Apparatus

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sensors Mode-S transponder

A54299

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N438UA · AIRBUS A-320 · operated by UNITED AIRLINES INC

Hex
A54299
Octal
51241231
Decimal
10,830,489
Country
US
Tail
N438UA
Type
A320
No current signal · last broadcast Jul 26, 21:40 UTC
Flights observed
555
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:40 UTC

Last known position

Most recent position reported by Mode-S A54299.

Country allocation

The ICAO 24-bit address A54299 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
UAL561 United Airlines 8 2026-07-26
UAL426 - 7 2026-06-21
UAL2483 - 6 2026-07-04
UAL2426 - 6 2026-07-11
UAL2340 - 6 2026-07-15
UAL224 - 6 2026-07-02
UAL817 United Airlines 5 2026-05-15
UAL739 United Airlines 5 2026-07-24
UAL718 United Airlines 5 2026-05-16
UAL455 - 5 2026-06-29
UAL2682 United Airlines 5 2026-07-21
UAL2051 United Airlines 5 2026-07-19
UAL1564 - 5 2026-07-21
UAL1398 - 5 2026-06-13
UAL1193 - 5 2026-07-10
UAL730 - 4 2026-06-16
UAL530 - 4 2026-06-19
UAL490 United Airlines 4 2026-06-12
UAL387 United Airlines 4 2026-06-02
UAL303 - 4 2026-06-18

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL2792 IAD → SFO Jul 26, 20:20 UTCJul 26, 21:30 UTC1h 10m
2026-07-26 UAL561 BOS → ORD Jul 26, 18:10 UTCJul 26, 19:05 UTC55m
2026-07-26 UAL2774 NRT → SFO Jul 26, 13:40 UTCJul 26, 15:15 UTC1h 35m
2026-07-25 UAL1369 IAH → EWR Jul 25, 23:57 UTCJul 26, 00:58 UTC1h 1m
2026-07-25 UAL1369 IAH → EWR Jul 25, 23:40 UTCJul 26, 01:00 UTC1h 20m
2026-07-25 UAL1655 BNA → EWR Jul 25, 18:48 UTCJul 25, 21:13 UTC2h 25m
2026-07-25 UAL1655 BNA → EWR Jul 25, 18:35 UTCJul 25, 21:30 UTC2h 55m
2026-07-25 UAL764 DEN → BOS Jul 25, 14:05 UTCJul 25, 17:20 UTC3h 15m
2026-07-25 UAL764 DEN → BOS Jul 25, 14:10 UTCJul 25, 17:19 UTC3h 9m
2026-07-25 UAL2137 ORD → SLC Jul 25, 11:25 UTCJul 25, 11:55 UTC30m
2026-07-24 UAL1178 SMF → EWR Jul 24, 23:30 UTCJul 25, 00:00 UTC30m
2026-07-24 UAL739 SFO → AUS Jul 24, 20:25 UTCJul 24, 21:40 UTC1h 15m
2026-07-24 UAL247 DTW → ORD Jul 24, 18:00 UTCJul 24, 19:00 UTC1h 0m
2026-07-24 UAL704 IAH → EWR Jul 24, 14:35 UTCJul 24, 16:10 UTC1h 35m
2026-07-24 UAL1269 LGA → IAH Jul 24, 11:35 UTCJul 24, 12:55 UTC1h 20m
2026-07-24 UAL1476 DEN → EUG Jul 24, 00:15 UTCJul 24, 01:35 UTC1h 20m
2026-07-23 UAL2207 ORD → PIT Jul 23, 21:15 UTCJul 23, 22:15 UTC1h 0m
2026-07-23 UAL2605 - Jul 23, 18:25 UTCJul 23, 19:05 UTC40m
2026-07-23 UAL2605 SJC → DEN Jul 23, 18:35 UTCJul 23, 18:45 UTC10m
2026-07-23 UAL2807 ORD → ORF Jul 23, 16:10 UTCJul 23, 16:45 UTC35m
2026-07-23 UAL466 AUS → EWR Jul 23, 13:05 UTCJul 23, 14:00 UTC55m
2026-07-23 UAL466 AUS → EWR Jul 23, 13:13 UTCJul 23, 13:51 UTC38m
2026-07-23 UAL1492 PHL → IAH Jul 23, 03:15 UTCJul 23, 04:00 UTC45m
2026-07-22 UAL1084 IAH → CMH Jul 22, 23:45 UTCJul 23, 00:50 UTC1h 5m
2026-07-22 UAL1934 LAS → DEN Jul 22, 20:15 UTCJul 22, 22:35 UTC2h 20m
2026-07-22 UAL1747 TPA → EWR Jul 22, 17:35 UTCJul 22, 18:10 UTC35m
2026-07-22 UAL1823 SFO → DEN Jul 22, 15:30 UTCJul 22, 15:55 UTC25m
2026-07-22 UAL1823 SFO → DEN Jul 22, 15:39 UTCJul 22, 15:52 UTC13m
2026-07-22 UAL1345 MIA → EWR Jul 22, 11:10 UTCJul 22, 13:15 UTC2h 5m
2026-07-22 UAL313T SNA → SFO Jul 22, 00:01 UTCJul 22, 02:28 UTC2h 27m
2026-07-21 UAL313T SNA → SFO Jul 21, 23:50 UTCJul 22, 02:15 UTC2h 25m
2026-07-21 UAL2682 EWR → RDU Jul 21, 21:10 UTCJul 21, 21:55 UTC45m
2026-07-21 UAL1564 IAD → DFW Jul 21, 17:20 UTCJul 21, 19:50 UTC2h 30m
2026-07-21 UAL1535 - Jul 21, 14:40 UTCJul 21, 15:25 UTC45m
2026-07-21 UAL529 IAD → RDU Jul 21, 12:35 UTCJul 21, 13:15 UTC40m
2026-07-21 UAL1524 IAH → EWR Jul 21, 10:15 UTCJul 21, 10:55 UTC40m
2026-07-21 UAL2677 CLE → DEN Jul 21, 03:10 UTCJul 21, 03:40 UTC30m
2026-07-20 UAL1460 SFO → DEN Jul 20, 23:55 UTCJul 21, 01:15 UTC1h 20m
2026-07-20 UAL1109 DEN → BNA Jul 20, 20:25 UTCJul 20, 22:35 UTC2h 10m
2026-07-20 UAL2232 ORD → MSP Jul 20, 17:00 UTCJul 20, 18:35 UTC1h 35m
2026-07-20 UAL2232 ORD → MSP Jul 20, 16:51 UTCJul 20, 18:38 UTC1h 47m
2026-07-20 UAL773 - Jul 20, 14:30 UTCJul 20, 15:40 UTC1h 10m
2026-07-20 UAL773 DEN → MSP Jul 20, 13:58 UTCJul 20, 14:13 UTC15m
2026-07-20 UAL773 DEN → MSP Jul 20, 14:15 UTCJul 20, 15:40 UTC1h 25m
2026-07-19 UAL1790 EWR → MYR Jul 19, 20:10 UTCJul 19, 22:25 UTC2h 15m
2026-07-19 UAL1578 - Jul 19, 17:55 UTCJul 19, 18:45 UTC50m
2026-07-19 UAL2051 SFO → YVR Jul 19, 12:40 UTCJul 19, 15:55 UTC3h 15m
2026-07-18 UAL692 - Jul 18, 21:55 UTCJul 19, 00:50 UTC2h 55m
2026-07-18 UAL1613 EWR → FLL Jul 18, 18:30 UTCJul 18, 20:00 UTC1h 30m
2026-07-18 UAL2265 - Jul 18, 16:20 UTCJul 18, 17:30 UTC1h 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 N438UA page for operator, model, and routing details .

Mode-S A54299 frequently asked

What is Mode-S code A54299?
A54299 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N438UA.
Where is Mode-S A54299 registered?
Mode-S code A54299 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 A54299 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 21:40 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A54299, octal 51241231, decimal 10,830,489.
What flights does A54299 operate?
Mode-S A54299 has broadcast 20 distinct callsigns, including UAL561, UAL426, UAL2483, UAL2426, UAL2340.