DCA21LA094 · Bell APT70
Bell Helicopter Textron Bell APT70 · Accident: flight control system malfunction/failure en route
Event
- NTSB case
- DCA21LA094
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- Event fatalities
- Unknown
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Government
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Bell APT70
- Aircraft type
- Bell APT70
- Category
- Powered-Lift
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N314AQ
- Operator
- Bell Helicopter Textron
- Onboard fatalities
- Unknown
- Route
- From not recordedTo not recorded
- Aircraft age
- About 1 year (built 2020)
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Public Aircraft
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Flight control system malfunction/failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
No findings designated as a cause are recorded in the NTSB data yet.
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
According to the operator/manufacturer, the flight was a demonstration for a component of the U.S. Army in a remote area on the grounds of Fort Benning, Georgia. The APT-70 is an unmanned aircraft with vertical take-off and landing (VTOL) capability. Takeoff and landing is conducted in a “tail-sitter” configuration and lifts off with four quad-rotor propellors providing powered lift. The aircraft transitions to forward flight using the propellors for thrust, and a bi-wing configuration for lift.
During the flight, the Electronic Speed Controller (ESC) on the number 1 motor faulted, resulting in a loss of thrust from that motor. The aircraft flight controller automatically reduced thrust on the opposite motor to maintain stable attitude control, which caused an overall reduction in thrust and led to a descent and to impact with trees. The aircraft was substantially damaged and there were no injuries.
The aircraft is capable of entering a hover and controlled descent in the event of a failed motor; however, this maneuver requires crew action. The impact with the trees occurred about 5 seconds after the failure, before the pilot could take action. The operator/manufacturer identified an ambiguous paragraph in their safety checklist regarding the appropriate response to ESC failure. The examination of flight data and the ESC by the operator/manufacturer identified a cracked ceramic capacitor in the ESC circuitry.
Probable cause
failure of an electronic speed controller that resulted in a descent and impact with trees.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DCA21LA094
- Event ID
- 20210311102742
- Case number
- DCA21LA094
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 86b24e31bca7264cebabf1e296b7e97842e38ddf613dafad4cf49aa411ccbba6; retrieved 2026-09-16T13:48:23.875Z.