Apparatus

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sensors Mode-S transponder

A290D0

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N2644U · BOEING 777-300ER · operated by UNITED AIRLINES INC

Hex
A290D0
Octal
50510320
Decimal
10,653,904
Country
US
Tail
N2644U
Type
B77W
No current signal · last broadcast Jul 26, 20:50 UTC
Flights observed
171
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 20:50 UTC

Last known position

Most recent position reported by Mode-S A290D0.

Country allocation

The ICAO 24-bit address A290D0 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
UAL810 - 12 2026-07-09
UAL809 - 11 2026-07-08
UAL871 - 10 2026-07-16
UAL872 - 9 2026-07-17
UAL862 - 8 2026-07-11
UAL190 United Airlines 8 2026-07-25
UAL869 - 7 2026-07-06
UAL78 - 7 2026-07-12
UAL1175 - 7 2026-07-17
UAL878 - 6 2026-07-06
UAL877 United Airlines 6 2026-07-26
UAL857 United Airlines 5 2026-05-21
UAL837 - 5 2026-07-11
UAL435 - 5 2026-07-19
UAL189 United Airlines 5 2026-07-24
UAL950 United Airlines 4 2026-07-21
UAL838 - 4 2026-07-15
UAL201 United Airlines 4 2026-07-18
UAL200 - 4 2026-07-19
UAL951 United Airlines 3 2026-07-22

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL877 SFO → HKG Jul 26, 07:25 UTCJul 26, 20:45 UTC13h 20m
2026-07-25 UAL190 IAH → MIA Jul 25, 08:30 UTCJul 25, 21:00 UTC12h 30m
2026-07-25 UAL190 IAH → MIA Jul 25, 07:46 UTCJul 25, 20:55 UTC13h 9m
2026-07-24 UAL189 CLE → PHX Jul 24, 16:45 UTCJul 25, 05:15 UTC12h 30m
2026-07-23 UAL1844 EWR → MIA Jul 23, 23:00 UTCJul 24, 05:05 UTC6h 5m
2026-07-23 UAL43 OGG → EWR Jul 23, 10:00 UTCJul 23, 18:05 UTC8h 5m
2026-07-22 UAL989 IAD → FRA Jul 22, 22:23 UTCJul 23, 05:34 UTC7h 11m
2026-07-22 UAL989 IAD → FRA Jul 22, 22:30 UTCJul 23, 05:45 UTC7h 15m
2026-07-22 UAL951 BRU → IAD Jul 22, 11:10 UTCJul 22, 18:00 UTC6h 50m
2026-07-22 UAL951 BRU → IAD Jul 22, 10:14 UTCJul 22, 17:58 UTC7h 44m
2026-07-21 UAL950 IAD → BRU Jul 21, 23:05 UTCJul 22, 05:25 UTC6h 20m
2026-07-21 UAL950 IAD → BRU Jul 21, 22:18 UTCJul 22, 06:19 UTC8h 1m
2026-07-21 UAL951 BRU → IAD Jul 21, 10:25 UTCJul 21, 18:00 UTC7h 35m
2026-07-20 UAL950 IAD → BRU Jul 20, 23:03 UTCJul 21, 05:46 UTC6h 43m
2026-07-20 UAL950 IAD → BRU Jul 20, 23:00 UTCJul 21, 05:50 UTC6h 50m
2026-07-20 UAL988 - Jul 20, 11:00 UTCJul 20, 18:55 UTC7h 55m
2026-07-20 UAL42 OGG → EWR Jul 20, 00:30 UTCJul 20, 07:25 UTC6h 55m
2026-07-19 UAL435 - Jul 19, 16:15 UTCJul 19, 21:00 UTC4h 45m
2026-07-19 UAL435 SFO → EWR Jul 19, 15:54 UTCJul 19, 20:55 UTC5h 1m
2026-07-19 UAL1346 - Jul 19, 08:30 UTCJul 19, 12:50 UTC4h 20m
2026-07-19 UAL200 - Jul 19, 03:40 UTCJul 19, 04:00 UTC20m
2026-07-18 UAL201 HNL → GUM Jul 18, 00:39 UTCJul 18, 00:50 UTC10m
2026-07-17 UAL1175 - Jul 17, 21:15 UTCJul 17, 21:30 UTC15m
2026-07-17 UAL1175 - Jul 17, 16:40 UTCJul 17, 17:09 UTC30m
2026-07-17 UAL872 - Jul 17, 03:50 UTCJul 17, 13:50 UTC10h 0m
2026-07-17 UAL872 - Jul 17, 02:20 UTCJul 17, 02:34 UTC15m
2026-07-16 UAL871 - Jul 16, 10:04 UTCJul 16, 10:20 UTC15m
2026-07-15 UAL871 SFO → TPE Jul 15, 22:23 UTCJul 16, 10:15 UTC11h 52m
2026-07-15 UAL871 - Jul 15, 22:25 UTCJul 16, 08:50 UTC10h 25m
2026-07-15 UAL838 - Jul 15, 08:35 UTCJul 15, 17:45 UTC9h 10m
2026-07-14 UAL79 - Jul 14, 15:55 UTCJul 15, 05:20 UTC13h 24m
2026-07-14 UAL2416 SFO → EWR Jul 14, 08:10 UTCJul 14, 13:05 UTC4h 55m
2026-07-13 UAL1844 - Jul 13, 00:15 UTCJul 13, 05:05 UTC4h 50m
2026-07-12 UAL78 NRT → EWR Jul 12, 08:51 UTCJul 12, 20:36 UTC11h 45m
2026-07-12 UAL78 - Jul 12, 08:35 UTCJul 12, 09:05 UTC30m
2026-07-11 UAL837 - Jul 11, 20:00 UTCJul 12, 06:01 UTC10h 0m
2026-07-11 UAL862 - Jul 11, 06:40 UTCJul 11, 08:20 UTC1h 40m
2026-07-11 UAL862 HKG → SFO Jul 11, 04:11 UTCJul 11, 17:04 UTC12h 53m
2026-07-11 UAL862 - Jul 11, 04:20 UTCJul 11, 04:35 UTC15m
2026-07-10 UAL877 SFO → HKG Jul 10, 08:05 UTCJul 10, 21:25 UTC13h 20m
2026-07-09 UAL810 MNL → SFO Jul 9, 13:41 UTCJul 10, 02:05 UTC12h 24m
2026-07-09 UAL810 - Jul 9, 13:45 UTCJul 10, 02:15 UTC12h 30m
2026-07-09 UAL810 MNL → SFO Jul 9, 13:41 UTCJul 10, 02:15 UTC12h 34m
2026-07-08 UAL809 SFO → MNL Jul 8, 22:03 UTCJul 9, 11:15 UTC13h 12m
2026-07-08 UAL809 SFO → MNL Jul 8, 22:05 UTCJul 9, 11:20 UTC13h 15m
2026-07-08 UAL838 - Jul 8, 08:40 UTCJul 8, 17:40 UTC9h 0m
2026-07-08 UAL838 NRT → SFO Jul 8, 08:41 UTCJul 8, 17:33 UTC8h 52m
2026-07-07 UAL79 EWR → NRT Jul 7, 16:35 UTCJul 8, 06:15 UTC13h 40m
2026-07-07 UAL2416 SFO → EWR Jul 7, 07:30 UTCJul 7, 12:20 UTC4h 50m
2026-07-06 UAL878 HKG → SFO Jul 6, 14:51 UTCJul 7, 03:02 UTC12h 11m

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 N2644U page for operator, model, and routing details .

Mode-S A290D0 frequently asked

What is Mode-S code A290D0?
A290D0 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N2644U.
Where is Mode-S A290D0 registered?
Mode-S code A290D0 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 A290D0 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 20:50 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A290D0, octal 50510320, decimal 10,653,904.
What flights does A290D0 operate?
Mode-S A290D0 has broadcast 20 distinct callsigns, including UAL810, UAL809, UAL871, UAL872, UAL862.