# NTSB DCA20CA028: General Atomics MQ-9, N341HK, Palmdale, CA, November 25, 2019

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Data collection · Final report
- Date: November 25, 2019, 10:52 local (18:52 UTC)
- Place: Palmdale, CA
- Coordinates: 34.571109, -117.668891
- Nearby events: https://openairdocs.org/map.md?lat=34.5711&lon=-117.6689&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Defining event: [Landing: Runway excursion](https://openairdocs.org/ntsb-events/300)
- Highest injury: No injuries
- Status: Completed, report March 27, 2020
- Report: Approved by Office Director
- NTSB office: Major Investigations Division
- NTSB case key (mKey): 100625
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DCA20CA028
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100625/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100625
- Page: https://openairdocs.org/ntsb/DCA20CA028

## Probable cause

Incorrect control inputs by the student pilot during a crosswind landing, resulting in control saturation and a runway excursion.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Student/instructed pilot (probable cause); cases with it: [General Atomics Aero Systems UHK97000-15, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=061005D), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)
- [Wind: crosswind](https://openairdocs.org/ntsb-findings/03034040): Environmental issues › Conditions/weather/phenomena · Response/compensation (probable cause); cases with it: [General Atomics Aero Systems UHK97000-15, 1 case](https://openairdocs.org/ntsb-findings/03034040/cases.md?model=061005D), [All aircraft, 1,008 cases](https://openairdocs.org/ntsb-findings/03034040/cases.md)
- [Performance/control parameters: crosswind correction](https://openairdocs.org/ntsb-findings/01062030): Aircraft › Aircraft oper/perf/capability · Incorrect use/operation (probable cause); cases with it: [General Atomics Aero Systems UHK97000-15, 1 case](https://openairdocs.org/ntsb-findings/01062030/cases.md?model=061005D), [All aircraft, 184 cases](https://openairdocs.org/ntsb-findings/01062030/cases.md)

## Sequence of events

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

- [Landing: Runway excursion](https://openairdocs.org/ntsb-events/300) (defining event); cases with it: [General Atomics Aero Systems UHK97000-15, 1 case](https://openairdocs.org/ntsb-events/300/sequence.md?model=061005D), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md)

## Analysis

On November 25, 2019, at 1052 Pacific standard time (PST), N341HK a General Atomics Aeronautical Systems (GA-ASI) MQ-9 unmanned aircraft system (UAS), sustained substantial damage after departing runway 26 when landing during a training flight at the Gray Butte airport, Palmdale, California. The flight was operated by GA-ASI as a routine pilot and sensor operator training flight. The flight departed Gray Butte, and was conducted under the provisions of 14 CFR Part 91 and an FAA Certificate of Authorization (COA). There were no injuries or other damage. At 1058 PST, the automated surface observation system at Gray Butte reported clear skies with wind from 260 at 18 knots, variable from 220 degrees to 290 degrees, with a peak wind of 270 degrees at 28 knots. According to the operator/manufacturer, the student pilot was pilot-flying and the aircraft touched down at 79 knots indicated airspeed (KIAS) crabbed to the left approximately 5 degrees, consistent with a 7 knot crosswind component from the left. Upon touchdown, the aircraft began drifting to the left with the nose wheel off the ground. Over approximately the next 15 seconds, increasing right rudder was applied as the aircraft continued to drift left. Pitch stick position was +9 degrees (with pitch trim set to -5 degrees, pitch command was +4 degrees, 2 degrees above recommended pitch in the Flight Manual). The throttle was not moved to ground idle or reverse. A go-around was initiated, but the aircraft departed the runway before the engine could respond. Operator/manufacturer examination of data logs systems information revealed that since the autopilot prioritizes pitch control over yaw control for movement of the ruddervators, the atypically high pitch command limited the ruddervator authority available for yaw control. With the ruddervators saturated in pitch, yaw authority from the ventral rudder alone was insufficient to effect a right yaw. The flight manual did not have any information about the possibility of pitch control prioritization resulting in limited yaw authority.

## Factual narrative

On November 25, 2019, at 1052 Pacific standard time (PST), N341HK a General Atomics Aeronautical Systems (GA-ASI) MQ-9 unmanned aircraft system (UAS), sustained substantial damage after departing runway 26 when landing during a training flight at the Gray Butte airport, Palmdale, California. The flight was operated by GA-ASI as a routine pilot and sensor operator training flight. The flight departed Gray Butte, and was conducted under the provisions of 14 CFR Part 91 and an FAA Certificate of Authorization (COA). There were no injuries or other damage. At 1058 PST, the automated surface observation system at Gray Butte reported clear skies with wind from 260 at 18 knots, variable from 220 degrees to 290 degrees, with a peak wind of 270 degrees at 28 knots. According to the operator/manufacturer, the student pilot was pilot-flying and the aircraft touched down at 79 knots indicated airspeed (KIAS) crabbed to the left approximately 5 degrees, consistent with a 7 knot crosswind component from the left. Upon touchdown, the aircraft began drifting to the left with the nose wheel off the ground. Over approximately the next 15 seconds, increasing right rudder was applied as the aircraft continued to drift left. Pitch stick position was +9 degrees (with pitch trim set to -5 degrees, pitch command was +4 degrees, 2 degrees above recommended pitch in the Flight Manual). The throttle was not moved to ground idle or reverse. A go-around was initiated, but the aircraft departed the runway before the engine could respond. Operator/manufacturer examination of data logs systems information revealed that since the autopilot prioritizes pitch control over yaw control for movement of the ruddervators, the atypically high pitch command limited the ruddervator authority available for yaw control. With the ruddervators saturated in pitch, yaw authority from the ventral rudder alone was insufficient to effect a right yaw. The flight manual did not have any information about the possibility of pitch control prioritization resulting in limited yaw authority.

## Aircraft

- Registration: [N341HK](https://openairdocs.org/aircraft/N341HK), registered now, S/N FC341, built 2015 (OpenAirDocs)
- Reported make and model: General Atomics MQ-9 (5)
- Registry model: [General Atomics Aero Systems UHK97000-15](https://openairdocs.org/model/general-atomics-aero-systems-uhk97000-15) (registry code 061005D) (OpenAirDocs)
- Registry engine: [Honeywell TPE331-10 series](https://openairdocs.org/engine/honeywell-tpe331-10-series) (registry code 33899, turbo-prop) (OpenAirDocs)
- Category: Airplane, unmanned
- Serial number: FC341
- Year built: 2014
- Airframe hours: 1979.9
- Engines: Honeywell International Inc. turbo prop
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: General Atomics Aeronautical Systems Inc
- Registered owner: General Atomics Aero Systems
- Airworthiness certificate: Certificate of authorization or waiver (COA)
- Last inspection: October 22, 2019
- Departed: 04CA, Palmdale, CA
- Destination: 04CA, Palmdale, CA
- Airport: 04CA, Gray Butte, runway 26, 8,000 × 150 ft, asphalt
- Equipment: Electronic primary flight display, Heads up display, Stall warning system, Video recording device, Angle of attack indicator, Data recorder, Electronic multifunction display

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Student pilot; age 28; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review September 19, 2018; seat: left; flight hours: 987.7 total, 315 in this make and model
- Flight instructor; injuries: none; flight instructor, commercial; seat: rear; restraint: none; flight hours: 2,906 total

## Weather

- Conditions: Visual (VMC), Day
- Wind: variable at 18 knots
- Visibility: 10 statute miles
- Altimeter: 29.85 inHg
- Observed at: KGXA

## 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 20191125024619A](https://openairdocs.org/incident/20191125024619A), Nov 25, 2019: General Atomics Aero Systems UHK97000-15, Palmdale, CA, Substantial damage. Student pilot touched down on centerline then started veering to the left. Instructor pilot instructed the student to apply right rudder multiple times. The…

## Docket (1 files)

The files NTSB released with the investigation on March 31, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100625. 3.8 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40481728&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-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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