Apparatus

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sensors Mode-S transponder

A1BB45

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N210UA · BOEING 777-200 · operated by UNITED AIRLINES INC

Hex
A1BB45
Octal
50335505
Decimal
10,599,237
Country
US
Tail
N210UA
Type
B772
Broadcasting now · 37,000 ft
Flights observed
271
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 04:20 UTC

Current position

A1BB45 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A1BB45 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
UAL384 United Airlines 44 2026-07-23
UAL1805 United Airlines 34 2026-07-25
UAL1806 - 31 2026-07-19
UAL383 United Airlines 28 2026-07-23
UAL1736 United Airlines 22 2026-07-24
UAL1735 United Airlines 18 2026-07-24
UAL252 - 10 2026-06-30
UAL300 United Airlines 8 2026-07-22
UAL253 - 7 2026-06-30
UAL1170 United Airlines 7 2026-06-07
UAL2358 United Airlines 6 2026-06-26
UAL1157 United Airlines 6 2026-06-24
UAL1731 United Airlines 5 2026-04-27
UAL2004 United Airlines 4 2026-04-18
UAL1726 United Airlines 4 2026-04-17
UAL1509 United Airlines 4 2026-04-23
UAL2391 United Airlines 3 2026-05-20
UAL1818 United Airlines 3 2026-07-25
UAL1758 United Airlines 3 2026-04-26
UAL1604 United Airlines 3 2026-05-20

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-25 UAL1818 FLL → EWR Jul 25, 23:45 UTCJul 26, 04:10 UTC4h 25m
2026-07-25 UAL1805 LAS → EWR Jul 25, 12:20 UTCJul 25, 12:30 UTC10m
2026-07-25 UAL1805 LAS → EWR Jul 25, 07:40 UTCJul 25, 08:15 UTC35m
2026-07-25 UAL1805 LAS → EWR Jul 25, 03:25 UTCJul 25, 05:30 UTC2h 5m
2026-07-24 UAL1735 LAS → EWR Jul 24, 09:30 UTCJul 24, 11:50 UTC2h 20m
2026-07-24 UAL1736 DEN → OGG Jul 24, 00:50 UTCJul 24, 01:05 UTC15m
2026-07-23 UAL1736 DEN → OGG Jul 23, 18:25 UTCJul 23, 20:30 UTC2h 5m
2026-07-23 UAL383 HNL → DEN Jul 23, 09:35 UTCJul 23, 11:55 UTC2h 20m
2026-07-23 UAL383 HNL → DEN Jul 23, 06:05 UTCJul 23, 06:15 UTC10m
2026-07-23 UAL384 DEN → HNL Jul 23, 00:55 UTCJul 23, 01:10 UTC15m
2026-07-22 UAL384 DEN → HNL Jul 22, 18:20 UTCJul 22, 20:25 UTC2h 5m
2026-07-22 UAL383 HNL → DEN Jul 22, 11:10 UTCJul 22, 11:40 UTC30m
2026-07-22 UAL300 SFO → HNL Jul 22, 02:00 UTCJul 22, 02:25 UTC25m
2026-07-21 UAL300 SFO → HNL Jul 21, 21:30 UTCJul 21, 22:05 UTC35m
2026-07-21 UAL3926 FRA → IAD Jul 21, 17:24 UTCJul 21, 19:13 UTC1h 49m
2026-07-21 UAL3926 FRA → IAD Jul 21, 17:25 UTCJul 21, 19:25 UTC2h 0m
2026-07-19 UAL1806 - Jul 19, 07:55 UTCJul 19, 13:55 UTC6h 0m
2026-07-19 UAL1805 - Jul 19, 05:00 UTCJul 19, 05:20 UTC20m
2026-07-18 UAL1805 - Jul 18, 22:30 UTCJul 19, 00:50 UTC2h 20m
2026-07-18 UAL1806 - Jul 18, 08:10 UTCJul 18, 08:25 UTC15m
2026-07-18 UAL1806 HNL → DEN Jul 18, 07:59 UTCJul 18, 14:09 UTC6h 10m
2026-07-17 UAL1805 DEN → HNL Jul 17, 22:33 UTCJul 18, 05:15 UTC6h 42m
2026-07-17 UAL1805 - Jul 17, 22:35 UTCJul 18, 00:55 UTC2h 20m
2026-07-17 UAL383 - Jul 17, 06:05 UTCJul 17, 12:04 UTC6h 0m
2026-07-17 UAL384 - Jul 17, 00:50 UTCJul 17, 01:09 UTC20m
2026-07-16 UAL384 - Jul 16, 18:40 UTCJul 16, 20:49 UTC2h 10m
2026-07-16 UAL383 - Jul 16, 06:05 UTCJul 16, 12:09 UTC6h 5m
2026-07-16 UAL384 - Jul 16, 00:50 UTCJul 16, 01:05 UTC15m
2026-07-15 UAL384 - Jul 15, 18:30 UTCJul 15, 20:45 UTC2h 15m
2026-07-13 UAL1806 - Jul 13, 12:10 UTCJul 13, 14:15 UTC2h 5m
2026-07-13 UAL1806 - Jul 13, 08:01 UTCJul 13, 08:20 UTC20m
2026-07-12 UAL1805 DEN → HNL Jul 12, 22:23 UTCJul 13, 04:54 UTC6h 31m
2026-07-12 UAL1805 - Jul 12, 22:25 UTCJul 13, 04:55 UTC6h 30m
2026-07-12 UAL1735 - Jul 12, 10:05 UTCJul 12, 12:15 UTC2h 10m
2026-07-11 UAL1736 DEN → OGG Jul 11, 18:23 UTCJul 12, 00:32 UTC6h 9m
2026-07-11 UAL1736 - Jul 11, 18:15 UTCJul 11, 20:35 UTC2h 20m
2026-07-09 UAL383 - Jul 9, 06:00 UTCJul 9, 06:15 UTC15m
2026-07-09 UAL383 HNL → DEN Jul 9, 05:58 UTCJul 9, 12:00 UTC6h 2m
2026-07-09 UAL384 - Jul 9, 00:40 UTCJul 9, 01:00 UTC20m
2026-07-08 UAL384 - Jul 8, 18:20 UTCJul 8, 20:40 UTC2h 20m
2026-07-05 UAL1806 - Jul 5, 11:45 UTCJul 5, 14:05 UTC2h 20m
2026-07-05 UAL1806 - Jul 5, 08:00 UTCJul 5, 08:15 UTC15m
2026-07-04 UAL1805 DEN → HNL Jul 4, 22:23 UTCJul 5, 05:06 UTC6h 43m
2026-07-04 UAL1805 DEN → HNL Jul 4, 22:30 UTCJul 5, 05:10 UTC6h 40m
2026-07-04 UAL383 - Jul 4, 06:00 UTCJul 4, 11:50 UTC5h 50m
2026-07-04 UAL384 DEN → HNL Jul 4, 00:40 UTCJul 4, 00:55 UTC15m
2026-07-03 UAL384 DEN → HNL Jul 3, 18:15 UTCJul 3, 20:30 UTC2h 15m
2026-07-03 UAL383 - Jul 3, 06:05 UTCJul 3, 11:55 UTC5h 50m
2026-07-03 UAL384 DEN → HNL Jul 3, 00:45 UTCJul 3, 01:05 UTC20m
2026-07-02 UAL384 DEN → HNL Jul 2, 18:25 UTCJul 2, 20:35 UTC2h 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 N210UA page for operator, model, and routing details .

Mode-S A1BB45 frequently asked

What is Mode-S code A1BB45?
A1BB45 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N210UA.
Where is Mode-S A1BB45 registered?
Mode-S code A1BB45 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 A1BB45 broadcasting right now?
Yes. Mode-S A1BB45 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A1BB45, octal 50335505, decimal 10,599,237.
What flights does A1BB45 operate?
Mode-S A1BB45 has broadcast 20 distinct callsigns, including UAL384, UAL1805, UAL1806, UAL383, UAL1736.