235 as pilot in command, 5 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: 9,000 ft overcast - Temperature: 79 °F, dew point 64 °F - Altimeter: 30.17 inHg - Observed at: HMP, 12 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 20161016016679A](https://openairdocs.org/incident/20161016016679A), Oct 16, 2016: Cessna 150F, Stockbridge, GA, Substantial damage. On October 16, 2016, about 1430 eastern daylight time, a Cessna 150F airplane, N7948F, impacted a field after takeoff from Berry Hill Airport (7GA7),… ## Docket (9 files) The files NTSB released with the investigation on November 18, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94216. 7.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 705 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478093&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Memorandum of Conversation - Pilot (item 2, .PDF, 26 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478094&FileExtension=.PDF&FileName=Memorandum%20of%20Conversation%20-%20Pilot-Master.PDF - Pilot Logbook Excerpt (item 3, .PDF, 698 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478095&FileExtension=.PDF&FileName=Pilot%20Logbook%20Excerpt-Master.PDF - Memorandum of Conversation - FAA (item 4, .PDF, 28 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478096&FileExtension=.PDF&FileName=Memorandum%20of%20Conversation%20-%20FAA-Master.PDF - Overhead View of Airport and Tree Line (item 5, .PDF, 169 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478097&FileExtension=.PDF&FileName=Overhead%20View%20of%20Airport%20and%20Tree%20Line-Master.PDF - Memorandum for Record - Weather (item 6, .PDF, 146 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478098&FileExtension=.PDF&FileName=Memorandum%20for%20Record%20-%20Weather-Master.PDF - Engine Manufacturer Examination and Inspection Report (item 7, .PDF, 3.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478099&FileExtension=.PDF&FileName=Engine%20Manufacturer%20Examination%20and%20Inspection%20Report-Master.PDF - Photographs of Accident Site and Damage (item 8, .PDF, 5 photos, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478100&FileExtension=.PDF&FileName=Photographs%20of%20Accident%20Site%20and%20Damage-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 9, .PDF, 567 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478101&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-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.