# NTSB CEN10LA171: Loehr Thomas H Zenith Stol CH701, N144AC, Eldon, MO, March 22, 2010 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 22, 2010, 18:54 local (23:54 UTC) - Place: Eldon, MO - Coordinates: 38.360553, -92.571388 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.3606&lon=-92.5714&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report August 12, 2010 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 75570 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN10LA171 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/75570/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=75570 - Page: https://openairdocs.org/ntsb/CEN10LA171 ## Probable cause A loss of engine thrust during takeoff due to the failure of the engine-to-propeller drive belts as a result of improper belt tension. Contributing to the accident was the non-certificated pilot's improper preflight inspection. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Propeller system](https://openairdocs.org/ntsb-findings/01046100): Aircraft › Aircraft propeller/rotor · Failure (probable cause); cases with it: [Loehr Thomas H ZENITH STOL CH701, 1 case](https://openairdocs.org/ntsb-findings/01046100/cases.md?model=056211K), [All aircraft, 20 cases](https://openairdocs.org/ntsb-findings/01046100/cases.md) - [Propeller system](https://openairdocs.org/ntsb-findings/01046100): Aircraft › Aircraft propeller/rotor · Not serviced/maintained (probable cause); cases with it: [Loehr Thomas H ZENITH STOL CH701, 1 case](https://openairdocs.org/ntsb-findings/01046100/cases.md?model=056211K), [All aircraft, 20 cases](https://openairdocs.org/ntsb-findings/01046100/cases.md) - [Inspection: preflight inspection](https://openairdocs.org/ntsb-findings/02061510): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Loehr Thomas H ZENITH STOL CH701, 1 case](https://openairdocs.org/ntsb-findings/02061510/cases.md?model=056211K), [All aircraft, 551 cases](https://openairdocs.org/ntsb-findings/02061510/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Aircraft maintenance event](https://openairdocs.org/ntsb-events/040); cases with it: [Loehr Thomas H ZENITH STOL CH701, 1 case](https://openairdocs.org/ntsb-events/040/sequence.md?model=056211K), [All aircraft, 484 cases](https://openairdocs.org/ntsb-events/040/sequence.md) - [Initial climb: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Loehr Thomas H ZENITH STOL CH701, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=056211K), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Loehr Thomas H ZENITH STOL CH701, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=056211K), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis Shortly after takeoff, at 300 feet above ground level, the engine "revved excessively and power was lost to the propeller." The pilot performed an off airport forced landing. During the forced landing, the airplane impacted terrain and sustained substantial damage to the forward fuselage. Examination of the airplane revealed that both engine-to-propeller drive belts failed, which led to the reported engine overspeed and lack of propeller drive. A representative of the manufacturer stated that the belt failure during the accident was caused by loose belts or a lack of proper tension on the belts and that the belt tension should have been checked during a preflight inspection. ## Factual narrative On March 22, 2010, at 1854 central daylight time, a Loehr Zenith STOL CH701 experimental airplane, N144AC, sustained substantial damage during takeoff from the Eldon Model Airpark (H79), Eldon, Missouri. The non-certificated pilot, who was the sole occupant and registered owner, was not injured. Visual meteorological conditions prevailed, and a flight plan was not filed for the Title 14 Code of Federal Regulations Part 91 personal flight. The local flight was originating at the time of the accident. According to the pilot, shortly after takeoff at 300 feet above ground level (agl), the engine "revved excessively and power was lost to the propeller." The pilot performed an off airport forced landing. During the forced landing, the airplane impacted terrain and sustained substantial damage to the forward fuselage. Examination of the airplane by a Federal Aviation Administration inspector revealed that both engine to propeller drive belts failed which led to the reported engine overspeed and lack of propeller drive. The belts displayed missing drive lugs. The nut which retained the propeller pulley was found loose. The pilot reported the airplane underwent its most recent conditional inspection on September 30, 2009. The airplane had accumulated 122 total hours. According to the manufacturer of the engine to propeller drive system, Valley Engineering, L.L.C., the pilot had flown the airplane to their facility a couple months prior to the accident. Their inspection of the airplane revealed the drive belts were out of adjustment and needed servicing. During a telephone conversation between the NTSB investigator-in-charge and the manufacturer, the manufacturer reported that the belt failure during the accident was caused by loose belts or a lack of proper tension on the belts. The representative stated that belt tension should have been checked during a preflight inspection. On the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1), Recommendation section, the pilot reported, "A more thorough look at belts from temperature change of extreme cold to warm." ## Aircraft - Registration: [N144AC](https://openairdocs.org/aircraft/N144AC), registered now, S/N 74461, built 2006 (OpenAirDocs) - Reported make and model: LOEHR THOMAS H ZENITH STOL CH701 - Registry model: [Loehr Thomas H ZENITH STOL CH701](https://openairdocs.org/model/loehr-thomas-h-zenith-stol-ch701) (registry code 056211K) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 74461 - Airframe hours: 122 - Engines: Volkswagon 80 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Wendt Dan L - Registered owner: Wendt Dan L - Airworthiness certificate: Special, Experimental light sport (Special) - Last inspection: Condition, September 30, 2009 - Departed: H79, Eldon, MO - Destination: H79, Eldon, MO ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 57; injuries: none; seat: left; flight hours: 47 total, 47 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 61 °F ## 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 20100322030589A](https://openairdocs.org/incident/20100322030589A), Mar 22, 2010: Loehr Thoma ZENITH STOL, Eldon, MO, Substantial damage. The pilot stated he taxied to runway 36, checked engine operation, began take-off, and climbed to around 300 feet AGL. He stated the engine then revved with… ## Docket (9 files) The files NTSB released with the investigation on May 26, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=75570. 5.6 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 360 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329802&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Record of Conversation (item 2, .PDF, 12 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329803&FileExtension=.PDF&FileName=Record%20of%20Conversation-Master.PDF - FAA Statement (item 3, .PDF, 62 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329805&FileExtension=.PDF&FileName=FAA%20Statement-Redacted.PDF - Logbook Entry (item 4, .PDF, 422 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329806&FileExtension=.PDF&FileName=Logbook%20Entry-Redacted.PDF - Photo 01 View of Drive System (FAA) (item 5, .PDF, 952 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329807&FileExtension=.PDF&FileName=Photo%2001%20View%20of%20Drive%20System%20(FAA)-Master.PDF - Photo 02 View of Drive System (FAA) (item 6, .PDF, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329808&FileExtension=.PDF&FileName=Photo%2002%20View%20of%20Drive%20System%20(FAA)-Master.PDF - Photo 03 View of Drive Belt (FAA) (item 7, .PDF, 590 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329809&FileExtension=.PDF&FileName=Photo%2003%20View%20of%20Drive%20Belt%20(FAA)-Master.PDF - Photo 04 View of Drive Belt (FAA) (item 8, .PDF, 729 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329811&FileExtension=.PDF&FileName=Photo%2004%20View%20of%20Drive%20Belt%20(FAA)-Master.PDF - Photo 05 View of Drive Belts (FAA) (item 9, .PDF, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329812&FileExtension=.PDF&FileName=Photo%2005%20View%20of%20Drive%20Belts%20(FAA)-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.