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sensors Mode-S transponder

AA1635

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N749YX · EMBRAER ERJ-170-200 (long wing) · operated by UNITED AIRLINES INC

Hex
AA1635
Octal
52413065
Decimal
11,146,805
Country
US
Tail
N749YX
Type
E75L
No current signal · last broadcast Jul 26, 21:15 UTC
Flights observed
645
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:15 UTC

Last known position

Most recent position reported by Mode-S AA1635.

Country allocation

The ICAO 24-bit address AA1635 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 - 9 2026-07-03
RPA3661 - 8 2026-07-10
RPA3557 - 8 2026-07-13
RPA3447 - 8 2026-07-13
RPA3421 - 8 2026-07-15
RPA3711 - 7 2026-07-14
RPA3620 Republic Airlines 7 2026-07-23
RPA3477 - 7 2026-06-20
RPA3424 - 7 2026-06-22
RPA3681 - 6 2026-06-19
RPA3613 - 6 2026-06-27
RPA3496 Republic Airlines 6 2026-07-26
RPA3491 Republic Airlines 6 2026-07-24
RPA3486 Republic Airlines 6 2026-06-19
RPA3485 - 6 2026-07-16
RPA3702 - 5 2026-07-16
RPA3676 - 5 2026-07-13
RPA3634 Republic Airlines 5 2026-06-05
RPA3624 - 5 2026-07-07
RPA3623 Republic Airlines 5 2026-07-20

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 RPA3499 EWR → AVL Jul 26, 20:05 UTCJul 26, 21:15 UTC1h 10m
2026-07-26 RPA3690 SDF → ORD Jul 26, 16:40 UTCJul 26, 17:15 UTC35m
2026-07-26 RPA3690 SDF → ORD Jul 26, 16:28 UTCJul 26, 19:14 UTC2h 46m
2026-07-26 RPA3632 ORF → EWR Jul 26, 12:05 UTCJul 26, 14:05 UTC2h 0m
2026-07-26 RPA3496 YUL → IAD Jul 26, 00:02 UTCJul 26, 01:27 UTC1h 25m
2026-07-25 RPA3496 YUL → IAD Jul 25, 23:45 UTCJul 26, 01:15 UTC1h 30m
2026-07-25 RPA3542 YYZ → EWR Jul 25, 19:10 UTCJul 25, 21:10 UTC2h 0m
2026-07-25 RPA3581 RDU → EWR Jul 25, 16:30 UTCJul 25, 18:10 UTC1h 40m
2026-07-25 RPA3497 CHS → EWR Jul 25, 13:20 UTCJul 25, 14:10 UTC50m
2026-07-24 RPA3472 EWR → CLT Jul 24, 23:40 UTCJul 25, 01:15 UTC1h 35m
2026-07-24 RPA3456 IAD → IND Jul 24, 20:10 UTCJul 24, 21:30 UTC1h 20m
2026-07-24 RPA3537 EWR → BUF Jul 24, 17:22 UTCJul 24, 18:30 UTC1h 8m
2026-07-24 RPA3537 EWR → BUF Jul 24, 17:10 UTCJul 24, 18:35 UTC1h 25m
2026-07-24 RPA3451 MKE → EWR Jul 24, 13:10 UTCJul 24, 14:45 UTC1h 35m
2026-07-24 RPA3683 DCA → EWR Jul 24, 10:35 UTCJul 24, 12:15 UTC1h 40m
2026-07-24 RPA3491 BUF → EWR Jul 24, 00:15 UTCJul 24, 01:10 UTC55m
2026-07-23 RPA3478 EWR → ILM Jul 23, 22:05 UTCJul 23, 23:05 UTC1h 0m
2026-07-23 RPA3620 ORF → EWR Jul 23, 19:40 UTCJul 23, 20:40 UTC1h 0m
2026-07-23 RPA3685 YYZ → EWR Jul 23, 17:15 UTCJul 23, 18:00 UTC45m
2026-07-23 RPA3503 YHZ → EWR Jul 23, 14:40 UTCJul 23, 16:13 UTC1h 33m
2026-07-23 RPA3503 - Jul 23, 14:15 UTCJul 23, 16:15 UTC2h 0m
2026-07-23 RPA3428 CMH → EWR Jul 23, 01:25 UTCJul 23, 02:35 UTC1h 10m
2026-07-23 RPA3428 CMH → EWR Jul 23, 01:30 UTCJul 23, 02:52 UTC1h 22m
2026-07-22 RPA3654 EWR → ROC Jul 22, 22:10 UTCJul 22, 23:15 UTC1h 5m
2026-07-22 RPA3654 EWR → ROC Jul 22, 22:00 UTCJul 22, 23:18 UTC1h 18m
2026-07-22 RPA3603 EWR → YYZ Jul 22, 19:45 UTCJul 22, 20:40 UTC55m
2026-07-22 RPA3609 - Jul 22, 17:00 UTCJul 22, 18:40 UTC1h 40m
2026-07-22 RPA3697 - Jul 22, 13:55 UTCJul 22, 15:45 UTC1h 50m
2026-07-21 RPA3555 SAV → EWR Jul 21, 14:27 UTCJul 21, 17:53 UTC3h 26m
2026-07-20 RPA3623 EWR → ITH Jul 20, 19:55 UTCJul 20, 21:40 UTC1h 45m
2026-07-20 RPA3526 - Jul 20, 17:25 UTCJul 20, 18:35 UTC1h 10m
2026-07-19 RPA3678 GSO → EWR Jul 19, 21:45 UTCJul 19, 23:35 UTC1h 50m
2026-07-19 RPA3306 - Jul 19, 18:45 UTCJul 19, 20:35 UTC1h 50m
2026-07-19 RPA3540 - Jul 19, 03:50 UTCJul 19, 04:25 UTC35m
2026-07-19 RPA3491 - Jul 19, 00:55 UTCJul 19, 02:20 UTC1h 25m
2026-07-18 RPA3491 - Jul 18, 16:25 UTCJul 18, 18:15 UTC1h 50m
2026-07-18 RPA3459 IAD → YHZ Jul 18, 13:26 UTCJul 18, 15:18 UTC1h 52m
2026-07-18 RPA3459 - Jul 18, 13:40 UTCJul 18, 15:20 UTC1h 40m
2026-07-18 RPA3656 LGA → IAD Jul 18, 10:25 UTCJul 18, 11:15 UTC50m
2026-07-18 RPA3682 IND → EWR Jul 18, 03:10 UTCJul 18, 04:00 UTC50m
2026-07-17 RPA3628 - Jul 17, 23:10 UTCJul 18, 01:15 UTC2h 5m
2026-07-17 RPA3436 CLT → EWR Jul 17, 19:09 UTCJul 17, 21:15 UTC2h 5m
2026-07-17 RPA3436 CLT → EWR Jul 17, 19:10 UTCJul 17, 21:40 UTC2h 30m
2026-07-17 RPA3609 - Jul 17, 16:10 UTCJul 17, 18:00 UTC1h 50m
2026-07-17 RPA3697 EWR → MKE Jul 17, 13:00 UTCJul 17, 14:50 UTC1h 50m
2026-07-17 RPA3718 - Jul 17, 10:20 UTCJul 17, 11:39 UTC1h 20m
2026-07-16 RPA3580 EWR → GRR Jul 16, 23:59 UTCJul 17, 01:35 UTC1h 35m
2026-07-16 RPA3469 - Jul 16, 20:00 UTCJul 16, 21:30 UTC1h 30m
2026-07-16 RPA3702 ORD → IND Jul 16, 18:15 UTCJul 16, 18:50 UTC35m
2026-07-16 RPA3485 - Jul 16, 15:35 UTCJul 16, 16:40 UTC1h 5m

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 N749YX page for operator, model, and routing details .

Mode-S AA1635 frequently asked

What is Mode-S code AA1635?
AA1635 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N749YX.
Where is Mode-S AA1635 registered?
Mode-S code AA1635 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 AA1635 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 21:15 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AA1635, octal 52413065, decimal 11,146,805.
What flights does AA1635 operate?
Mode-S AA1635 has broadcast 20 distinct callsigns, including RPA3450, RPA3661, RPA3557, RPA3447, RPA3421.