sensors Mode-S transponder

A12B2B

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N17452 · operated by UNITED AIRLINES INC

Hex
A12B2B
Octal
50225453
Decimal
10,562,347
Country
US
Tail
N17452
Broadcasting now · callsign UAL2371 · 33,000 ft
Flights observed
316
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:45 UTC

Current position

A12B2B is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A12B2B 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
UAL668 United Airlines 6 2026-06-05
UAL702 - 4 2026-07-11
UAL552 United Airlines 4 2026-07-22
UAL2029 United Airlines 4 2026-07-22
UAL1798 - 4 2026-07-09
UAL1349 - 4 2026-07-17
UAL2495 - 3 2026-07-15
UAL2412 United Airlines 3 2026-07-25
UAL2372 United Airlines 3 2026-05-26
UAL2363 United Airlines 3 2026-07-22
UAL2192 United Airlines 3 2026-05-11
UAL1571 - 3 2026-07-15
UAL1556 United Airlines 3 2026-06-05
UAL1480 - 3 2026-07-14
UAL1213 United Airlines 3 2026-07-24
UAL8111 United Airlines 2 2026-06-07
UAL743 - 2 2026-07-15
UAL694 - 2 2026-07-12
UAL693 - 2 2026-07-13
UAL681 - 2 2026-07-14

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL8110 YYZ → ATL Jul 26, 22:30 UTCJul 26, 22:45 UTC15m
2026-07-25 UAL2368 SFO → DEN Jul 25, 18:10 UTCJul 25, 19:50 UTC1h 40m
2026-07-25 UAL2412 DEN → MSP Jul 25, 13:00 UTCJul 25, 16:15 UTC3h 15m
2026-07-25 UAL2412 DEN → MSP Jul 25, 12:43 UTCJul 25, 16:20 UTC3h 37m
2026-07-25 UAL1605 LAX → BWI Jul 25, 06:45 UTCJul 25, 11:25 UTC4h 40m
2026-07-24 UAL1213 EWR → ATL Jul 24, 23:45 UTCJul 25, 04:15 UTC4h 30m
2026-07-24 UAL1621 LAX → MCO Jul 24, 17:35 UTCJul 24, 22:15 UTC4h 40m
2026-07-24 UAL325 DEN → BOS Jul 24, 11:15 UTCJul 24, 16:05 UTC4h 50m
2026-07-24 UAL1784 STT → EWR Jul 24, 02:40 UTCJul 24, 03:25 UTC45m
2026-07-23 UAL2691 PWM → EWR Jul 23, 23:20 UTCJul 24, 00:55 UTC1h 35m
2026-07-23 UAL2691 PWM → EWR Jul 23, 22:30 UTCJul 23, 23:15 UTC45m
2026-07-23 UAL1511 EWR → MIA Jul 23, 17:50 UTCJul 23, 20:55 UTC3h 5m
2026-07-23 UAL408 - Jul 23, 13:15 UTCJul 23, 16:00 UTC2h 45m
2026-07-22 UAL2029 ORD → RIC Jul 22, 15:50 UTCJul 22, 21:00 UTC5h 10m
2026-07-22 UAL2363 PHL → ORD Jul 22, 13:15 UTCJul 22, 14:10 UTC55m
2026-07-22 UAL552 SFO → LAX Jul 22, 04:25 UTCJul 22, 05:25 UTC1h 0m
2026-07-21 UAL2462 YVR → SFO Jul 21, 21:45 UTCJul 22, 02:45 UTC5h 0m
2026-07-21 UAL608 IAD → EWR Jul 21, 15:25 UTCJul 21, 19:55 UTC4h 30m
2026-07-21 UAL2075 IAD → BDL Jul 21, 00:55 UTCJul 21, 05:55 UTC5h 0m
2026-07-21 UAL2075 IAD → BDL Jul 21, 01:03 UTCJul 21, 05:53 UTC4h 50m
2026-07-20 UAL2667 ORD → PHL Jul 20, 18:05 UTCJul 20, 22:40 UTC4h 35m
2026-07-20 UAL325 DEN → BOS Jul 20, 11:10 UTCJul 20, 15:40 UTC4h 30m
2026-07-19 UAL2388 - Jul 19, 21:55 UTCJul 20, 01:10 UTC3h 15m
2026-07-19 UAL2498 - Jul 19, 16:50 UTCJul 19, 20:15 UTC3h 25m
2026-07-19 UAL1301 DEN → SFO Jul 19, 12:20 UTCJul 19, 14:25 UTC2h 5m
2026-07-19 UAL2852 - Jul 19, 01:40 UTCJul 19, 05:05 UTC3h 25m
2026-07-18 UAL2740 - Jul 18, 22:15 UTCJul 19, 00:15 UTC2h 0m
2026-07-18 UAL1711 - Jul 18, 17:50 UTCJul 18, 20:30 UTC2h 40m
2026-07-18 UAL574 - Jul 18, 13:25 UTCJul 18, 16:25 UTC3h 0m
2026-07-18 UAL1503 ORD → BOS Jul 18, 00:35 UTCJul 18, 04:00 UTC3h 26m
2026-07-17 UAL1660 ANC → EWR Jul 17, 19:15 UTCJul 17, 22:55 UTC3h 40m
2026-07-17 UAL1349 PIT → LAX Jul 17, 14:05 UTCJul 17, 16:03 UTC1h 58m
2026-07-17 UAL1349 - Jul 17, 14:04 UTCJul 17, 14:44 UTC40m
2026-07-17 UAL2210 - Jul 17, 06:29 UTCJul 17, 11:39 UTC5h 10m
2026-07-16 UAL1213 - Jul 16, 23:49 UTCJul 17, 04:20 UTC4h 30m
2026-07-16 UAL1621 - Jul 16, 17:35 UTCJul 16, 22:15 UTC4h 40m
2026-07-16 UAL2113 - Jul 16, 11:20 UTCJul 16, 15:49 UTC4h 30m
2026-07-15 UAL1571 - Jul 15, 22:25 UTCJul 15, 22:45 UTC20m
2026-07-15 UAL1571 IAH → MCO Jul 15, 22:30 UTCJul 16, 00:15 UTC1h 45m
2026-07-15 UAL743 BWI → IAH Jul 15, 17:25 UTCJul 15, 19:39 UTC2h 14m
2026-07-15 UAL743 - Jul 15, 17:00 UTCJul 15, 19:40 UTC2h 40m
2026-07-15 UAL604 - Jul 15, 13:05 UTCJul 15, 15:45 UTC2h 40m
2026-07-15 UAL2495 - Jul 15, 06:15 UTCJul 15, 10:20 UTC4h 5m
2026-07-15 UAL1543 - Jul 15, 03:15 UTCJul 15, 03:40 UTC25m
2026-07-15 UAL1543 - Jul 15, 00:10 UTCJul 15, 01:00 UTC50m
2026-07-14 UAL681 - Jul 14, 19:10 UTCJul 14, 21:25 UTC2h 15m
2026-07-14 UAL681 NAS → EWR Jul 14, 18:52 UTCJul 14, 21:18 UTC2h 26m
2026-07-14 UAL1480 - Jul 14, 14:45 UTCJul 14, 16:30 UTC1h 45m
2026-07-14 UAL1480 EWR → NAS Jul 14, 14:38 UTCJul 14, 16:45 UTC2h 7m
2026-07-14 UAL1480 - Jul 14, 14:30 UTCJul 14, 14:40 UTC10m

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 N17452 page for operator, model, and routing details .

Mode-S A12B2B frequently asked

What is Mode-S code A12B2B?
A12B2B is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N17452.
Where is Mode-S A12B2B registered?
Mode-S code A12B2B 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 A12B2B broadcasting right now?
Yes. Mode-S A12B2B is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A12B2B, octal 50225453, decimal 10,562,347.
What flights does A12B2B operate?
Mode-S A12B2B has broadcast 20 distinct callsigns, including UAL668, UAL702, UAL552, UAL2029, UAL1798.