# NTSB GAA16CA442: Cessna 172, N35408, Anchorage, AK, August 20, 2016

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Data collection · Final report
- Date: August 20, 2016, 12:00 local (20:00 UTC)
- Place: Anchorage, AK
- Coordinates: 61.250831, -149.809448 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=61.2508&lon=-149.8094&mi=10
- Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping)
- Defining event: [Taxi: Prop/jet/rotor blast/suction](https://openairdocs.org/ntsb-events/082)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report December 5, 2016
- Report: Approved by Office Director
- NTSB office: General Aviation Accidents
- Parties: FAA
- NTSB case key (mKey): 93873
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA16CA442
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/93873/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=93873
- Page: https://openairdocs.org/ntsb/GAA16CA442

## Probable cause

The facility's designation of the taxiway for use by maintenance personnel to conduct high thrust tests without appropriate safeguards in place, which led to maintenance personnel conducting high-power, run-up thrust procedures across the active taxiway and resulted in the loss of directional control of a light, single-engine airplane on the taxiway when it encountered a sudden, unexpected blast of engine thrust.

## 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 172R, 37 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=2072401), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md)
- [Design: policy/procedure development](https://openairdocs.org/ntsb-findings/04011025): Organizational issues › Development · Airport (probable cause); cases with it: [Cessna 172R, 1 case](https://openairdocs.org/ntsb-findings/04011025/cases.md?model=2072401), [All aircraft, 17 cases](https://openairdocs.org/ntsb-findings/04011025/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Taxi: Prop/jet/rotor blast/suction](https://openairdocs.org/ntsb-events/082) (defining event); cases with it: [Cessna 172R, 1 case](https://openairdocs.org/ntsb-events/082/sequence.md?model=2072401), [All aircraft, 44 cases](https://openairdocs.org/ntsb-events/082/sequence.md)
- [Taxi: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Cessna 172R, 9 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=2072401), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md)

## Analysis

The flight instructor of a light single-engine airplane reported that while he and the student pilot were on a taxiway under air traffic control (ATC) instruction, the airplane encountered prop wash, originating from a larger (four 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 that was authorized for parking as well as 80% engine(s) power run-ups. The larger turbine-powered airplane was the third in a row a five, of like model airplanes being parked at the location. The light single-engine airplane was not on frequency when the larger turbine-powered airplane was given the clearance, and 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 approximately 80 feet from its original location while taxing behind the larger turbine-powered airplane, which resulted in substantial damage to the firewall. The flight instructor reported that there were no pre impact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. As a safety recommendation the flight instructor stated that the incident could have been prevented with better communications between the tower controllers and the larger turbine-powered airplane's ground personnel.

## Factual narrative

The flight instructor of a light single-engine airplane reported that while he and the student pilot were on a taxiway under air traffic control (ATC) instruction, the airplane encountered prop wash, originating from a larger (four 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 that was authorized for parking as well as 80% engine(s) power run-ups. The larger turbine-powered airplane was the third in a row a five, of like model airplanes being parked at the location. The light single-engine airplane was not on frequency when the larger turbine-powered airplane was given the clearance, and 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 approximately 80 feet from its original location while taxing behind the larger turbine-powered airplane, which resulted in substantial damage to the firewall. The flight instructor reported that there were no pre impact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. As a safety recommendation the flight instructor stated that the incident could have been prevented with better communications between the tower controllers and the larger turbine-powered airplane's ground personnel.

## Aircraft

- Registration: [N35408](https://openairdocs.org/aircraft/N35408), registered now, S/N 17281081 (OpenAirDocs)
- Reported make and model: CESSNA 172 (R)
- Registry model: [Cessna 172R](https://openairdocs.org/model/cessna-172r) (registry code 2072401) (OpenAirDocs)
- Category: Airplane
- Serial number: 17281081
- Year built: 2001
- Airframe hours: 5047.8
- Engines: Lycoming IO-360-L2A 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, June 24, 2016
- Departed: EDF, Anchorage, AK
- Destination: EDF, Anchorage, AK
- Flight plan: Military VFR
- Airport: EDF, Elmendorf Afb
- Equipment: None

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Flight instructor; age 60; injuries: none; flight instructor; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review July 20, 2016; seat: right; flight hours: 9,154 total, 2,000 in this make and model, 3,230 as pilot in command, 100 in the last 90 days, 25 in the last 30 days, 4 in the last 24 hours
- Student pilot; age 27; injuries: none; student; medical: class 3, without waivers/limitations; seat: left; flight hours: 12 total, 12 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 10 statute miles
- Lowest ceiling: 4,000 ft overcast
- Temperature: 61 °F, dew point 54 °F
- Altimeter: 30.04 inHg
- Observed at: PAED

## 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 20160820022919A](https://openairdocs.org/incident/20160820022919A), Aug 20, 2016: Cessna 172R, Anchorage, AK, Substantial damage. Elmendorf afb aka(jber) paed: N35408, a Cessna CE-172, landed without incident at 1330 AKDT, Anchorage, AK, on 8/20/2016. N35408 taxied behind a military C-130…

## Other investigations on N35408 (1)

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.

- [NTSB ANC21LA100](https://openairdocs.org/ntsb/ANC21LA100), Sep 18, 2021: Cessna 172R (N35408), Birchwood, AK, substantial damage. Probable cause: The flight instructor’s inadequate supervision of the student pilot, and student pilot’s improper landing flare, resulting in a hard landing.

## Docket (2 files)

The files NTSB released with the investigation on October 12, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=93873. 2.1 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40445290&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF
- Accident Photo (item 2, .PDF, 184 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40445291&FileExtension=.PDF&FileName=Accident%20Photo-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.

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