Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A55785

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N443UA · AIRBUS A-320 · operated by UNITED AIRLINES INC

Hex
A55785
Octal
51253605
Decimal
10,835,845
Country
US
Tail
N443UA
Type
A320
No current signal · last broadcast Jul 26, 21:15 UTC
Flights observed
432
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:15 UTC

Last known position

Most recent position reported by Mode-S A55785.

Country allocation

The ICAO 24-bit address A55785 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
UAL2232 - 7 2026-07-14
UAL773 - 6 2026-07-14
UAL226 United Airlines 6 2026-04-16
UAL2787 - 5 2026-07-09
UAL790 United Airlines 4 2026-06-10
UAL502 - 4 2026-07-15
UAL2602 - 4 2026-06-23
UAL2386 - 4 2026-06-24
UAL1949 United Airlines 4 2026-05-20
UAL1766 - 4 2026-07-10
UAL1366 - 4 2026-07-15
UAL1166 United Airlines 4 2026-07-02
UAL1116 - 4 2026-06-24
UAL720 - 3 2026-07-09
UAL521 United Airlines 3 2026-04-16
UAL489 United Airlines 3 2026-07-05
UAL480 United Airlines 3 2026-05-12
UAL396 United Airlines 3 2026-05-27
UAL304 United Airlines 3 2026-06-20
UAL2838 - 3 2026-07-09

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL1564 BOS → ORD Jul 26, 19:45 UTCJul 26, 21:15 UTC1h 30m
2026-07-26 UAL3884 IAD → ORD Jul 26, 17:10 UTCJul 26, 18:30 UTC1h 20m
2026-07-25 UAL2797 ORD → GRR Jul 25, 23:17 UTCJul 26, 00:50 UTC1h 33m
2026-07-25 UAL2797 ORD → GRR Jul 25, 23:25 UTCJul 26, 01:05 UTC1h 40m
2026-07-25 UAL2430 ORD → ALB Jul 25, 20:00 UTCJul 25, 21:30 UTC1h 30m
2026-07-25 UAL1410 IAH → PHL Jul 25, 16:25 UTCJul 25, 17:20 UTC55m
2026-07-25 UAL1803 CHS → EWR Jul 25, 14:15 UTCJul 25, 15:05 UTC50m
2026-07-17 UAL2792 - Jul 17, 23:14 UTCJul 18, 00:19 UTC1h 5m
2026-07-17 UAL2792 MCI → ORD Jul 17, 22:54 UTCJul 18, 00:14 UTC1h 20m
2026-07-17 UAL561 - Jul 17, 18:29 UTCJul 17, 19:30 UTC1h 0m
2026-07-17 UAL2774 DCA → ORD Jul 17, 13:45 UTCJul 17, 15:15 UTC1h 30m
2026-07-17 UAL2774 DCA → ORD Jul 17, 13:42 UTCJul 17, 14:57 UTC1h 15m
2026-07-17 UAL1369 ORD → DCA Jul 17, 00:45 UTCJul 17, 02:05 UTC1h 20m
2026-07-17 UAL1369 ORD → DCA Jul 17, 00:24 UTCJul 17, 02:02 UTC1h 38m
2026-07-16 UAL2467 - Jul 16, 19:25 UTCJul 16, 21:19 UTC1h 55m
2026-07-16 UAL1332 - Jul 16, 16:35 UTCJul 16, 18:05 UTC1h 30m
2026-07-16 UAL786 IAB → ORD Jul 16, 12:40 UTCJul 16, 14:05 UTC1h 25m
2026-07-16 UAL2762 - Jul 16, 02:40 UTCJul 16, 03:55 UTC1h 15m
2026-07-15 UAL1639 STL → ORD Jul 15, 23:10 UTCJul 15, 23:55 UTC45m
2026-07-15 UAL1639 DEN → STL Jul 15, 19:45 UTCJul 15, 21:25 UTC1h 40m
2026-07-15 UAL502 - Jul 15, 15:50 UTCJul 15, 17:55 UTC2h 5m
2026-07-15 UAL1366 IAD → BNA Jul 15, 12:40 UTCJul 15, 14:00 UTC1h 20m
2026-07-15 UAL1460 BNA → IAD Jul 15, 01:10 UTCJul 15, 02:30 UTC1h 20m
2026-07-14 UAL1109 DEN → BNA Jul 14, 20:10 UTCJul 14, 22:25 UTC2h 15m
2026-07-14 UAL2232 MSP → DEN Jul 14, 16:50 UTCJul 14, 18:15 UTC1h 25m
2026-07-14 UAL773 DEN → MSP Jul 14, 13:55 UTCJul 14, 15:30 UTC1h 35m
2026-07-14 UAL1035 SJC → DEN Jul 14, 01:35 UTCJul 14, 03:45 UTC2h 10m
2026-07-13 UAL1883 DEN → SJC Jul 13, 22:20 UTCJul 14, 00:30 UTC2h 10m
2026-07-13 UAL248 DFW → DEN Jul 13, 19:00 UTCJul 13, 20:30 UTC1h 30m
2026-07-13 UAL355 DEN → DFW Jul 13, 16:00 UTCJul 13, 17:20 UTC1h 20m
2026-07-13 UAL1925 GTF → DEN Jul 13, 12:32 UTCJul 13, 13:42 UTC1h 10m
2026-07-13 UAL1925 DEN → DEN Jul 13, 02:15 UTCJul 13, 13:45 UTC11h 30m
2026-07-12 UAL498 AWM → DEN Jul 12, 23:15 UTCJul 13, 01:10 UTC1h 55m
2026-07-12 UAL1112 - Jul 12, 19:55 UTCJul 12, 21:40 UTC1h 45m
2026-07-12 UAL2232 MSP → DEN Jul 12, 16:51 UTCJul 12, 18:12 UTC1h 21m
2026-07-12 UAL2232 MSP → DEN Jul 12, 16:45 UTCJul 12, 18:10 UTC1h 25m
2026-07-12 UAL773 DEN → MSP Jul 12, 13:50 UTCJul 12, 15:20 UTC1h 30m
2026-07-12 UAL2656 - Jul 12, 01:30 UTCJul 12, 03:15 UTC1h 45m
2026-07-12 UAL2656 SNA → DEN Jul 12, 01:39 UTCJul 12, 03:22 UTC1h 43m
2026-07-11 UAL2657 - Jul 11, 22:25 UTCJul 12, 00:15 UTC1h 50m
2026-07-11 UAL1741 ABQ → DEN Jul 11, 19:45 UTCJul 11, 20:40 UTC55m
2026-07-11 UAL1402 DEN → ABQ Jul 11, 17:35 UTCJul 11, 18:30 UTC55m
2026-07-11 UAL2742 LAX → SFO Jul 11, 15:11 UTCJul 11, 16:07 UTC56m
2026-07-11 UAL2742 LAX → SFO Jul 11, 14:55 UTCJul 11, 16:05 UTC1h 10m
2026-07-11 UAL645 DEN → FSD Jul 11, 00:10 UTCJul 11, 01:15 UTC1h 5m
2026-07-10 UAL1766 - Jul 10, 19:45 UTCJul 10, 22:05 UTC2h 21m
2026-07-10 UAL1048 DEN → BNA Jul 10, 16:10 UTCJul 10, 18:20 UTC2h 10m
2026-07-10 UAL724 ELP → DEN Jul 10, 13:14 UTCJul 10, 14:34 UTC1h 20m
2026-07-10 UAL333 DEN → DEN Jul 10, 02:55 UTCJul 10, 14:35 UTC11h 40m
2026-07-09 UAL720 - Jul 9, 21:15 UTCJul 10, 00:30 UTC3h 15m

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 N443UA page for operator, model, and routing details .

Mode-S A55785 frequently asked

What is Mode-S code A55785?
A55785 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N443UA.
Where is Mode-S A55785 registered?
Mode-S code A55785 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 A55785 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 A55785, octal 51253605, decimal 10,835,845.
What flights does A55785 operate?
Mode-S A55785 has broadcast 20 distinct callsigns, including UAL2232, UAL773, UAL226, UAL2787, UAL790.