Apparatus

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sensors Mode-S transponder

A2659A

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N2534U · BOEING 777-300ER · operated by UNITED AIRLINES INC

Hex
A2659A
Octal
50462632
Decimal
10,642,842
Country
US
Tail
N2534U
Type
B77W
No current signal · last broadcast 3h ago
Flights observed
213
Distinct callsigns
20
Country
US
Last broadcast
3h ago

Last known position

Most recent position reported by Mode-S A2659A.

Country allocation

The ICAO 24-bit address A2659A 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
UAL872 - 19 2026-06-24
UAL871 - 18 2026-06-22
UAL1175 - 12 2026-07-10
UAL838 - 11 2026-06-21
UAL837 United Airlines 11 2026-06-20
UAL988 - 8 2026-07-02
UAL189 - 8 2026-06-26
UAL857 United Airlines 7 2026-05-23
UAL989 - 6 2026-07-03
UAL877 - 6 2026-07-14
UAL41 - 6 2026-07-09
UAL200 - 6 2026-07-12
UAL190 - 6 2026-06-27
UAL951 United Airlines 5 2026-07-03
UAL950 - 5 2026-07-02
UAL862 - 5 2026-06-20
UAL810 - 5 2026-06-25
UAL809 - 5 2026-06-24
UAL435 - 5 2026-06-29
UAL43 - 5 2026-07-04

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 UAL877 - Jul 14, 07:40 UTCJul 14, 08:05 UTC25m
2026-07-12 UAL1346 - Jul 12, 12:40 UTCJul 12, 13:15 UTC35m
2026-07-12 UAL1346 HNL → SFO Jul 12, 08:49 UTCJul 12, 13:09 UTC4h 20m
2026-07-12 UAL200 - Jul 12, 03:50 UTCJul 12, 04:15 UTC25m
2026-07-11 UAL201 - Jul 11, 01:00 UTCJul 11, 01:10 UTC10m
2026-07-10 UAL1175 - Jul 10, 21:20 UTCJul 10, 21:35 UTC15m
2026-07-10 UAL1175 - Jul 10, 16:40 UTCJul 10, 17:10 UTC30m
2026-07-10 UAL1844 - Jul 10, 00:00 UTCJul 10, 05:35 UTC5h 35m
2026-07-09 UAL41 - Jul 9, 11:25 UTCJul 9, 19:45 UTC8h 20m
2026-07-09 UAL41 FCO → EWR Jul 9, 10:37 UTCJul 9, 19:47 UTC9h 10m
2026-07-09 UAL40 - Jul 9, 00:40 UTCJul 9, 08:30 UTC7h 50m
2026-07-08 UAL41 - Jul 8, 12:50 UTCJul 8, 21:25 UTC8h 35m
2026-07-07 UAL40 EWR → FCO Jul 7, 22:15 UTCJul 8, 05:55 UTC7h 40m
2026-07-07 UAL41 FCO → EWR Jul 7, 09:30 UTCJul 7, 18:10 UTC8h 40m
2026-07-06 UAL40 - Jul 6, 22:45 UTCJul 7, 00:25 UTC1h 40m
2026-07-06 UAL40 EWR → FCO Jul 6, 21:58 UTCJul 7, 06:16 UTC8h 18m
2026-07-06 UAL41 FCO → EWR Jul 6, 09:30 UTCJul 6, 18:25 UTC8h 55m
2026-07-06 UAL41 FCO → EWR Jul 6, 09:27 UTCJul 6, 18:19 UTC8h 52m
2026-07-05 UAL40 - Jul 5, 22:00 UTCJul 6, 05:05 UTC7h 5m
2026-07-04 UAL43 FRA → EWR Jul 4, 09:45 UTCJul 4, 17:40 UTC7h 55m
2026-07-03 UAL989 IAD → FRA Jul 3, 21:45 UTCJul 4, 04:45 UTC7h 0m
2026-07-03 UAL951 BRU → IAD Jul 3, 10:20 UTCJul 3, 18:15 UTC7h 55m
2026-07-03 UAL951 BRU → IAD Jul 3, 10:14 UTCJul 3, 18:09 UTC7h 55m
2026-07-02 UAL950 IAD → BRU Jul 2, 22:45 UTCJul 3, 05:30 UTC6h 45m
2026-07-02 UAL988 FRA → IAD Jul 2, 11:00 UTCJul 2, 19:25 UTC8h 25m
2026-07-02 UAL989 - Jul 2, 03:40 UTCJul 2, 05:20 UTC1h 40m
2026-07-01 UAL989 - Jul 1, 22:20 UTCJul 2, 00:15 UTC1h 55m
2026-07-01 UAL951 BRU → IAD Jul 1, 10:20 UTCJul 1, 10:30 UTC10m
2026-07-01 UAL951 BRU → IAD Jul 1, 10:19 UTCJul 1, 18:17 UTC7h 58m
2026-06-30 UAL950 IAD → BRU Jun 30, 22:20 UTCJul 1, 05:10 UTC6h 50m
2026-06-30 UAL950 IAD → BRU Jun 30, 22:13 UTCJul 1, 05:06 UTC6h 53m
2026-06-30 UAL988 - Jun 30, 10:50 UTCJun 30, 18:40 UTC7h 50m
2026-06-30 UAL42 - Jun 30, 00:20 UTCJun 30, 07:00 UTC6h 40m
2026-06-29 UAL435 SFO → EWR Jun 29, 15:39 UTCJun 29, 20:30 UTC4h 50m
2026-06-29 UAL1346 - Jun 29, 08:35 UTCJun 29, 13:00 UTC4h 25m
2026-06-29 UAL200 - Jun 29, 03:29 UTCJun 29, 03:54 UTC25m
2026-06-28 UAL201 - Jun 28, 00:59 UTCJun 28, 01:10 UTC10m
2026-06-27 UAL1175 - Jun 27, 16:49 UTCJun 27, 21:25 UTC4h 35m
2026-06-27 UAL190 - Jun 27, 01:59 UTCJun 27, 14:14 UTC12h 15m
2026-06-27 UAL190 MNL → SFO Jun 27, 01:01 UTCJun 27, 14:11 UTC13h 10m
2026-06-26 UAL189 - Jun 26, 08:40 UTCJun 26, 21:35 UTC12h 55m
2026-06-26 UAL189 SFO → MNL Jun 26, 08:38 UTCJun 26, 21:32 UTC12h 54m
2026-06-25 UAL810 MNL → SFO Jun 25, 14:44 UTCJun 26, 03:00 UTC12h 15m
2026-06-24 UAL809 SFO → MNL Jun 24, 22:55 UTCJun 25, 11:35 UTC12h 40m
2026-06-24 UAL872 - Jun 24, 12:44 UTCJun 24, 13:20 UTC35m
2026-06-24 UAL872 TPE → SFO Jun 24, 02:23 UTCJun 24, 13:19 UTC10h 56m
2026-06-24 UAL872 - Jun 24, 02:15 UTCJun 24, 02:34 UTC20m
2026-06-22 UAL871 SFO → TPE Jun 22, 22:08 UTCJun 23, 10:30 UTC12h 22m
2026-06-22 UAL871 - Jun 22, 22:10 UTCJun 23, 03:04 UTC4h 55m
2026-06-21 UAL838 - Jun 21, 08:25 UTCJun 21, 17:20 UTC8h 55m

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 N2534U page for operator, model, and routing details .

Mode-S A2659A frequently asked

What is Mode-S code A2659A?
A2659A is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N2534U.
Where is Mode-S A2659A registered?
Mode-S code A2659A 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 A2659A broadcasting right now?
No active broadcast right now. Last signal was 3h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A2659A, octal 50462632, decimal 10,642,842.
What flights does A2659A operate?
Mode-S A2659A has broadcast 20 distinct callsigns, including UAL872, UAL871, UAL1175, UAL838, UAL837.