sensors Mode-S transponder

AAB431

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N789YX · EMBRAER ERJ-170-200 (long wing) · operated by REPUBLIC AIRWAYS INC

Hex
AAB431
Octal
52532061
Decimal
11,187,249
Country
US
Tail
N789YX
Type
E75L
No current signal · last broadcast 1d ago
Flights observed
8
Distinct callsigns
5
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S AAB431.

Country allocation

The ICAO 24-bit address AAB431 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 5 distinct

Callsign Airline Flights Last seen
RPA3497 - 3 2026-04-13
RPA3653 - 2 2026-04-13
RPA3661 - 1 2026-04-13
RPA3471 - 1 2026-04-12
RPA3453 Republic Airlines 1 2026-04-13

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-13 RPA3453 GSP → EWR Apr 13, 21:30 UTCApr 13, 22:40 UTC1h 10m
2026-04-13 RPA3497 - Apr 13, 19:50 UTCApr 13, 20:25 UTC35m
2026-04-13 RPA3497 - Apr 13, 18:53 UTCApr 13, 20:24 UTC1h 31m
2026-04-13 RPA3497 - Apr 13, 19:18 UTCApr 13, 20:22 UTC1h 4m
2026-04-13 RPA3661 - Apr 13, 16:40 UTCApr 13, 18:10 UTC1h 30m
2026-04-13 RPA3653 - Apr 13, 13:24 UTCApr 13, 14:29 UTC1h 5m
2026-04-13 RPA3653 - Apr 13, 13:24 UTCApr 13, 14:20 UTC56m
2026-04-12 RPA3471 - Apr 12, 17:50 UTCApr 12, 19:40 UTC1h 50m

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 N789YX page for operator, model, and routing details .

Mode-S AAB431 frequently asked

What is Mode-S code AAB431?
AAB431 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N789YX.
Where is Mode-S AAB431 registered?
Mode-S code AAB431 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 AAB431 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 AAB431, octal 52532061, decimal 11,187,249.
What flights does AAB431 operate?
Mode-S AAB431 has broadcast 5 distinct callsigns, including RPA3497, RPA3653, RPA3661, RPA3471, RPA3453.