ERA21LA366 · Sproul Keith A 83K-16
Sproul Keith A 83K-16 · Accident: collision during takeoff/landing
From Post Mills Airport (2B9) to an unrecorded destination
Event
- NTSB case
- ERA21LA366
- 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
- General aviation
- 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
Sproul Keith A 83K-16
- Aircraft type
- Sproul Keith 83
- Category
- Balloon
- 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
- N83KX
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Post Mills Airport (2B9), Post Mills, VTTo not recorded
- Aircraft age
- About 2 years (built 2019)
- 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
- Part 91: General Aviation
- 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
- Landing
- 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
- Collision during takeoff/landing
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Tree(s)
- 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
- Aircraft › Aircraft oper/perf/capability
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot and passenger departed early for a day of ballooning. As they approached the selected landing area, the pilot started a descent to slow the balloon in slower winds. As the balloon neared the treetops, the wind direction shifted slightly, which resulted in the balloon colliding with a tree. During the flight, and unbeknownst to the pilot, his lapbelt had become unsecured, and after the impact with the tree, he slid forward in the seat and held on to the uprights of the chair to prevent falling from the balloon. In this position the pilot could no longer control the balloon and remained holding onto the frame as the balloon went through the trees, which resulted in substantial damage to the envelope and frame. The pilot reported that the balloon had no preimpact mechanical malfunctions or failures that would have precluded normal operation.
Probable cause
The pilot's failure to secure himself to the balloon seat which resulted in a loss of control of the balloon.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA21LA366
- Event ID
- 20210916103890
- Case number
- ERA21LA366
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (5)
- 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, cause areas. 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: 02acc4f08e52b86b47fe7367d73bcac28b0964fa5fb7511310a269ee20ed6f50; retrieved 2026-09-16T14:32:48.209Z.
- Corrected after a review of the NTSB narrative, which states these values explicitly: departure. The airport name was placed in the city slot; 2B9 is Post Mills Airport, whose city is Post Mills, Vermont.