N551X — 2021 Thomas N Helm SONEX ONEX
Active registrationChecked against FAA & NTSB records · as of Jul 16, 2026
N551X appears in 1 NTSB accident record (most recent 2009, 1 fatality). Registration and accident data compiled from public FAA and NTSB records as of Jul 16, 2026.
Aircraft record
- Serial number
- ONX0137
- Manufacturer
- Thomas N Helm
- Model
- SONEX ONEX
- Year
- 2021
- Category
- Fixed wing single-engine
- Engine
- Aeroconver Aerovee
- Registration
- Active
- Registered to
- Helm Thomas N — Neenah, WI
Accident & incident history
A loss of engine power due to contamination and clogging of the fuel system by a post-assembly fuel tank sealant.
Registration timeline
Ownership and registration events for this airframe (the 2021 Thomas N Helm SONEX ONEX).
- May 12, 2020registered — Helm Thomas N
Earlier aircraft on this N-number
The tail number N551X was previously assigned to different aircraft. A registration number can be reused across unrelated airframes over decades — these are not the 2021 Thomas N Helm SONEX ONEX above.
- until Apr 12, 20122002 Eldredge Kevin S51 (s/n 076)
- until Jul 10, 1995Boeing A75N1 (s/n 75267)
Frequently asked
- Has N551X been in an accident?
- Yes. N551X appears in 1 NTSB accident record, the most recent in 2009.
- What kind of aircraft is N551X?
- N551X is a 2021 Thomas N Helm SONEX ONEX (fixed wing single-engine), serial number ONX0137.
- Who is N551X registered to?
- N551X is registered to Helm Thomas N of Neenah, WI. Registration status: active.
- Has N551X been in a fatal accident?
- An NTSB record for N551X (ERA09LA184) is classified with a fatal highest injury level.
The full N551X report
$12 $29 launch pricing
- Full NTSB investigation narratives for all 1 record — the complete text, not just the cause line
- Pre-buy question list generated from this aircraft’s actual records
- Complete registration & deregistration timeline, print-ready
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