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
Broadcasting now · callsign UAL1847 · 32,000 ft
Flights observed
441
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:00 UTC

Current position

A12403 is currently broadcasting. Map zoomed to live position.

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
UAL776 United Airlines 5 2026-07-25
UAL765 United Airlines 5 2026-07-25
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
UAL1756 - 4 2026-07-24
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

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL1295 LAX → LIH Jul 26, 15:55 UTCJul 26, 21:00 UTC5h 5m
2026-07-26 UAL627 EWR → SAV Jul 26, 04:55 UTCJul 26, 05:35 UTC40m
2026-07-25 UAL765 EWR → DFW Jul 25, 18:20 UTCJul 25, 18:50 UTC30m
2026-07-25 UAL776 ORD → SJC Jul 25, 11:30 UTCJul 25, 15:45 UTC4h 15m
2026-07-25 UAL2641 SFO → SAN Jul 25, 06:05 UTCJul 25, 10:00 UTC3h 55m
2026-07-24 UAL418 SAN → SFO Jul 24, 23:18 UTCJul 25, 03:54 UTC4h 36m
2026-07-24 UAL417 LAX → OGG Jul 24, 21:15 UTCJul 24, 21:25 UTC10m
2026-07-24 UAL417 LAX → OGG Jul 24, 16:30 UTCJul 24, 16:55 UTC25m
2026-07-24 UAL1756 - Jul 24, 13:25 UTCJul 24, 14:05 UTC40m
2026-07-24 UAL374 EWR → PBI Jul 24, 02:15 UTCJul 24, 02:45 UTC30m
2026-07-23 UAL797 DEN → ICT Jul 23, 18:55 UTCJul 24, 00:15 UTC5h 20m
2026-07-23 UAL627 EWR → SAV Jul 23, 04:55 UTCJul 23, 05:35 UTC40m
2026-07-22 UAL765 EWR → DFW Jul 22, 23:35 UTCJul 22, 23:45 UTC10m
2026-07-22 UAL765 EWR → DFW Jul 22, 18:35 UTCJul 22, 19:05 UTC30m
2026-07-22 UAL765 EWR → DFW Jul 22, 18:34 UTCJul 22, 23:51 UTC5h 17m
2026-07-21 UAL1296 EWR → TPA Jul 21, 23:25 UTCJul 21, 23:40 UTC15m
2026-07-21 UAL1296 EWR → TPA Jul 21, 23:12 UTCJul 22, 04:10 UTC4h 58m
2026-07-21 UAL1295 LAX → LIH Jul 21, 16:05 UTCJul 21, 21:30 UTC5h 25m
2026-07-21 UAL1756 - Jul 21, 13:15 UTCJul 21, 13:50 UTC35m
2026-07-21 UAL374 EWR → PBI Jul 21, 01:50 UTCJul 21, 02:25 UTC35m
2026-07-20 UAL1286 AUS → LAX Jul 20, 18:20 UTCJul 21, 00:15 UTC5h 55m
2026-07-20 UAL776 ORD → SJC Jul 20, 12:00 UTCJul 20, 15:55 UTC3h 55m
2026-07-20 UAL776 ORD → SJC Jul 20, 11:35 UTCJul 20, 11:55 UTC20m
2026-07-20 UAL2641 - Jul 20, 05:50 UTCJul 20, 09:55 UTC4h 5m
2026-07-19 UAL1993 IAH → LGA Jul 19, 22:50 UTCJul 20, 03:25 UTC4h 35m
2026-07-19 UAL1993 IAH → LGA Jul 19, 22:18 UTCJul 20, 03:20 UTC5h 2m
2026-07-19 UAL775 - Jul 19, 15:25 UTCJul 19, 18:45 UTC3h 20m
2026-07-19 UAL775 IAD → EWR Jul 19, 15:37 UTCJul 19, 20:29 UTC4h 52m
2026-07-18 UAL605 SFO → PDX Jul 18, 23:10 UTCJul 19, 04:40 UTC5h 30m
2026-07-18 UAL2035 LAX → SFO Jul 18, 16:15 UTCJul 18, 21:15 UTC5h 0m
2026-07-18 UAL1612 - Jul 18, 08:35 UTCJul 18, 13:25 UTC4h 50m
2026-07-18 UAL1104 SJC → DEN Jul 18, 00:35 UTCJul 18, 01:05 UTC30m
2026-07-18 UAL1104 SJC → DEN Jul 18, 00:31 UTCJul 18, 06:06 UTC5h 35m
2026-07-17 UAL2146 LAX → DEN Jul 17, 19:35 UTCJul 17, 22:00 UTC2h 25m
2026-07-17 UAL1914 IAD → YVR Jul 17, 13:10 UTCJul 17, 18:15 UTC5h 5m
2026-07-17 UAL1562 GUA → IAD Jul 17, 06:05 UTCJul 17, 09:50 UTC3h 45m
2026-07-16 UAL1523 IAD → GUA Jul 16, 23:49 UTCJul 17, 03:25 UTC3h 35m
2026-07-16 UAL1567 - Jul 16, 15:00 UTCJul 16, 18:55 UTC3h 55m
2026-07-15 UAL1566 - Jul 15, 21:55 UTCJul 16, 02:00 UTC4h 5m
2026-07-15 UAL2344 AUS → IAD Jul 15, 17:17 UTCJul 15, 19:48 UTC2h 31m
2026-07-15 UAL2344 AUS → IAD Jul 15, 17:05 UTCJul 15, 19:50 UTC2h 45m
2026-07-15 UAL637 IAD → AUS Jul 15, 12:50 UTCJul 15, 15:35 UTC2h 45m
2026-07-15 UAL572 ANC → IAD Jul 15, 04:38 UTCJul 15, 10:34 UTC5h 56m
2026-07-15 UAL572 - Jul 15, 04:35 UTCJul 15, 08:30 UTC3h 55m
2026-07-14 UAL280 DEN → ANC Jul 14, 18:00 UTCJul 14, 23:10 UTC5h 9m
2026-07-14 UAL2307 PHL → DEN Jul 14, 12:10 UTCJul 14, 15:15 UTC3h 5m
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

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?
Yes. Mode-S A12403 is currently airborne.
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, UAL776, UAL765, UAL2264, UAL1684.