Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A2B810

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N27421 · BOEING 737-900 · operated by UNITED AIRLINES INC

Hex
A2B810
Octal
50534020
Decimal
10,663,952
Country
US
Tail
N27421
Type
B739
Broadcasting now · callsign UAL2433 · 34,000 ft
Flights observed
359
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Current position

A2B810 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A2B810 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
UAL1417 - 5 2026-07-01
UAL677 - 4 2026-06-19
UAL457 - 4 2026-06-20
UAL2659 United Airlines 4 2026-04-30
UAL1715 United Airlines 4 2026-05-02
UAL1458 United Airlines 4 2026-05-17
UAL644 United Airlines 3 2026-06-11
UAL587 United Airlines 3 2026-05-17
UAL519 United Airlines 3 2026-04-27
UAL357 - 3 2026-07-13
UAL2776 United Airlines 3 2026-06-09
UAL2674 United Airlines 3 2026-04-17
UAL2631 United Airlines 3 2026-04-30
UAL2370 United Airlines 3 2026-05-17
UAL2344 - 3 2026-07-09
UAL2158 United Airlines 3 2026-05-01
UAL1859 United Airlines 3 2026-05-24
UAL1811 United Airlines 3 2026-05-19
UAL1790 United Airlines 3 2026-04-25
UAL1701 United Airlines 3 2026-06-13

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 UAL2433 - Jul 14, 01:00 UTCJul 14, 02:00 UTC1h 0m
2026-07-13 UAL2466 - Jul 13, 21:35 UTCJul 13, 23:35 UTC2h 0m
2026-07-13 UAL1401 - Jul 13, 19:20 UTCJul 13, 19:30 UTC10m
2026-07-13 UAL1401 - Jul 13, 17:30 UTCJul 13, 19:30 UTC2h 0m
2026-07-13 UAL1401 ORD → PWM Jul 13, 17:25 UTCJul 13, 19:05 UTC1h 40m
2026-07-13 UAL2471 IAD → DFW Jul 13, 13:00 UTCJul 13, 15:30 UTC2h 30m
2026-07-13 UAL357 SFO → IAD Jul 13, 05:01 UTCJul 13, 09:45 UTC4h 45m
2026-07-13 UAL1302 - Jul 13, 02:05 UTCJul 13, 03:05 UTC1h 0m
2026-07-12 UAL1281 DEN → SAN Jul 12, 22:10 UTCJul 13, 00:05 UTC1h 55m
2026-07-12 UAL1150 ORD → DEN Jul 12, 18:35 UTCJul 12, 20:30 UTC1h 55m
2026-07-12 UAL2430 - Jul 12, 14:20 UTCJul 12, 16:15 UTC1h 55m
2026-07-12 UAL2666 ORD → DEN Jul 12, 10:25 UTCJul 12, 12:20 UTC1h 55m
2026-07-11 UAL2487 - Jul 11, 21:45 UTCJul 12, 01:30 UTC3h 45m
2026-07-11 UAL1044 - Jul 11, 16:00 UTCJul 11, 19:30 UTC3h 30m
2026-07-11 UAL567 MSP → ORD Jul 11, 12:52 UTCJul 11, 13:29 UTC37m
2026-07-11 UAL567 MSP → ORD Jul 11, 12:45 UTCJul 11, 13:40 UTC55m
2026-07-11 UAL1131 ORD → MSP Jul 11, 03:30 UTCJul 11, 04:25 UTC55m
2026-07-10 UAL1686 - Jul 10, 22:00 UTCJul 11, 01:20 UTC3h 20m
2026-07-10 UAL370 EWR → PHX Jul 10, 15:35 UTCJul 10, 20:10 UTC4h 35m
2026-07-10 UAL2603 - Jul 10, 11:15 UTCJul 10, 13:45 UTC2h 30m
2026-07-10 UAL1379 IAD → FLL Jul 10, 00:09 UTCJul 10, 03:00 UTC2h 51m
2026-07-10 UAL1379 IAD → FLL Jul 10, 00:55 UTCJul 10, 03:00 UTC2h 5m
2026-07-09 UAL2344 - Jul 9, 20:40 UTCJul 9, 20:50 UTC10m
2026-07-09 UAL2344 AUS → IAD Jul 9, 17:15 UTCJul 9, 20:50 UTC3h 35m
2026-07-09 UAL2344 AUS → IAD Jul 9, 17:19 UTCJul 9, 20:23 UTC3h 4m
2026-07-09 UAL637 - Jul 9, 12:40 UTCJul 9, 15:30 UTC2h 50m
2026-07-08 UAL1820 - Jul 8, 22:45 UTCJul 8, 23:55 UTC1h 10m
2026-07-08 UAL1817 - Jul 8, 17:00 UTCJul 8, 18:00 UTC1h 0m
2026-07-08 UAL1817 IAD → PLS Jul 8, 16:55 UTCJul 8, 19:43 UTC2h 48m
2026-07-08 UAL2022 - Jul 8, 13:55 UTCJul 8, 14:55 UTC1h 0m
2026-07-08 UAL2022 - Jul 8, 11:30 UTCJul 8, 11:45 UTC15m
2026-07-08 UAL2025 - Jul 8, 01:50 UTCJul 8, 02:10 UTC20m
2026-07-07 UAL2025 - Jul 7, 22:45 UTCJul 7, 23:45 UTC1h 0m
2026-07-07 UAL1576 TPA → IAD Jul 7, 18:45 UTCJul 7, 20:35 UTC1h 50m
2026-07-07 UAL1576 EWR → TPA Jul 7, 13:25 UTCJul 7, 16:15 UTC2h 50m
2026-07-07 UAL2147 IAD → EWR Jul 7, 10:45 UTCJul 7, 11:25 UTC40m
2026-07-06 UAL264 - Jul 6, 20:45 UTCJul 7, 01:15 UTC4h 30m
2026-07-06 UAL326 IAD → SEA Jul 6, 05:15 UTCJul 6, 10:15 UTC5h 0m
2026-07-05 UAL2250 - Jul 5, 17:05 UTCJul 5, 20:05 UTC3h 0m
2026-07-05 UAL1789 - Jul 5, 12:40 UTCJul 5, 15:35 UTC2h 55m
2026-07-05 UAL357 - Jul 5, 04:50 UTCJul 5, 09:35 UTC4h 45m
2026-07-05 UAL357 SFO → IAD Jul 5, 04:55 UTCJul 5, 09:30 UTC4h 35m
2026-07-04 UAL1159 CUN → SFO Jul 4, 20:59 UTCJul 5, 02:09 UTC5h 10m
2026-07-04 UAL1159 CUN → SFO Jul 4, 20:59 UTCJul 5, 02:10 UTC5h 11m
2026-07-04 UAL2604 - Jul 4, 14:10 UTCJul 4, 18:55 UTC4h 45m
2026-07-04 UAL367 IAD → SFO Jul 4, 03:00 UTCJul 4, 08:10 UTC5h 10m
2026-07-03 UAL444 - Jul 3, 20:35 UTCJul 4, 01:05 UTC4h 30m
2026-07-03 UAL8221 YVR → PDX Jul 3, 17:55 UTCJul 3, 19:05 UTC1h 10m
2026-07-03 UAL2194 MSY → SFO Jul 3, 02:25 UTCJul 3, 06:20 UTC3h 55m
2026-07-02 UAL782 SAT → EWR Jul 2, 20:00 UTCJul 2, 22:30 UTC2h 30m

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 N27421 page for operator, model, and routing details .

Mode-S A2B810 frequently asked

What is Mode-S code A2B810?
A2B810 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N27421.
Where is Mode-S A2B810 registered?
Mode-S code A2B810 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 A2B810 broadcasting right now?
Yes. Mode-S A2B810 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A2B810, octal 50534020, decimal 10,663,952.
What flights does A2B810 operate?
Mode-S A2B810 has broadcast 20 distinct callsigns, including UAL1417, UAL677, UAL457, UAL2659, UAL1715.