sensors Mode-S transponder

A3900E

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N329DD · operated by AMERICAN AIRLINES INC

Hex
A3900E
Octal
50710016
Decimal
10,719,246
Country
US
Tail
N329DD
Type
E75L
No current signal · last broadcast 1d ago
Flights observed
11
Distinct callsigns
7
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A3900E.

Country allocation

The ICAO 24-bit address A3900E falls within the block assigned to United States (US) by ICAO Annex 10, Volume III. Every aircraft registered in United States receives a permanent address from this block at the time of registration; the address stays with the airframe even if the aircraft is re-registered to a different operator within the country.

Callsign history 7 distinct

Callsign Airline Flights Last seen
ENY4304 Envoy Air 2 2026-04-13
ENY4265 - 2 2026-04-13
ENY4082 Envoy Air 2 2026-04-13
ENY3448 - 2 2026-04-13
ENY4061 - 1 2026-04-13
ENY3989 Envoy Air 1 2026-04-12
ENY3756 - 1 2026-04-13

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-13 ENY3756 - Apr 13, 23:15 UTCApr 13, 23:40 UTC25m
2026-04-13 ENY3448 - Apr 13, 21:10 UTCApr 13, 21:40 UTC30m
2026-04-13 ENY3448 - Apr 13, 18:32 UTCApr 13, 21:40 UTC3h 8m
2026-04-13 ENY4304 DFW → TXK Apr 13, 16:25 UTCApr 13, 16:50 UTC25m
2026-04-13 ENY4304 DFW → TXK Apr 13, 14:40 UTCApr 13, 15:00 UTC20m
2026-04-13 ENY4265 - Apr 13, 11:55 UTCApr 13, 12:20 UTC25m
2026-04-13 ENY4265 - Apr 13, 10:46 UTCApr 13, 12:31 UTC1h 45m
2026-04-13 ENY4061 - Apr 13, 02:10 UTCApr 13, 03:50 UTC1h 40m
2026-04-13 ENY4082 LAN → ORD Apr 13, 00:20 UTCApr 13, 00:55 UTC35m
2026-04-12 ENY4082 LAN → ORD Apr 12, 23:59 UTCApr 13, 00:53 UTC54m
2026-04-12 ENY3989 ORD → CVG Apr 12, 17:45 UTCApr 12, 20:15 UTC2h 30m

About Mode-S

A Mode-S transponder code (also called an "ICAO 24-bit address" or "hex code") is a 6-character hexadecimal identifier permanently assigned to an aircraft when it's first registered. Unlike callsigns (which change with each flight) or registrations (which can change if an aircraft is sold internationally), the Mode-S address stays with the airframe for the life of the aircraft in that country.

Every ADS-B transmission from an aircraft includes its Mode-S address, making it the most reliable way to identify a specific airframe. Flight-tracking services like Apparatus use the Mode-S address as the primary key for tying position broadcasts, callsigns, and ownership records together.

Prefer a tail-number view? See the N329DD page for operator, model, and routing details .

Mode-S A3900E frequently asked

What is Mode-S code A3900E?
A3900E is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N329DD.
Where is Mode-S A3900E registered?
Mode-S code A3900E is allocated to United States (US). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is A3900E broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A3900E, octal 50710016, decimal 10,719,246.
What flights does A3900E operate?
Mode-S A3900E has broadcast 7 distinct callsigns, including ENY4304, ENY4265, ENY4082, ENY3448, ENY4061.