Single-engine piston

N551X

2021 Homebuilt Sonex Onex

Registered No accidents on file
Built
2021
Serial
ONX0137
Class
Single-engine piston
Engines
Aeroconver AEROVEE
Status
Current as of October 2026
Registered owner
Individual · sign in to see
Based
Neenah, WI
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Registration record

N551X on the FAA register

Type
2021 Homebuilt Sonex Onex
Serial
ONX0137
Engines
Aeroconver AEROVEE
Registered owner
Individual — the name of an individual registrant is shown to signed-in users. Sign in
Neenah, WI
Certificate issued
2020-05-12
Airworthiness date
2021-06-17
Registration expires
2027-05-31
Airworthiness class
Experimental · amateur-built
Mode S (hex)
A7052F
Mode S (octal)
51602457
Seats (type)
1
Weight class
up to 12,499 lb
Kit
Sonex Aircraft Llc ONEX
Status
Current as of October 2026
Registry history

Timeline

  • 2027-05-31
    Registration expires (renewal due).
  • 2021-06-17
    Airworthiness date on the current FAA record (experimental category (amateur-built)).
  • 2020-05-12
    Certificate of registration issued as N551X to the current registrant.
  • 2012-04-12
    N551X previously assigned to a Homebuilt S51 (s/n 076); cancelled.
  • 1995-07-10
    N551X previously assigned to a Boeing/Stearman A75 N1 / PT-17 Kaydet (s/n 75267); cancelled.
Overview

About N551X

N551X is a 2021 Homebuilt Sonex Onex, serial number ONX0137. It is registered to an individual in Neenah, Wisconsin. The current certificate of registration was issued on May 12, 2020 and expires on May 31, 2027.

The FAA aircraft reference file describes the type as a single-engine piston, one Aeroconver AEROVEE engine and 1 seats. Its airworthiness certificate is experimental category (amateur-built), dated June 17, 2021.

No NTSB accident or incident reports and no FAA preliminary notices are on file for this airframe as N551X. 2 earlier records involve a different aircraft that carried the same N-number.

Safety record

Accident & incident history

2009-03-06 Accident · Ocala, FL Damage: Substantial Fatal injury NTSB · ERA09LA184
Reported aircraft: Kevin Eldredge Stewart — a different aircraft that carried the N551X registration before this airframe.
Probable cause: A loss of engine power due to contamination and clogging of the fuel system by a post-assembly fuel tank sealant.
1975-06-06 Accident · Bowling Green,Ky, 17 Damage: Substantial NTSB · 3 1657
Reported aircraft: Cessna 320B — a different aircraft that carried the N551X registration before this airframe.
Probable cause: STABILIZE ACFT IN PITCH MODE THRU ELEV TRIM.

Sources: NTSB aviation accident database and CAROL case system, FAA preliminary accident & incident notices. Search accident records

Same state

Other aircraft registered in Wisconsin

N55170
1941 Boeing/Stearman A75 N1
N551DR
2025 51 Heritage SW-51
N551TL
Bell 505 Jet Ranger X
N5522U
1969 Piper Cherokee 140
N552SM
1946 ERCO / Forney / Alon Ercoupe 415C
N5531R
1965 Cessna 172 Skyhawk
All 6,164 aircraft registered in Wisconsin →
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Browse: Aircraft registered in Wisconsin· Registry by state· FAA registry stats

Data: FAA Aircraft Registry (October 2026), including deregistered aircraft; NTSB and FAA accident data; fyiAero listing history. Individual owners' names are shown to signed-in users and street addresses are never shown. Type figures are published specifications, not this aircraft's.