Registration pending
N4121D — 1957 HELIO H-391B
Registry aircraft record
HELIO H-391B model hub
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About N4121D
What aircraft is N4121D?
N4121D is a 1957 HELIO H-391B listed on the FAA (United States) register.
Is N4121D currently registered?
Not yet — the FAA (United States) lists N4121D as registration pending (registry data updated 2026-10-22).
How many seats and engines does HELIO H-391B have?
The HELIO H-391B has 4 seats and 1 engine.