sensors Mode-S transponder

A9BFC9

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N727YX · EMBRAER ERJ-170-200 (long wing) · operated by REPUBLIC AIRWAYS INC

Hex
A9BFC9
Octal
52337711
Decimal
11,124,681
Country
US
Tail
N727YX
Type
E75L
No current signal · last broadcast 1d ago
Flights observed
13
Distinct callsigns
8
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A9BFC9.

Country allocation

The ICAO 24-bit address A9BFC9 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 8 distinct

Callsign Airline Flights Last seen
RPA3683 - 3 2026-04-13
RPA3701 Republic Airlines 2 2026-04-13
RPA3523 Republic Airlines 2 2026-04-13
RPA3420 - 2 2026-04-13
RPA3709 - 1 2026-04-13
RPA3605 - 1 2026-04-13
RPA3534 - 1 2026-04-13
RPA3499 - 1 2026-04-12

Recent flights last 13

DateFlightRouteTakeoffLandingDuration
2026-04-13 RPA3534 - Apr 13, 22:18 UTCApr 13, 23:25 UTC1h 7m
2026-04-13 RPA3523 MSY → EWR Apr 13, 19:50 UTCApr 13, 20:50 UTC1h 0m
2026-04-13 RPA3523 MSY → EWR Apr 13, 19:37 UTCApr 13, 21:13 UTC1h 36m
2026-04-13 RPA3683 - Apr 13, 16:15 UTCApr 13, 17:55 UTC1h 40m
2026-04-13 RPA3683 - Apr 13, 15:50 UTCApr 13, 17:55 UTC2h 5m
2026-04-13 RPA3683 - Apr 13, 15:42 UTCApr 13, 17:51 UTC2h 9m
2026-04-13 RPA3605 - Apr 13, 12:44 UTCApr 13, 14:28 UTC1h 44m
2026-04-13 RPA3709 - Apr 13, 10:22 UTCApr 13, 10:58 UTC36m
2026-04-13 RPA3701 GSP → EWR Apr 13, 02:35 UTCApr 13, 02:55 UTC20m
2026-04-13 RPA3701 GSP → EWR Apr 13, 01:47 UTCApr 13, 02:19 UTC32m
2026-04-13 RPA3420 - Apr 13, 00:20 UTCApr 13, 00:30 UTC10m
2026-04-12 RPA3420 - Apr 12, 23:55 UTCApr 13, 00:30 UTC35m
2026-04-12 RPA3499 - Apr 12, 17:55 UTCApr 12, 20:15 UTC2h 20m

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 N727YX page for operator, model, and routing details .

Mode-S A9BFC9 frequently asked

What is Mode-S code A9BFC9?
A9BFC9 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N727YX.
Where is Mode-S A9BFC9 registered?
Mode-S code A9BFC9 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 A9BFC9 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 A9BFC9, octal 52337711, decimal 11,124,681.
What flights does A9BFC9 operate?
Mode-S A9BFC9 has broadcast 8 distinct callsigns, including RPA3683, RPA3701, RPA3523, RPA3420, RPA3709.