Apparatus

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sensors Mode-S transponder

A3A0CF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N33289 · BOEING 737-800 · operated by UNITED AIRLINES INC

Hex
A3A0CF
Octal
50720317
Decimal
10,723,535
Country
US
Tail
N33289
Type
B738
No current signal · last broadcast Jul 26, 21:05 UTC
Flights observed
488
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:05 UTC

Last known position

Most recent position reported by Mode-S A3A0CF.

Country allocation

The ICAO 24-bit address A3A0CF 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
UAL694 United Airlines 6 2026-05-15
UAL645 United Airlines 6 2026-07-25
UAL2446 - 6 2026-07-03
UAL248 United Airlines 5 2026-05-23
UAL2455 United Airlines 4 2026-07-22
UAL2306 - 4 2026-06-30
UAL2270 United Airlines 4 2026-06-01
UAL1990 - 4 2026-06-15
UAL1919 United Airlines 4 2026-06-03
UAL1816 - 4 2026-07-19
UAL730 United Airlines 3 2026-04-17
UAL622 - 3 2026-06-15
UAL586 United Airlines 3 2026-07-26
UAL466 United Airlines 3 2026-06-15
UAL464 - 3 2026-07-07
UAL456 - 3 2026-07-05
UAL450 United Airlines 3 2026-04-28
UAL2742 United Airlines 3 2026-05-17
UAL2724 - 3 2026-07-05
UAL2655 - 3 2026-07-11

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL586 DEN → MCI Jul 26, 20:05 UTCJul 26, 21:05 UTC1h 0m
2026-07-26 UAL640 YVR → DEN Jul 26, 16:25 UTCJul 26, 18:40 UTC2h 15m
2026-07-26 UAL1910 EWR → DEN Jul 26, 03:00 UTCJul 26, 05:35 UTC2h 35m
2026-07-26 UAL1943 ORD → CHS Jul 26, 00:15 UTCJul 26, 01:25 UTC1h 10m
2026-07-25 UAL2327 ORD → SFO Jul 25, 22:00 UTCJul 25, 22:55 UTC55m
2026-07-25 UAL645 LAX → EWR Jul 25, 17:05 UTCJul 25, 20:15 UTC3h 10m
2026-07-25 UAL683 DEN → EWR Jul 25, 13:25 UTCJul 25, 15:30 UTC2h 5m
2026-07-24 UAL1373 ORD → DCA Jul 24, 23:55 UTCJul 25, 02:30 UTC2h 35m
2026-07-24 UAL1360 IAD → RSW Jul 24, 20:10 UTCJul 24, 22:00 UTC1h 50m
2026-07-24 UAL1488 IAD → BTV Jul 24, 16:30 UTCJul 24, 18:25 UTC1h 55m
2026-07-24 UAL544 LAX → SFO Jul 24, 12:40 UTCJul 24, 15:00 UTC2h 20m
2026-07-23 UAL401 LIR → IAH Jul 23, 22:35 UTCJul 24, 00:55 UTC2h 20m
2026-07-23 UAL1737 LAX → AUS Jul 23, 17:25 UTCJul 23, 19:45 UTC2h 20m
2026-07-23 UAL1737 LAX → AUS Jul 23, 17:22 UTCJul 23, 20:35 UTC3h 13m
2026-07-23 UAL1318 EWR → MSY Jul 23, 13:25 UTCJul 23, 15:40 UTC2h 15m
2026-07-23 UAL1236 EWR → PHX Jul 23, 06:00 UTCJul 23, 07:25 UTC1h 25m
2026-07-23 UAL1787 SFO → DEN Jul 23, 01:25 UTCJul 23, 03:40 UTC2h 15m
2026-07-22 UAL2455 EWR → ATL Jul 22, 19:46 UTCJul 22, 21:39 UTC1h 53m
2026-07-22 UAL2455 EWR → ATL Jul 22, 19:30 UTCJul 22, 21:45 UTC2h 15m
2026-07-22 UAL347 PHL → DEN Jul 22, 16:10 UTCJul 22, 18:00 UTC1h 50m
2026-07-22 UAL719 MIA → EWR Jul 22, 02:20 UTCJul 22, 04:00 UTC1h 40m
2026-07-21 UAL2660 TPA → EWR Jul 21, 20:50 UTCJul 21, 23:55 UTC3h 5m
2026-07-21 UAL1049 CUN → EWR Jul 21, 16:25 UTCJul 21, 19:05 UTC2h 40m
2026-07-20 UAL586 SJC → DEN Jul 20, 15:55 UTCJul 20, 18:10 UTC2h 15m
2026-07-20 UAL2745 HNL → SFO Jul 20, 03:10 UTCJul 20, 05:05 UTC1h 55m
2026-07-19 UAL475 EWR → MCO Jul 19, 23:05 UTCJul 20, 01:20 UTC2h 15m
2026-07-19 UAL1816 YYC → YEG Jul 19, 20:39 UTCJul 19, 21:06 UTC27m
2026-07-19 UAL1816 - Jul 19, 20:45 UTCJul 19, 21:10 UTC25m
2026-07-19 UAL1816 DEN → YYC Jul 19, 01:55 UTCJul 19, 05:10 UTC3h 15m
2026-07-18 UAL2660 SAV → DEN Jul 18, 21:20 UTCJul 19, 00:20 UTC3h 0m
2026-07-18 UAL1049 DEN → SAV Jul 18, 16:50 UTCJul 18, 19:50 UTC3h 0m
2026-07-18 UAL1561 - Jul 18, 13:50 UTCJul 18, 15:20 UTC1h 30m
2026-07-18 UAL696 - Jul 18, 02:25 UTCJul 18, 04:20 UTC1h 56m
2026-07-18 UAL478 - Jul 18, 00:04 UTCJul 18, 01:10 UTC1h 5m
2026-07-17 UAL703 - Jul 17, 18:50 UTCJul 17, 19:49 UTC1h 0m
2026-07-17 UAL1537 - Jul 17, 14:04 UTCJul 17, 17:30 UTC3h 25m
2026-07-17 UAL1510 DEN → PHL Jul 17, 00:25 UTCJul 17, 03:25 UTC3h 0m
2026-07-16 UAL479 - Jul 16, 19:45 UTCJul 16, 22:05 UTC2h 20m
2026-07-16 UAL1978 DEN → CVG Jul 16, 16:05 UTCJul 16, 18:19 UTC2h 15m
2026-07-16 UAL2754 - Jul 16, 12:14 UTCJul 16, 14:20 UTC2h 5m
2026-07-16 UAL2754 MRY → DEN Jul 16, 12:10 UTCJul 16, 14:15 UTC2h 5m
2026-07-16 UAL1371 - Jul 16, 01:55 UTCJul 16, 03:55 UTC2h 0m
2026-07-15 UAL513 DEN → DEN Jul 15, 20:05 UTCJul 15, 23:55 UTC3h 50m
2026-07-15 UAL1537 PHL → DEN Jul 15, 14:00 UTCJul 15, 17:25 UTC3h 25m
2026-07-15 UAL1510 DEN → PHL Jul 15, 00:55 UTCJul 15, 04:10 UTC3h 15m
2026-07-14 UAL1303 DFW → DEN Jul 14, 22:05 UTCJul 14, 23:45 UTC1h 39m
2026-07-14 UAL2290 ORD → DFW Jul 14, 18:25 UTCJul 14, 20:10 UTC1h 45m
2026-07-14 UAL1310 LGA → ORD Jul 14, 14:38 UTCJul 14, 16:05 UTC1h 27m
2026-07-14 UAL1310 LGA → ORD Jul 14, 14:20 UTCJul 14, 16:10 UTC1h 50m
2026-07-14 UAL2617 ORD → LGA Jul 14, 11:10 UTCJul 14, 12:55 UTC1h 45m

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 N33289 page for operator, model, and routing details .

Mode-S A3A0CF frequently asked

What is Mode-S code A3A0CF?
A3A0CF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N33289.
Where is Mode-S A3A0CF registered?
Mode-S code A3A0CF 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 A3A0CF broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 21:05 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A3A0CF, octal 50720317, decimal 10,723,535.
What flights does A3A0CF operate?
Mode-S A3A0CF has broadcast 20 distinct callsigns, including UAL694, UAL645, UAL2446, UAL248, UAL2455.