Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A254D7

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N24973 · BOEING 787-9 Dreamliner · operated by UNITED AIRLINES INC

Hex
A254D7
Octal
50452327
Decimal
10,638,551
Country
US
Tail
N24973
Type
B789
No current signal · last broadcast Jul 22, 02:20 UTC
Flights observed
207
Distinct callsigns
20
Country
US
Last broadcast
Jul 22, 02:20 UTC

Last known position

Most recent position reported by Mode-S A254D7.

Country allocation

The ICAO 24-bit address A254D7 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
UAL62 - 10 2026-06-27
UAL198 United Airlines 9 2026-06-04
UAL806 - 7 2026-06-19
UAL805 - 7 2026-06-18
UAL7 - 7 2026-06-28
UAL63 - 7 2026-06-28
UAL6 - 7 2026-06-26
UAL33 - 7 2026-07-16
UAL61 United Airlines 6 2026-06-09
UAL28 United Airlines 6 2026-06-10
UAL1757 - 6 2026-06-17
UAL32 - 5 2026-06-25
UAL1849 United Airlines 5 2026-06-17
UAL893 United Airlines 4 2026-05-08
UAL892 United Airlines 4 2026-05-09
UAL83 United Airlines 4 2026-06-23
UAL820 United Airlines 4 2026-05-27
UAL760 - 4 2026-07-14
UAL60 United Airlines 4 2026-06-08
UAL29 United Airlines 4 2026-06-09

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-21 UAL1227 PHX → IAD Jul 21, 20:45 UTCJul 22, 02:15 UTC5h 30m
2026-07-21 UAL2222 - Jul 21, 07:40 UTCJul 21, 08:45 UTC1h 5m
2026-07-20 UAL2222 - Jul 20, 18:05 UTCJul 20, 18:20 UTC15m
2026-07-20 UAL2222 CPT → EWR Jul 20, 18:12 UTCJul 21, 08:38 UTC14h 26m
2026-07-20 UAL1122 EWR → CPT Jul 20, 01:40 UTCJul 20, 15:35 UTC13h 55m
2026-07-18 UAL1855 ORD → BOS Jul 18, 23:20 UTCJul 19, 04:05 UTC4h 45m
2026-07-18 UAL153 - Jul 18, 04:45 UTCJul 18, 18:25 UTC13h 40m
2026-07-18 UAL153 - Jul 18, 02:14 UTCJul 18, 02:29 UTC15m
2026-07-18 UAL153 SGN → HKG Jul 18, 00:19 UTCJul 18, 02:30 UTC2h 11m
2026-07-17 UAL152 - Jul 17, 13:50 UTCJul 17, 14:04 UTC15m
2026-07-17 UAL152 HKG → SGN Jul 17, 13:04 UTCJul 17, 15:52 UTC2h 48m
2026-07-16 UAL152 - Jul 16, 21:40 UTCJul 17, 10:44 UTC13h 5m
2026-07-16 UAL33 - Jul 16, 08:10 UTCJul 16, 17:45 UTC9h 35m
2026-07-15 UAL143 DEN → NRT Jul 15, 18:00 UTCJul 16, 05:00 UTC11h 0m
2026-07-14 UAL761 - Jul 14, 14:35 UTCJul 15, 00:20 UTC9h 44m
2026-07-14 UAL760 DEN → MUC Jul 14, 02:50 UTCJul 14, 12:09 UTC9h 19m
2026-07-14 UAL760 - Jul 14, 02:50 UTCJul 14, 12:15 UTC9h 25m
2026-07-13 UAL263 - Jul 13, 14:20 UTCJul 13, 23:05 UTC8h 45m
2026-07-13 UAL262 DEN → LHR Jul 13, 03:20 UTCJul 13, 11:45 UTC8h 25m
2026-07-13 UAL177 DEN → FCO Jul 13, 00:08 UTCJul 13, 10:00 UTC9h 52m
2026-07-11 UAL26 LHR → DEN Jul 11, 10:55 UTCJul 11, 20:00 UTC9h 5m
2026-07-11 UAL26 LHR → DEN Jul 11, 10:50 UTCJul 11, 19:53 UTC9h 3m
2026-07-11 UAL27 DEN → LHR Jul 11, 00:20 UTCJul 11, 08:45 UTC8h 25m
2026-07-10 UAL181 - Jul 10, 10:00 UTCJul 10, 19:30 UTC9h 30m
2026-07-09 UAL182 DEN → FRA Jul 9, 22:30 UTCJul 10, 07:35 UTC9h 5m
2026-07-09 UAL142 - Jul 9, 07:55 UTCJul 9, 18:00 UTC10h 5m
2026-07-09 UAL142 NRT → DEN Jul 9, 07:55 UTCJul 9, 18:00 UTC10h 5m
2026-07-08 UAL143 DEN → NRT Jul 8, 18:04 UTCJul 9, 05:28 UTC11h 24m
2026-07-08 UAL143 DEN → NRT Jul 8, 18:05 UTCJul 9, 05:30 UTC11h 25m
2026-07-07 UAL761 MUC → DEN Jul 7, 14:35 UTCJul 8, 01:15 UTC10h 40m
2026-07-07 UAL760 - Jul 7, 02:45 UTCJul 7, 12:05 UTC9h 20m
2026-07-06 UAL263 - Jul 6, 14:45 UTCJul 6, 23:45 UTC9h 0m
2026-07-06 UAL262 DEN → LHR Jul 6, 03:00 UTCJul 6, 11:30 UTC8h 30m
2026-07-05 UAL761 MUC → DEN Jul 5, 14:40 UTCJul 6, 00:40 UTC10h 0m
2026-07-05 UAL760 - Jul 5, 02:35 UTCJul 5, 11:50 UTC9h 15m
2026-07-04 UAL263 - Jul 4, 14:10 UTCJul 4, 23:20 UTC9h 10m
2026-07-04 UAL263 LHR → DEN Jul 4, 14:14 UTCJul 4, 23:17 UTC9h 3m
2026-07-04 UAL262 DEN → LHR Jul 4, 02:40 UTCJul 4, 11:05 UTC8h 25m
2026-07-03 UAL178 KIX → GUM Jul 3, 12:50 UTCJul 4, 00:05 UTC11h 15m
2026-07-03 UAL177 - Jul 3, 00:00 UTCJul 3, 09:20 UTC9h 20m
2026-07-02 UAL26 - Jul 2, 10:50 UTCJul 2, 20:05 UTC9h 15m
2026-07-02 UAL27 DEN → LHR Jul 2, 00:20 UTCJul 2, 08:45 UTC8h 25m
2026-07-01 UAL26 - Jul 1, 10:50 UTCJul 1, 19:50 UTC9h 0m
2026-07-01 UAL27 DEN → LHR Jul 1, 00:10 UTCJul 1, 08:40 UTC8h 30m
2026-06-30 UAL181 FRA → DEN Jun 30, 09:55 UTCJun 30, 19:25 UTC9h 30m
2026-06-29 UAL182 DEN → FRA Jun 29, 22:15 UTCJun 30, 07:00 UTC8h 45m
2026-06-29 UAL142 NRT → DEN Jun 29, 08:04 UTCJun 29, 17:40 UTC9h 35m
2026-06-28 UAL7 - Jun 28, 16:09 UTCJun 29, 04:55 UTC12h 45m
2026-06-28 UAL63 - Jun 28, 01:10 UTCJun 28, 10:19 UTC9h 10m
2026-06-28 UAL63 GRU → IAH Jun 28, 01:11 UTCJun 28, 10:21 UTC9h 10m

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 N24973 page for operator, model, and routing details .

Mode-S A254D7 frequently asked

What is Mode-S code A254D7?
A254D7 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N24973.
Where is Mode-S A254D7 registered?
Mode-S code A254D7 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 A254D7 broadcasting right now?
No active broadcast right now. Last signal was Jul 22, 02:20 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A254D7, octal 50452327, decimal 10,638,551.
What flights does A254D7 operate?
Mode-S A254D7 has broadcast 20 distinct callsigns, including UAL62, UAL198, UAL806, UAL805, UAL7.