# NTSB ANC20CA014: Cessna 172, N22905, Tokyo, Japan, December 15, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: December 15, 2019 - Place: Tokyo, Japan - Coordinates: 35.741111, 139.346664 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.7411&lon=139.3467&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Defining event: [Taxi-to runway: Prop/jet/rotor blast/suction](https://openairdocs.org/ntsb-events/082) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report June 29, 2020 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 100807 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC20CA014 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100807/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100807 - Page: https://openairdocs.org/ntsb/ANC20CA014 ## Probable cause The airplane’s encounter with prop wash while taxiing behind a larger airplane that was conducting a high-power engine run on the same taxiway. Contributing to the accident was the air traffic controller’s failure to inform the smaller airplane’s pilot about the larger airplane pilot’s intentions. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Cessna 172M, 59 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=2072418), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Environmental issues](https://openairdocs.org/ntsb-findings/03030000): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Cessna 172M, 1 case](https://openairdocs.org/ntsb-findings/03030000/cases.md?model=2072418), [All aircraft, 57 cases](https://openairdocs.org/ntsb-findings/03030000/cases.md) - [Communication (personnel): lack of communication](https://openairdocs.org/ntsb-findings/02063510): Personnel issues › Task performance · ATC personnel (probable cause); cases with it: [Cessna 172M, 1 case](https://openairdocs.org/ntsb-findings/02063510/cases.md?model=2072418), [All aircraft, 84 cases](https://openairdocs.org/ntsb-findings/02063510/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Taxi-to runway: Prop/jet/rotor blast/suction](https://openairdocs.org/ntsb-events/082) (defining event); cases with it: [Cessna 172M, 2 cases](https://openairdocs.org/ntsb-events/082/sequence.md?model=2072418), [All aircraft, 44 cases](https://openairdocs.org/ntsb-events/082/sequence.md) - [Taxi-to runway: Roll over](https://openairdocs.org/ntsb-events/097); cases with it: [Cessna 172M, 2 cases](https://openairdocs.org/ntsb-events/097/sequence.md?model=2072418), [All aircraft, 261 cases](https://openairdocs.org/ntsb-events/097/sequence.md) ## Analysis The operator's operations chief reported that an air traffic controller instructed the flight instructor and pilot to taxi to a taxiway and that, subsequently, the airplane encountered prop wash from a larger airplane on the same taxiway, which flipped the airplane onto its right side and resulted in substantial damage to the forward wing spar. The larger airplane's pilot reported that he was conducting a high-power engine run on the same taxiway. The air traffic controller did not tell the pilots in the smaller airplane at any time while they were taxiing about the larger airplane's intentions. The pilot of the larger airplane reported that all requests for engine start, taxi, and high-power engine runs were coordinated with air traffic control (ATC). He added that they had to reposition due to a tailwind and that he had made a radio call to ATC and acknowledged that they had repositioned on the ramp to face into the wind. He added that he heard the lighter airplane receive a taxi clearance but did not hear any communications questioning the larger airplane's status or position with respect to any potential impact on aircraft taxiing behind them on the taxiway. He became aware of the lighter airplane's situation after the event when its pilot made a radio call to ground control. ## Factual narrative The Aero Club operations chief reported that, the flight instructor and pilot were on a taxiway under air traffic control (ATC) instruction, the airplane encountered prop wash, originating from a larger (twin engine) turbine-powered airplane performing a maintenance engine(s) run-up. The maintenance run-up was performed in a location adjacent to the active taxiway. The light single-engine airplane was not told by ATC at any time during their taxi of the larger turbine-powered airplane's intentions. Subsequently, the light single-engine airplane was blown from its location while taxing behind the larger turbine-powered airplane, which resulted in substantial damage to the forward wing-spar. The Aero Club operations chief reported that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. The pilot of the larger turbine-powered airplane reported that, all requests for engine start, taxi, and high power runs were coordinated with ATC. He added that they had to reposition due to tailwinds, however a radio call was made to ATC and acknowledged that they had repositioned on the ramp to face into the wind. He added that he heard the light single-engine airplane receive a taxi clearance but did not hear any communications questioning the larger turbine-powered airplane's status or position with respect to any potential impact on aircraft taxiing behind them on the taxiway. He became aware of the light single-engine airplane's situation after the event when the pilot of the light single-engine airplane made a radio call to ground control. ## Aircraft - Registration: [N22905](https://openairdocs.org/aircraft/N22905), registered now, S/N 17264078, built 1974 (OpenAirDocs) - Reported make and model: Cessna 172 (M) - Registry model: [Cessna 172M](https://openairdocs.org/model/cessna-172m) (registry code 2072418) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17264078 - Year built: 1974 - Airframe hours: 9142.7 - Engines: Lycoming O-360-A4M 180 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Yokota Aero Club - Registered owner: Yokota Aero Club - Airworthiness certificate: Standard, Normal - Last inspection: Annual, December 12, 2019 - Flight plan: Company VFR - Airport: RJTY, Yokota Air Base - Equipment: Electronic flight bag or handheld device, Electronic multifunction display, Electronic primary flight display, Stall warning system, ADS-B, Angle of attack indicator, Auto-pilot ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 40; injuries: none; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; seat: right; restraint: 4-point; flight hours: 697 total, 227 in this make and model - Pilot; age 29; injuries: none; military, commercial; instrument ratings: helicopter; medical: class 1, without waivers/limitations; seat: left; restraint: 4-point; flight hours: 671 total, 51 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 50° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 50 °F, dew point 25 °F - Altimeter: 30.32 inHg - Observed at: RJTY, 1 nm away ## Docket (3 files) The files NTSB released with the investigation on April 15, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100807. 1.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 469 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482429&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - DHC8 Pilot Statement (item 2, .PDF, 186 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482430&FileExtension=.PDF&FileName=DHC8%20Pilot%20Statement-Master.PDF - Accident Picture (item 3, .PDF, 486 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482431&FileExtension=.PDF&FileName=Accident%20Picture-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.