Apparatus

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sensors Mode-S transponder

ABB440

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N853UA · AIRBUS A-319 · operated by UNITED AIRLINES INC

Hex
ABB440
Octal
52732100
Decimal
11,252,800
Country
US
Tail
N853UA
Type
A319
No current signal · last broadcast Jul 26, 19:45 UTC
Flights observed
516
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 19:45 UTC

Last known position

Most recent position reported by Mode-S ABB440.

Country allocation

The ICAO 24-bit address ABB440 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
UAL412 United Airlines 7 2026-07-21
UAL1846 - 7 2026-07-02
UAL822 United Airlines 6 2026-07-21
UAL1027 - 6 2026-07-11
UAL472 - 5 2026-06-29
UAL2115 - 5 2026-07-04
UAL2097 United Airlines 5 2026-07-21
UAL1453 - 5 2026-07-20
UAL1282 - 5 2026-07-01
UAL792 - 4 2026-06-22
UAL738 - 4 2026-07-12
UAL516 - 4 2026-06-18
UAL471 - 4 2026-06-18
UAL2775 United Airlines 4 2026-06-10
UAL259 United Airlines 4 2026-07-19
UAL2130 - 4 2026-06-29
UAL1874 United Airlines 4 2026-06-03
UAL1662 United Airlines 4 2026-04-23
UAL1464 United Airlines 4 2026-05-28
UAL785 United Airlines 3 2026-07-23

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL688 IAD → BOS Jul 26, 17:45 UTCJul 26, 19:40 UTC1h 55m
2026-07-26 UAL1484 LAX → SFO Jul 26, 13:55 UTCJul 26, 14:55 UTC1h 0m
2026-07-26 UAL2849 EWR → DOM Jul 26, 10:50 UTCJul 26, 12:20 UTC1h 30m
2026-07-26 UAL1504 ORD → DCA Jul 26, 00:15 UTCJul 26, 01:55 UTC1h 40m
2026-07-25 UAL2680 SEA → EWR Jul 25, 20:40 UTCJul 25, 21:20 UTC40m
2026-07-25 UAL2680 SEA → EWR Jul 25, 20:38 UTCJul 25, 21:17 UTC39m
2026-07-25 UAL1687 MSY → SFO Jul 25, 17:10 UTCJul 25, 19:05 UTC1h 55m
2026-07-25 UAL697 DCA → IAH Jul 25, 12:30 UTCJul 25, 15:05 UTC2h 35m
2026-07-24 UAL2296 SFO → IAH Jul 24, 22:15 UTCJul 25, 00:55 UTC2h 40m
2026-07-24 UAL1469 DFW → IAH Jul 24, 18:35 UTCJul 24, 20:30 UTC1h 55m
2026-07-24 UAL2281 CVG → IAH Jul 24, 15:10 UTCJul 24, 16:50 UTC1h 40m
2026-07-24 UAL1982 ORD → LGA Jul 24, 11:30 UTCJul 24, 13:35 UTC2h 5m
2026-07-24 UAL1780 PDX → SFO Jul 24, 01:45 UTCJul 24, 03:35 UTC1h 50m
2026-07-23 UAL1420 MCO → EWR Jul 23, 21:45 UTCJul 23, 23:55 UTC2h 10m
2026-07-23 UAL587 EWR → MSP Jul 23, 19:45 UTCJul 23, 20:20 UTC35m
2026-07-23 UAL587 EWR → MSP Jul 23, 19:45 UTCJul 23, 20:16 UTC31m
2026-07-23 UAL705 PVR → SFO Jul 23, 15:15 UTCJul 23, 16:25 UTC1h 10m
2026-07-23 UAL2753 LAX → SFO Jul 23, 12:40 UTCJul 23, 13:50 UTC1h 10m
2026-07-23 UAL2753 LAX → SFO Jul 23, 12:48 UTCJul 23, 13:43 UTC55m
2026-07-23 UAL785 ORD → PWM Jul 23, 02:55 UTCJul 23, 03:00 UTC5m
2026-07-23 UAL785 ORD → PWM Jul 23, 01:25 UTCJul 23, 03:00 UTC1h 35m
2026-07-23 UAL785 ORD → PWM Jul 23, 01:11 UTCJul 23, 02:39 UTC1h 28m
2026-07-22 UAL1991 EWR → SFO Jul 22, 21:15 UTCJul 22, 23:05 UTC1h 50m
2026-07-22 UAL2454 ORD → LGA Jul 22, 15:45 UTCJul 22, 18:40 UTC2h 55m
2026-07-21 UAL2842 SFO → DFW Jul 21, 18:05 UTCJul 21, 21:15 UTC3h 10m
2026-07-21 UAL822 DEN → GRR Jul 21, 11:35 UTCJul 21, 15:30 UTC3h 55m
2026-07-21 UAL412 SFO → MEX Jul 21, 10:05 UTCJul 21, 10:15 UTC10m
2026-07-21 UAL412 SFO → MEX Jul 21, 06:25 UTCJul 21, 08:25 UTC2h 0m
2026-07-21 UAL2097 SFO → EWR Jul 21, 03:40 UTCJul 21, 05:20 UTC1h 40m
2026-07-21 UAL543 IAH → MCO Jul 21, 01:00 UTCJul 21, 02:25 UTC1h 25m
2026-07-20 UAL1453 BUR → SFO Jul 20, 22:45 UTCJul 20, 23:40 UTC55m
2026-07-20 UAL2154 ORD → TPA Jul 20, 17:35 UTCJul 20, 19:30 UTC1h 55m
2026-07-20 UAL384 - Jul 20, 13:15 UTCJul 20, 15:40 UTC2h 25m
2026-07-20 UAL1470 EWR → SDQ Jul 20, 00:20 UTCJul 20, 02:30 UTC2h 10m
2026-07-19 UAL259 DEN → MCO Jul 19, 19:55 UTCJul 19, 22:05 UTC2h 10m
2026-07-19 UAL487 PHX → SFO Jul 19, 17:50 UTCJul 19, 18:25 UTC35m
2026-07-19 UAL488 BUR → SFO Jul 19, 14:10 UTCJul 19, 15:00 UTC50m
2026-07-19 UAL1321 MIA → EWR Jul 19, 01:30 UTCJul 19, 02:20 UTC50m
2026-07-18 UAL1453 BUR → SFO Jul 18, 20:50 UTCJul 18, 21:40 UTC50m
2026-07-18 UAL8123 DEN → BUR Jul 18, 17:45 UTCJul 18, 19:35 UTC1h 50m
2026-07-18 UAL384 - Jul 18, 13:55 UTCJul 18, 16:15 UTC2h 20m
2026-07-18 UAL1470 DEN → LEX Jul 18, 00:29 UTCJul 18, 02:45 UTC2h 15m
2026-07-17 UAL259 - Jul 17, 20:35 UTCJul 17, 22:45 UTC2h 10m
2026-07-17 UAL487 - Jul 17, 18:44 UTCJul 17, 19:35 UTC50m
2026-07-17 UAL2818 PDX → SFO Jul 17, 15:55 UTCJul 17, 17:30 UTC1h 35m
2026-07-17 UAL2818 PDX → SFO Jul 17, 15:42 UTCJul 17, 17:24 UTC1h 42m
2026-07-17 UAL2413 - Jul 17, 04:04 UTCJul 17, 05:15 UTC1h 10m
2026-07-17 UAL2413 SFO → PDX Jul 17, 04:14 UTCJul 17, 05:13 UTC59m
2026-07-16 UAL1863 - Jul 16, 21:45 UTCJul 17, 02:10 UTC4h 25m
2026-07-16 UAL1642 - Jul 16, 16:00 UTCJul 16, 20:05 UTC4h 5m

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 N853UA page for operator, model, and routing details .

Mode-S ABB440 frequently asked

What is Mode-S code ABB440?
ABB440 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N853UA.
Where is Mode-S ABB440 registered?
Mode-S code ABB440 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 ABB440 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 19:45 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex ABB440, octal 52732100, decimal 11,252,800.
What flights does ABB440 operate?
Mode-S ABB440 has broadcast 20 distinct callsigns, including UAL412, UAL1846, UAL822, UAL1027, UAL472.