# NTSB CEN20LA005: Zenair Zenith CH 701, N701BJ, Garden Ridge, TX, October 5, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 5, 2019, 10:30 local (15:30 UTC) - Place: Garden Ridge, TX - Coordinates: 29.621944, -98.277221 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=29.6219&lon=-98.2772&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 June 3, 2020 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA - NTSB case key (mKey): 100399 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN20LA005 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100399/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100399 - Page: https://openairdocs.org/ntsb/CEN20LA005 ## Probable cause The partial loss of engine power for reasons that could not be determined based on the available evidence. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Johnson-Graber ZENITH CH-701, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=05614EO), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) - [Terrain: rough terrain](https://openairdocs.org/ntsb-findings/03021015): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Johnson-Graber ZENITH CH-701, 1 case](https://openairdocs.org/ntsb-findings/03021015/cases.md?model=05614EO), [All aircraft, 442 cases](https://openairdocs.org/ntsb-findings/03021015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Unknown or undetermined](https://openairdocs.org/ntsb-events/000); cases with it: [Johnson-Graber ZENITH CH-701, 1 case](https://openairdocs.org/ntsb-events/000/sequence.md?model=05614EO), [All aircraft, 1,703 cases](https://openairdocs.org/ntsb-events/000/sequence.md) - [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Johnson-Graber ZENITH CH-701, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=05614EO), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) ## Analysis The pilot reported that the airplane was fully loaded with fuel and that all preflight checks were normal for the personal flight. He indicated that, after departure, as the airplane reached between about 10 and 15 ft above ground level, the engine power rolled back "opposite of a surge." He landed straight ahead into brush past the runway end. During the landing, the right main landing gear and nose landing gear collapsed, and the fuselage sustained substantial damage. During the engine examination, several items were identified that could have contributed to a reduction or loss of engine power, including a lack of a fuel return line, a loose exhaust pipe, dirty air filters, and a disconnected choke lever. However, an engine test run was conducted without correcting any of the identified deficiencies, and the engine performed without interruption; no anomalies were noted. Further, no anomalies were noted during the airframe examination. Although the conditions were conducive to serious carburetor icing at glide power, the airplane was operating at takeoff power at the time of the accident. The reason for the loss of engine power could not be determined. ## Factual narrative ***This report was modified on April 17, 2020. Please see the docket for this accident to view the original report.*** On October 5, 2019, about 1030 central daylight time, a Zenair Zenith CH-701 airplane, N701BJ, impacted terrain near Garden Ridge, Texas, following a partial loss of engine power after takeoff. The private pilot and passenger were not injured. The airplane was substantially damaged. The airplane was registered to the pilot and operated as a Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed, and the flight which was operating without a flight plan. The flight was originating from Kitty Hawk Flying Field Ultralight Flightpark (TS67), Garden Ridge, Texas, when the accident occurred. The pilot reported the airplane was fully loaded with fuel, it started normally, and all preflight checks were normal. The airplane reached 10-15 ft above the ground during takeoff when the engine RPM rolled back "opposite of a surge." The pilot pulled the throttle control back to idle and landed straight ahead in an area of brush off the end of the runway. The right main gear and nose gear collapsed, and the fuselage exhibited buckling. An examination of the engine and airframe was conducted by a representative of Rotech and a Federal Aviation Administration inspector. No anomalies were found during the airframe examination. When first examined, the engine was attached to the engine mount and firewall of the airplane, and the engine cowling was still in place. The retaining nut for the 2/4 cylinder carburetor choke lever was not present and the choke lever was found detached at the control valve. The fuel feed line to the mechanical fuel pump was badly cracked. The carburetor float bowls were removed and inspected. Some debris was found in the 2/4 carburetor; however, the main jet was clear of any obstructions. Examination also found there was no fuel return line installed in the airplane as recommended by the engine manufacturer, the No. 3 cylinder exhaust pipe was loose, and the air filters were dirty. The damaged propeller was removed from the engine and a new propeller was installed for test run purposes. No other repairs were made to the engine. The engine was turned over with the use of the engine's electric starter. After a few rotations the engine started and ran at idle. The throttle was then advanced to around 3,500 rpm and then to 4,000 RPM. All engine parameters appeared normal after several minutes and the engine was shut down. No anomalies were noted during the engine test run. The pilot reported at the time of the accident the temperature was 80° F and the dewpoint was 72° F. A review of the Federal Aviation Administration's carburetor icing probability chart indicated that weather conditions at the time of the accident were conducive to serious carburetor icing at glide power. ## Aircraft - Registration: [N701BJ](https://openairdocs.org/aircraft/N701BJ), registered now, S/N JN316, built 2002 (OpenAirDocs) - Reported make and model: Zenair ZENITH CH 701 (No Series) - Registry model: [Johnson-Graber ZENITH CH-701](https://openairdocs.org/model/johnson-graber-zenith-ch-701) (registry code 05614EO) (OpenAirDocs) - Registry engine: [Bombardier ROTAX (ALL)](https://openairdocs.org/engine/bombardier-rotax-all) (registry code 09050, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: JN316 - Year built: 2002 - Airframe hours: 349.2 - Engines: Rotax 912 UL-S 80 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 4, 2019 - Departed: TS67, Garden Ridge, TX - Airport: TS67, Kitty Hawk Flying Field, runway 14, 700 × 20 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 37; injuries: none; private; airplane ratings: single-engine land; medical: class 1, without waivers/limitations; seat: left; restraint: 3-point; flight hours: 188 total, 136 in this make and model, 145 as pilot in command, 61 in the last 90 days, 28 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Temperature: 81 °F, dew point 72 °F - Altimeter: 30.03 inHg ## 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 20191005018769A](https://openairdocs.org/incident/20191005018769A), Oct 5, 2019: Johnson-Graber ZENITH CH-701, San Antonio, TX, Substantial damage. 10/05/2019 At 10:30AM CDT. The pilot reported that he taxied to rwy 14 and preformed engine run up without issues. After takeoff the engine experienced a loss… ## Docket (7 files) The files NTSB released with the investigation on March 3, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100399. 1.6 MB in all. - Rotax Field Exam Notes (item 1, .PDF, 144 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40480938&FileExtension=.PDF&FileName=Rotax%20Field%20Exam%20Notes-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 2, .PDF, 144 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482837&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Master.PDF - Photos (item 3, .PDF, 640 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40480940&FileExtension=.PDF&FileName=Photos-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 4, .PDF, 534 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482838&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - FAA SAIB CE-09-35 Carb Icing (item 5, .PDF, 111 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482839&FileExtension=.PDF&FileName=FAA%20SAIB%20CE-09-35%20Carb%20Icing-Master.PDF - CEN20LA005 - Revisions to Factual Report (item 6, .PDF, 43 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482840&FileExtension=.PDF&FileName=CEN20LA005%20-%20Revisions%20to%20Factual%20Report-Master.PDF - Pilot's Statement (item 7, .PDF, 27 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482841&FileExtension=.PDF&FileName=Pilot%27s%20Statement-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.