Apparatus

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sensors Mode-S transponder

AA4EE9

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N763YX · EMBRAER ERJ-170-200 (long wing) · operated by REPUBLIC AIRWAYS INC

Hex
AA4EE9
Octal
52447351
Decimal
11,161,321
Country
US
Tail
N763YX
Type
E75L
No current signal · last broadcast Jul 26, 22:15 UTC
Flights observed
570
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:15 UTC

Last known position

Most recent position reported by Mode-S AA4EE9.

Country allocation

The ICAO 24-bit address AA4EE9 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
RPA3717 Republic Airlines 9 2026-06-11
RPA3626 - 9 2026-07-05
RPA3651 Republic Airlines 8 2026-07-23
RPA3609 - 8 2026-07-19
RPA3477 - 8 2026-06-17
RPA3655 Republic Airlines 6 2026-07-24
RPA3591 - 6 2026-07-10
RPA3510 - 6 2026-07-16
RPA3449 - 6 2026-06-16
RPA3439 Republic Airlines 6 2026-06-13
RPA3718 Republic Airlines 5 2026-05-08
RPA3705 - 5 2026-06-14
RPA3679 Republic Airlines 5 2026-06-02
RPA3658 Republic Airlines 5 2026-07-24
RPA3634 - 5 2026-07-16
RPA3604 Republic Airlines 5 2026-06-11
RPA3576 - 5 2026-07-06
RPA3554 Republic Airlines 5 2026-06-02
RPA3506 Republic Airlines 5 2026-06-11
RPA3505 - 5 2026-07-07

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 RPA3710 ORF → EWR Jul 26, 21:10 UTCJul 26, 22:15 UTC1h 5m
2026-07-26 RPA3492 EWR → CLT Jul 26, 18:50 UTCJul 26, 20:00 UTC1h 10m
2026-07-26 RPA3409 BOS → EWR Jul 26, 13:15 UTCJul 26, 14:15 UTC1h 0m
2026-07-26 RPA3409 BOS → EWR Jul 26, 13:16 UTCJul 26, 14:48 UTC1h 32m
2026-07-25 RPA3586 EWR → GSO Jul 25, 22:28 UTCJul 25, 23:34 UTC1h 6m
2026-07-25 RPA3586 EWR → GSO Jul 25, 22:10 UTCJul 25, 23:40 UTC1h 30m
2026-07-25 RPA3713 MKE → EWR Jul 25, 19:10 UTCJul 25, 20:20 UTC1h 10m
2026-07-25 RPA3508 ROC → EWR Jul 25, 16:20 UTCJul 25, 17:30 UTC1h 10m
2026-07-25 RPA3560 CLT → EWR Jul 25, 13:20 UTCJul 25, 14:20 UTC1h 0m
2026-07-25 RPA3464 BUF → EWR Jul 25, 02:40 UTCJul 25, 03:35 UTC55m
2026-07-24 RPA3597 SRQ → EWR Jul 24, 22:50 UTCJul 25, 00:55 UTC2h 5m
2026-07-24 RPA3658 GRR → EWR Jul 24, 19:35 UTCJul 24, 21:25 UTC1h 50m
2026-07-24 RPA3617 EWR → PVD Jul 24, 14:30 UTCJul 24, 15:40 UTC1h 10m
2026-07-24 RPA3553 SAT → EWR Jul 24, 11:50 UTCJul 24, 12:55 UTC1h 5m
2026-07-24 RPA3655 EWR → SDF Jul 24, 00:35 UTCJul 24, 01:45 UTC1h 10m
2026-07-24 RPA3655 EWR → SDF Jul 24, 00:40 UTCJul 24, 01:43 UTC1h 3m
2026-07-23 RPA3651 EWR → CVG Jul 23, 22:05 UTCJul 23, 23:10 UTC1h 5m
2026-07-23 RPA3637 ROC → EWR Jul 23, 18:50 UTCJul 23, 19:55 UTC1h 5m
2026-07-23 RPA3400 EWR → TVC Jul 23, 16:45 UTCJul 23, 17:45 UTC1h 0m
2026-07-23 RPA3409 BOS → EWR Jul 23, 13:35 UTCJul 23, 14:40 UTC1h 5m
2026-07-22 RPA3586 EWR → GSO Jul 22, 22:45 UTCJul 23, 00:15 UTC1h 30m
2026-07-22 RPA3611 MSY → ORD Jul 22, 19:45 UTCJul 22, 21:00 UTC1h 15m
2026-07-22 RPA3495 EWR → YYZ Jul 22, 17:10 UTCJul 22, 18:15 UTC1h 5m
2026-07-22 RPA3402 AVL → EWR Jul 22, 14:20 UTCJul 22, 15:40 UTC1h 20m
2026-07-22 RPA3410 ORD → MSN Jul 22, 12:30 UTCJul 22, 13:20 UTC50m
2026-07-21 RPA3474 EWR → MYR Jul 21, 11:15 UTCJul 21, 12:35 UTC1h 20m
2026-07-21 RPA3408 DCA → EWR Jul 21, 01:55 UTCJul 21, 02:55 UTC1h 0m
2026-07-20 RPA3716 - Jul 20, 23:45 UTCJul 21, 00:35 UTC50m
2026-07-20 RPA3607 EWR → MSN Jul 20, 20:55 UTCJul 20, 21:50 UTC55m
2026-07-20 RPA3694 ORF → IAD Jul 20, 18:00 UTCJul 20, 19:45 UTC1h 45m
2026-07-20 RPA3694 ORF → IAD Jul 20, 17:46 UTCJul 20, 19:37 UTC1h 51m
2026-07-20 RPA3421 CLT → EWR Jul 20, 14:45 UTCJul 20, 16:25 UTC1h 40m
2026-07-20 RPA3719 IND → EWR Jul 20, 00:55 UTCJul 20, 01:45 UTC50m
2026-07-20 RPA3719 IND → EWR Jul 20, 00:45 UTCJul 20, 01:42 UTC57m
2026-07-19 RPA3609 MKE → EWR Jul 19, 22:58 UTCJul 19, 23:38 UTC40m
2026-07-19 RPA3609 EWR → BOS Jul 19, 22:50 UTCJul 19, 23:40 UTC50m
2026-07-18 RPA3504 EWR → EYW Jul 18, 14:42 UTCJul 18, 18:38 UTC3h 56m
2026-07-18 RPA3706 - Jul 18, 12:10 UTCJul 18, 13:35 UTC1h 25m
2026-07-18 RPA3592 BNA → EWR Jul 18, 03:35 UTCJul 18, 04:40 UTC1h 5m
2026-07-18 RPA3460 YYZ → EWR Jul 18, 00:53 UTCJul 18, 02:06 UTC1h 13m
2026-07-18 RPA3460 YYZ → EWR Jul 18, 01:05 UTCJul 18, 02:09 UTC1h 5m
2026-07-17 RPA3531 - Jul 17, 21:34 UTCJul 17, 22:45 UTC1h 10m
2026-07-17 RPA3485 - Jul 17, 18:19 UTCJul 17, 19:20 UTC1h 0m
2026-07-17 RPA3305 - Jul 17, 16:55 UTCJul 17, 17:20 UTC25m
2026-07-16 RPA3455 CMH → EWR Jul 16, 23:40 UTCJul 17, 00:14 UTC35m
2026-07-16 RPA3440 BNA → ORD Jul 16, 20:19 UTCJul 16, 22:00 UTC1h 40m
2026-07-16 RPA3634 - Jul 16, 18:00 UTCJul 16, 19:05 UTC1h 5m
2026-07-16 RPA3634 ORD → BNA Jul 16, 18:00 UTCJul 16, 18:54 UTC54m
2026-07-16 RPA3617 - Jul 16, 14:35 UTCJul 16, 15:49 UTC1h 15m
2026-07-16 RPA3553 EWR → YYZ Jul 16, 11:45 UTCJul 16, 13:00 UTC1h 15m

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 N763YX page for operator, model, and routing details .

Mode-S AA4EE9 frequently asked

What is Mode-S code AA4EE9?
AA4EE9 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N763YX.
Where is Mode-S AA4EE9 registered?
Mode-S code AA4EE9 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 AA4EE9 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 22:15 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AA4EE9, octal 52447351, decimal 11,161,321.
What flights does AA4EE9 operate?
Mode-S AA4EE9 has broadcast 20 distinct callsigns, including RPA3717, RPA3626, RPA3651, RPA3609, RPA3477.