Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A57B4D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N452UA · AIRBUS A-320 · operated by UNITED AIRLINES INC

Hex
A57B4D
Octal
51275515
Decimal
10,845,005
Country
US
Tail
N452UA
Type
A320
No current signal · last broadcast Jul 26, 21:15 UTC
Flights observed
498
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:15 UTC

Last known position

Most recent position reported by Mode-S A57B4D.

Country allocation

The ICAO 24-bit address A57B4D 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
UAL1625 - 9 2026-07-01
UAL1180 United Airlines 7 2026-06-10
UAL596 United Airlines 5 2026-05-23
UAL575 United Airlines 5 2026-05-01
UAL2483 United Airlines 5 2026-06-11
UAL2357 United Airlines 5 2026-06-13
UAL2195 United Airlines 5 2026-05-15
UAL1564 - 5 2026-07-17
UAL730 - 4 2026-06-13
UAL720 - 4 2026-07-07
UAL697 - 4 2026-06-14
UAL654 United Airlines 4 2026-05-05
UAL649 United Airlines 4 2026-07-24
UAL333 United Airlines 4 2026-07-19
UAL2787 - 4 2026-07-07
UAL2682 - 4 2026-07-17
UAL2609 United Airlines 4 2026-07-22
UAL247 United Airlines 4 2026-06-16
UAL2329 United Airlines 4 2026-06-23
UAL2246 - 4 2026-06-25

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL1095 MYR → EWR Jul 26, 18:10 UTCJul 26, 21:15 UTC3h 5m
2026-07-26 UAL822 DEN → GRR Jul 26, 12:20 UTCJul 26, 16:10 UTC3h 50m
2026-07-26 UAL412 SFO → MEX Jul 26, 10:45 UTCJul 26, 11:00 UTC15m
2026-07-26 UAL412 SFO → MEX Jul 26, 07:05 UTCJul 26, 09:05 UTC2h 0m
2026-07-26 UAL292 EWR → SEA Jul 26, 02:45 UTCJul 26, 05:55 UTC3h 10m
2026-07-26 UAL292 EWR → SEA Jul 26, 02:38 UTCJul 26, 05:49 UTC3h 11m
2026-07-25 UAL1116 BOS → ORD Jul 25, 20:45 UTCJul 25, 23:55 UTC3h 10m
2026-07-25 UAL718 MEX → SFO Jul 25, 14:15 UTCJul 25, 17:50 UTC3h 35m
2026-07-25 UAL817 DEL → EWR Jul 25, 03:05 UTCJul 25, 03:15 UTC10m
2026-07-24 UAL817 DEL → EWR Jul 24, 23:10 UTCJul 25, 02:15 UTC3h 5m
2026-07-24 UAL2831 SEA → SFO Jul 24, 20:00 UTCJul 24, 21:50 UTC1h 50m
2026-07-24 UAL1708 MCO → EWR Jul 24, 17:00 UTCJul 24, 18:30 UTC1h 30m
2026-07-24 UAL2340 ORD → MCO Jul 24, 13:25 UTCJul 24, 14:15 UTC50m
2026-07-24 UAL2866 LAX → CLE Jul 24, 05:30 UTCJul 24, 06:15 UTC45m
2026-07-24 UAL649 SFO → EWR Jul 24, 04:25 UTCJul 24, 04:30 UTC5m
2026-07-24 UAL649 SFO → EWR Jul 24, 02:50 UTCJul 24, 04:30 UTC1h 40m
2026-07-24 UAL649 SFO → EWR Jul 24, 02:41 UTCJul 24, 04:09 UTC1h 28m
2026-07-23 UAL2602 ORD → MSN Jul 23, 23:45 UTCJul 24, 01:10 UTC1h 25m
2026-07-23 UAL1766 CLT → EWR Jul 23, 20:10 UTCJul 23, 22:35 UTC2h 25m
2026-07-23 UAL1048 DEN → BNA Jul 23, 16:16 UTCJul 23, 18:29 UTC2h 13m
2026-07-23 UAL1048 - Jul 23, 16:15 UTCJul 23, 17:15 UTC1h 0m
2026-07-23 UAL1846 ORD → CMH Jul 23, 12:20 UTCJul 23, 14:55 UTC2h 35m
2026-07-23 UAL1220 DEN → DTW Jul 23, 01:35 UTCJul 23, 04:00 UTC2h 25m
2026-07-22 UAL2609 LAX → BOS Jul 22, 20:30 UTCJul 23, 00:20 UTC3h 50m
2026-07-22 UAL1633 ORD → PHL Jul 22, 16:21 UTCJul 22, 19:04 UTC2h 43m
2026-07-22 UAL1633 ORD → PHL Jul 22, 16:30 UTCJul 22, 19:05 UTC2h 35m
2026-07-21 UAL2418 IAD → BDL Jul 21, 12:45 UTCJul 21, 14:20 UTC1h 35m
2026-07-21 UAL1762 SDF → DEN Jul 21, 04:55 UTCJul 21, 06:25 UTC1h 30m
2026-07-21 UAL2656 SNA → DEN Jul 21, 01:45 UTCJul 21, 03:45 UTC2h 0m
2026-07-20 UAL2657 IAD → EWR Jul 20, 22:55 UTCJul 21, 00:45 UTC1h 49m
2026-07-20 UAL1305 EWR → RDU Jul 20, 19:30 UTCJul 20, 21:15 UTC1h 45m
2026-07-20 UAL397 DEN → MSP Jul 20, 16:50 UTCJul 20, 18:25 UTC1h 35m
2026-07-20 UAL1256 RDU → DEN Jul 20, 13:00 UTCJul 20, 15:30 UTC2h 30m
2026-07-19 UAL2473 - Jul 19, 23:55 UTCJul 20, 02:15 UTC2h 20m
2026-07-19 UAL2447 AUS → DEN Jul 19, 20:05 UTCJul 19, 21:50 UTC1h 45m
2026-07-19 UAL2447 AUS → DEN Jul 19, 20:01 UTCJul 19, 21:48 UTC1h 47m
2026-07-19 UAL1026 DEN → AUS Jul 19, 16:25 UTCJul 19, 18:15 UTC1h 50m
2026-07-19 UAL724 - Jul 19, 13:25 UTCJul 19, 14:35 UTC1h 10m
2026-07-19 UAL333 BOS → LAX Jul 19, 01:45 UTCJul 19, 02:55 UTC1h 10m
2026-07-18 UAL2479 - Jul 18, 21:50 UTCJul 18, 23:40 UTC1h 50m
2026-07-18 UAL1819 - Jul 18, 20:15 UTCJul 18, 20:50 UTC35m
2026-07-18 UAL1819 IAH → SAT Jul 18, 20:26 UTCJul 18, 20:48 UTC22m
2026-07-18 UAL1747 - Jul 18, 18:40 UTCJul 18, 19:10 UTC30m
2026-07-18 UAL1747 AUS → IAH Jul 18, 18:32 UTCJul 18, 19:06 UTC34m
2026-07-18 UAL8102 YYZ → YQB Jul 18, 16:50 UTCJul 18, 17:20 UTC30m
2026-07-18 UAL8102 YYZ → YQB Jul 18, 16:59 UTCJul 18, 17:15 UTC16m
2026-07-18 UAL1345 - Jul 18, 10:35 UTCJul 18, 13:20 UTC2h 45m
2026-07-17 UAL313 BOI → SFO Jul 17, 23:55 UTCJul 18, 02:40 UTC2h 45m
2026-07-17 UAL2682 - Jul 17, 21:15 UTCJul 17, 21:55 UTC40m
2026-07-17 UAL1564 IAD → DFW Jul 17, 16:55 UTCJul 17, 19:25 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 N452UA page for operator, model, and routing details .

Mode-S A57B4D frequently asked

What is Mode-S code A57B4D?
A57B4D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N452UA.
Where is Mode-S A57B4D registered?
Mode-S code A57B4D 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 A57B4D broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 21:15 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A57B4D, octal 51275515, decimal 10,845,005.
What flights does A57B4D operate?
Mode-S A57B4D has broadcast 20 distinct callsigns, including UAL1625, UAL1180, UAL596, UAL575, UAL2483.