Apparatus

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sensors Mode-S transponder

A9FFEB

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N743YX · EMBRAER ERJ-170-200 (long wing) · operated by UNITED AIRLINES INC

Hex
A9FFEB
Octal
52377753
Decimal
11,141,099
Country
US
Tail
N743YX
Type
E75L
No current signal · last broadcast Jul 26, 21:10 UTC
Flights observed
620
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:10 UTC

Last known position

Most recent position reported by Mode-S A9FFEB.

Country allocation

The ICAO 24-bit address A9FFEB 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 20 distinct

Callsign Airline Flights Last seen
RPA3450 - 11 2026-07-13
RPA3707 - 9 2026-07-16
RPA3300 Republic Airlines 9 2026-05-14
RPA3580 - 8 2026-06-28
RPA3415 - 8 2026-07-19
RPA3696 Republic Airlines 7 2026-07-26
RPA3703 - 6 2026-07-05
RPA3620 - 6 2026-06-14
RPA3549 Republic Airlines 6 2026-07-08
RPA3514 Republic Airlines 6 2026-06-01
RPA3494 - 6 2026-07-09
RPA3464 - 6 2026-07-19
RPA3420 - 6 2026-07-06
RPA3401 Republic Airlines 6 2026-07-26
RPA3659 - 5 2026-07-18
RPA3653 Republic Airlines 5 2026-06-15
RPA3647 - 5 2026-07-09
RPA3607 - 5 2026-06-17
RPA3564 Republic Airlines 5 2026-07-23
RPA3561 - 5 2026-07-08

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 RPA3401 BNA → EWR Jul 26, 20:00 UTCJul 26, 21:05 UTC1h 5m
2026-07-26 RPA3646 MEM → EWR Jul 26, 16:20 UTCJul 26, 17:50 UTC1h 30m
2026-07-26 RPA3696 EWR → CLT Jul 26, 13:40 UTCJul 26, 14:35 UTC55m
2026-07-26 RPA3696 EWR → CLT Jul 26, 13:17 UTCJul 26, 14:29 UTC1h 12m
2026-07-25 RPA3598 RDU → EWR Jul 25, 23:15 UTCJul 25, 23:55 UTC40m
2026-07-25 RPA3473 SAV → EWR Jul 25, 21:25 UTCJul 25, 21:55 UTC30m
2026-07-25 RPA3473 SAV → EWR Jul 25, 21:12 UTCJul 25, 21:38 UTC26m
2026-07-25 RPA3478 EWR → ILM Jul 25, 19:50 UTCJul 25, 20:20 UTC30m
2026-07-25 RPA3485 DCA → EWR Jul 25, 15:30 UTCJul 25, 16:30 UTC1h 0m
2026-07-25 RPA3417 EWR → JAX Jul 25, 12:45 UTCJul 25, 14:15 UTC1h 30m
2026-07-25 RPA3608 EWR → PHL Jul 25, 10:20 UTCJul 25, 11:20 UTC1h 0m
2026-07-25 RPA3719 IND → EWR Jul 25, 02:15 UTCJul 25, 03:25 UTC1h 10m
2026-07-24 RPA3565 BNA → EWR Jul 24, 23:35 UTCJul 25, 00:35 UTC1h 0m
2026-07-24 RPA3579 CVG → EWR Jul 24, 21:53 UTCJul 24, 22:13 UTC20m
2026-07-24 RPA3579 CVG → EWR Jul 24, 21:40 UTCJul 24, 22:15 UTC35m
2026-07-24 RPA3401 BNA → EWR Jul 24, 19:05 UTCJul 24, 20:20 UTC1h 15m
2026-07-24 RPA3646 MEM → EWR Jul 24, 16:20 UTCJul 24, 18:05 UTC1h 45m
2026-07-24 RPA3461 CVG → EWR Jul 24, 12:40 UTCJul 24, 13:45 UTC1h 5m
2026-07-24 RPA3477 EWR → SAV Jul 24, 02:45 UTCJul 24, 03:35 UTC50m
2026-07-23 RPA3714 EWR → ROC Jul 23, 23:30 UTCJul 24, 00:50 UTC1h 20m
2026-07-23 RPA3589 ROC → EWR Jul 23, 20:55 UTCJul 23, 22:15 UTC1h 20m
2026-07-23 RPA3708 ORF → EWR Jul 23, 17:30 UTCJul 23, 19:50 UTC2h 20m
2026-07-23 RPA3708 ORF → EWR Jul 23, 17:26 UTCJul 23, 19:45 UTC2h 19m
2026-07-23 RPA3587 EWR → GSO Jul 23, 14:35 UTCJul 23, 16:20 UTC1h 45m
2026-07-23 RPA3470 EWR → JAX Jul 23, 11:25 UTCJul 23, 13:05 UTC1h 40m
2026-07-23 RPA3564 CMH → EWR Jul 23, 02:45 UTCJul 23, 04:35 UTC1h 50m
2026-07-23 RPA3564 CMH → EWR Jul 23, 02:25 UTCJul 23, 04:30 UTC2h 5m
2026-07-22 RPA3680 IAD → YUL Jul 22, 23:40 UTCJul 23, 00:50 UTC1h 10m
2026-07-22 RPA3454 SDF → EWR Jul 22, 21:25 UTCJul 22, 22:25 UTC1h 0m
2026-07-22 RPA3573 DCA → EWR Jul 22, 17:35 UTCJul 22, 19:25 UTC1h 50m
2026-07-22 RPA3573 DCA → EWR Jul 22, 17:38 UTCJul 22, 19:23 UTC1h 45m
2026-07-22 RPA3630 EWR → YUL Jul 22, 14:23 UTCJul 22, 16:23 UTC2h 0m
2026-07-22 RPA3630 EWR → YUL Jul 22, 14:15 UTCJul 22, 16:25 UTC2h 10m
2026-07-21 RPA3423 CMH → EWR Jul 21, 15:45 UTCJul 21, 17:15 UTC1h 30m
2026-07-21 RPA3423 CMH → EWR Jul 21, 10:10 UTCJul 21, 13:55 UTC3h 45m
2026-07-21 RPA3472 EWR → CLT Jul 21, 00:00 UTCJul 21, 01:20 UTC1h 20m
2026-07-20 RPA3705 YYZ → EWR Jul 20, 19:30 UTCJul 20, 20:30 UTC1h 0m
2026-07-20 RPA3490 ORF → EWR Jul 20, 17:05 UTCJul 20, 18:05 UTC1h 0m
2026-07-20 RPA3493 - Jul 20, 14:35 UTCJul 20, 15:55 UTC1h 20m
2026-07-20 RPA3498 CMH → EWR Jul 20, 12:20 UTCJul 20, 13:05 UTC45m
2026-07-20 RPA3524 EWR → MKE Jul 20, 09:40 UTCJul 20, 10:30 UTC50m
2026-07-20 RPA3692 ITH → EWR Jul 20, 02:15 UTCJul 20, 03:30 UTC1h 15m
2026-07-20 RPA3692 ITH → EWR Jul 20, 01:44 UTCJul 20, 03:26 UTC1h 42m
2026-07-19 RPA3415 - Jul 19, 20:45 UTCJul 19, 21:30 UTC45m
2026-07-19 RPA3704 EWR → DCA Jul 19, 16:05 UTCJul 19, 17:35 UTC1h 30m
2026-07-19 RPA3461 CVG → EWR Jul 19, 12:45 UTCJul 19, 14:00 UTC1h 15m
2026-07-19 RPA3461 CVG → EWR Jul 19, 12:52 UTCJul 19, 13:57 UTC1h 5m
2026-07-19 RPA3464 - Jul 19, 02:45 UTCJul 19, 03:45 UTC1h 0m
2026-07-18 RPA3659 - Jul 18, 22:00 UTCJul 18, 23:45 UTC1h 45m
2026-07-18 RPA3659 YOW → ORD Jul 18, 22:12 UTCJul 18, 23:35 UTC1h 23m

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 N743YX page for operator, model, and routing details .

Mode-S A9FFEB frequently asked

What is Mode-S code A9FFEB?
A9FFEB is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N743YX.
Where is Mode-S A9FFEB registered?
Mode-S code A9FFEB 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 A9FFEB broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 21:10 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A9FFEB, octal 52377753, decimal 11,141,099.
What flights does A9FFEB operate?
Mode-S A9FFEB has broadcast 20 distinct callsigns, including RPA3450, RPA3707, RPA3300, RPA3580, RPA3415.