Pistons/HELIO/H-391B/N4123D

N4123D — 1957 HELIO H-391B

Registry aircraft record

✦FAA Registry Record

N-NumberN4123D

Serial number042

ManufacturerHELIO

ModelH-391B

Year built1957

RegistrantTHUN KARL J

Registry statusRegistered (V)

RegistrationRegistration current · expires 28 Feb 2030

AirworthinessAirworthiness certificate on file

Last action2023-10-07

Source: FAA (United States) · updated Oct 22, 2026

One of 16 active HELIO H-391Bs across the 4 registries BuyJet tracks. Registry record last updated Oct 22, 2026.

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About N4123D

N4123D is a 1957 HELIO H-391B registered with the FAA (United States).

Yes — the FAA (United States) lists N4123D as registered (registry data updated 2026-10-22).

The HELIO H-391B has 4 seats and 1 engine.