Apparatus

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sensors Mode-S transponder

A12403

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N17272 · BOEING 737 MAX 7 · operated by UNITED AIRLINES INC

Hex
A12403
Octal
50222003
Decimal
10,560,515
Country
US
Tail
N17272
Type
B37M
Transponder active on ground
Flights observed
396
Distinct callsigns
20
Country
US
Last broadcast
37m ago

Last known position

Most recent position reported by Mode-S A12403.

Country allocation

The ICAO 24-bit address A12403 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
UAL1065 United Airlines 6 2026-04-17
UAL2264 United Airlines 5 2026-04-18
UAL1684 - 5 2026-06-16
UAL1533 - 5 2026-06-28
UAL2384 - 4 2026-06-30
UAL2215 United Airlines 4 2026-05-02
UAL2010 United Airlines 4 2026-06-16
UAL1917 United Airlines 4 2026-06-12
UAL1908 - 4 2026-06-28
UAL1579 United Airlines 4 2026-05-20
UAL1317 United Airlines 4 2026-07-06
UAL1299 - 4 2026-07-12
UAL1298 - 4 2026-07-11
UAL1271 United Airlines 4 2026-05-28
UAL1079 United Airlines 4 2026-06-09
UAL795 - 3 2026-07-12
UAL783 United Airlines 3 2026-05-15
UAL554 United Airlines 3 2026-06-09
UAL508 United Airlines 3 2026-04-24
UAL368 - 3 2026-06-19

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 UAL2307 - Jul 14, 12:10 UTCJul 14, 14:45 UTC2h 35m
2026-07-14 UAL1214 DEN → PHL Jul 14, 06:20 UTCJul 14, 09:35 UTC3h 15m
2026-07-14 UAL2436 SFO → DEN Jul 14, 02:20 UTCJul 14, 04:25 UTC2h 5m
2026-07-13 UAL2866 - Jul 13, 23:00 UTCJul 14, 01:05 UTC2h 5m
2026-07-13 UAL8244 SFO → SEA Jul 13, 19:30 UTCJul 13, 20:55 UTC1h 25m
2026-07-13 UAL369 - Jul 13, 12:05 UTCJul 13, 17:00 UTC4h 55m
2026-07-12 UAL2386 SFO → DCA Jul 12, 21:30 UTCJul 13, 02:15 UTC4h 45m
2026-07-12 UAL795 - Jul 12, 14:01 UTCJul 12, 18:55 UTC4h 55m
2026-07-12 UAL1965 - Jul 12, 07:25 UTCJul 12, 12:10 UTC4h 45m
2026-07-12 UAL1299 - Jul 12, 00:50 UTCJul 12, 05:40 UTC4h 50m
2026-07-11 UAL1298 - Jul 11, 17:55 UTCJul 11, 22:40 UTC4h 45m
2026-07-11 UAL1298 SFO → LIH Jul 11, 18:02 UTCJul 11, 23:04 UTC5h 2m
2026-07-11 UAL1597 - Jul 11, 11:20 UTCJul 11, 15:55 UTC4h 35m
2026-07-11 UAL1597 CMH → SFO Jul 11, 11:16 UTCJul 11, 15:48 UTC4h 32m
2026-07-11 UAL1939 SFO → CMH Jul 11, 04:48 UTCJul 11, 08:44 UTC3h 56m
2026-07-11 UAL1939 SFO → CMH Jul 11, 04:45 UTCJul 11, 08:50 UTC4h 5m
2026-07-11 UAL2657 - Jul 11, 02:00 UTCJul 11, 03:05 UTC1h 5m
2026-07-10 UAL1350 - Jul 10, 18:45 UTCJul 11, 00:50 UTC6h 5m
2026-07-10 UAL674 - Jul 10, 15:30 UTCJul 10, 17:05 UTC1h 35m
2026-07-10 UAL1108 - Jul 10, 12:50 UTCJul 10, 14:10 UTC1h 20m
2026-07-10 UAL1562 GUA → IAD Jul 10, 07:00 UTCJul 10, 10:40 UTC3h 40m
2026-07-10 UAL1523 IAD → GUA Jul 10, 01:35 UTCJul 10, 05:35 UTC4h 0m
2026-07-09 UAL2250 - Jul 9, 17:15 UTCJul 9, 20:20 UTC3h 5m
2026-07-09 UAL2250 SAT → IAD Jul 9, 17:14 UTCJul 9, 20:18 UTC3h 4m
2026-07-09 UAL1789 - Jul 9, 12:50 UTCJul 9, 15:40 UTC2h 50m
2026-07-09 UAL1789 - Jul 9, 10:10 UTCJul 9, 10:55 UTC45m
2026-07-09 UAL2382 IAD → RDU Jul 9, 03:20 UTCJul 9, 04:00 UTC40m
2026-07-08 UAL2677 - Jul 8, 23:50 UTCJul 9, 00:25 UTC35m
2026-07-08 UAL1784 LAS → EWR Jul 8, 17:10 UTCJul 8, 21:30 UTC4h 20m
2026-07-07 UAL1864 DEN → IAH Jul 7, 16:40 UTCJul 7, 21:10 UTC4h 30m
2026-07-06 UAL1317 EWR → IAH Jul 6, 23:10 UTCJul 7, 03:45 UTC4h 35m
2026-07-06 UAL1317 EWR → IAH Jul 6, 22:51 UTCJul 7, 03:43 UTC4h 52m
2026-07-06 UAL446 EWR → LAS Jul 6, 17:05 UTCJul 6, 21:40 UTC4h 35m
2026-07-06 UAL2396 IAD → EWR Jul 6, 14:00 UTCJul 6, 15:05 UTC1h 5m
2026-07-06 UAL1366 EWR → IAD Jul 6, 10:40 UTCJul 6, 11:30 UTC50m
2026-07-06 UAL1317 EWR → IAH Jul 6, 07:15 UTCJul 6, 08:00 UTC45m
2026-07-05 UAL1317 EWR → IAH Jul 5, 23:30 UTCJul 6, 04:10 UTC4h 40m
2026-07-05 UAL446 - Jul 5, 15:15 UTCJul 5, 19:50 UTC4h 35m
2026-07-05 UAL648 STL → EWR Jul 5, 11:20 UTCJul 5, 13:15 UTC1h 55m
2026-07-04 UAL442 EWR → STL Jul 4, 21:25 UTCJul 4, 23:40 UTC2h 15m
2026-07-04 UAL221 - Jul 4, 11:30 UTCJul 4, 18:45 UTC7h 15m
2026-07-04 UAL221 SCQ → EWR Jul 4, 11:09 UTCJul 4, 18:43 UTC7h 34m
2026-07-04 UAL222 EWR → SCQ Jul 4, 01:48 UTCJul 4, 09:01 UTC7h 13m
2026-07-04 UAL222 - Jul 4, 02:45 UTCJul 4, 03:35 UTC50m
2026-07-03 UAL231 - Jul 3, 13:30 UTCJul 3, 14:00 UTC30m
2026-07-03 UAL231 GLA → EWR Jul 3, 13:15 UTCJul 3, 20:34 UTC7h 19m
2026-07-03 UAL231 GLA → EWR Jul 3, 13:15 UTCJul 3, 20:37 UTC7h 22m
2026-07-03 UAL230 - Jul 3, 02:40 UTCJul 3, 03:55 UTC1h 15m
2026-07-03 UAL230 EWR → GLA Jul 3, 02:37 UTCJul 3, 09:14 UTC6h 37m
2026-07-02 UAL2252 - Jul 2, 19:35 UTCJul 2, 23:55 UTC4h 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 N17272 page for operator, model, and routing details .

Mode-S A12403 frequently asked

What is Mode-S code A12403?
A12403 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N17272.
Where is Mode-S A12403 registered?
Mode-S code A12403 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 A12403 broadcasting right now?
Mode-S A12403 is currently broadcasting from the ground.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A12403, octal 50222003, decimal 10,560,515.
What flights does A12403 operate?
Mode-S A12403 has broadcast 20 distinct callsigns, including UAL1065, UAL2264, UAL1684, UAL1533, UAL2384.