Apparatus

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sensors Mode-S transponder

A55017

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N441UA · AIRBUS A-320 · operated by UNITED AIRLINES INC

Hex
A55017
Octal
51250027
Decimal
10,833,943
Country
US
Tail
N441UA
Type
A320
No current signal · last broadcast Jul 25, 03:40 UTC
Flights observed
460
Distinct callsigns
20
Country
US
Last broadcast
Jul 25, 03:40 UTC

Last known position

Most recent position reported by Mode-S A55017.

Country allocation

The ICAO 24-bit address A55017 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
UAL1178 - 7 2026-07-18
UAL2225 - 5 2026-07-05
UAL2160 United Airlines 5 2026-05-28
UAL2847 United Airlines 4 2026-06-16
UAL2479 United Airlines 4 2026-07-20
UAL246 United Airlines 4 2026-05-20
UAL2228 United Airlines 4 2026-05-21
UAL2193 United Airlines 4 2026-05-30
UAL2174 - 4 2026-07-12
UAL2149 United Airlines 4 2026-06-28
UAL2105 United Airlines 4 2026-05-03
UAL1934 - 4 2026-07-12
UAL1673 - 4 2026-07-14
UAL1655 - 4 2026-07-18
UAL1564 - 4 2026-07-19
UAL1366 - 4 2026-07-12
UAL1326 - 4 2026-07-09
UAL1082 United Airlines 4 2026-04-22
UAL600 - 3 2026-07-05
UAL491 United Airlines 3 2026-05-03

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-25 UAL1225 ONT → SFO Jul 25, 02:20 UTCJul 25, 03:35 UTC1h 15m
2026-07-24 UAL8104 YUL → YFC Jul 24, 22:35 UTCJul 25, 00:25 UTC1h 50m
2026-07-24 UAL8104 YUL → YFC Jul 24, 22:31 UTCJul 25, 00:24 UTC1h 53m
2026-07-24 UAL1007 ORD → ALB Jul 24, 19:00 UTCJul 24, 20:50 UTC1h 50m
2026-07-24 UAL2625 PHX → EWR Jul 24, 16:05 UTCJul 24, 17:55 UTC1h 50m
2026-07-24 UAL333 BOS → LAX Jul 24, 02:35 UTCJul 24, 14:45 UTC12h 10m
2026-07-23 UAL513 DEN → PHL Jul 23, 20:05 UTCJul 24, 01:20 UTC5h 15m
2026-07-23 UAL2004 ORD → SFO Jul 23, 16:50 UTCJul 23, 17:55 UTC1h 5m
2026-07-23 UAL497 CVG → DEN Jul 23, 14:25 UTCJul 23, 15:30 UTC1h 5m
2026-07-23 UAL2041 SFO → SAN Jul 23, 10:50 UTCJul 23, 12:25 UTC1h 35m
2026-07-23 UAL2076 LAS → SFO Jul 23, 00:50 UTCJul 23, 02:15 UTC1h 25m
2026-07-22 UAL1305 EWR → RDU Jul 22, 18:50 UTCJul 22, 20:35 UTC1h 45m
2026-07-22 UAL397 DEN → MSP Jul 22, 15:50 UTCJul 22, 17:20 UTC1h 30m
2026-07-22 UAL1003 - Jul 22, 13:50 UTCJul 22, 14:25 UTC35m
2026-07-22 UAL1483 LAS → SFO Jul 22, 01:35 UTCJul 22, 02:05 UTC30m
2026-07-21 UAL531 EWR → PBI Jul 21, 22:45 UTCJul 21, 23:40 UTC55m
2026-07-21 UAL1537 - Jul 21, 20:05 UTCJul 21, 20:45 UTC40m
2026-07-21 UAL489 - Jul 21, 16:05 UTCJul 21, 18:00 UTC1h 55m
2026-07-21 UAL1704 EWR → MSP Jul 21, 01:30 UTCJul 21, 03:25 UTC1h 55m
2026-07-20 UAL2479 ORD → LAS Jul 20, 21:50 UTCJul 20, 23:35 UTC1h 45m
2026-07-20 UAL1819 - Jul 20, 20:00 UTCJul 20, 20:30 UTC30m
2026-07-20 UAL1747 - Jul 20, 17:45 UTCJul 20, 18:20 UTC35m
2026-07-20 UAL1747 AUS → IAH Jul 20, 17:32 UTCJul 20, 18:19 UTC47m
2026-07-20 UAL1823 SFO → DEN Jul 20, 15:30 UTCJul 20, 16:00 UTC30m
2026-07-20 UAL1345 YYZ → IAH Jul 20, 10:35 UTCJul 20, 13:20 UTC2h 45m
2026-07-19 UAL313 BOI → SFO Jul 19, 23:55 UTCJul 20, 02:50 UTC2h 55m
2026-07-19 UAL2682 - Jul 19, 21:30 UTCJul 19, 22:15 UTC45m
2026-07-19 UAL2682 DFW → IAH Jul 19, 21:23 UTCJul 19, 22:09 UTC46m
2026-07-19 UAL1564 IAD → DFW Jul 19, 17:45 UTCJul 19, 20:15 UTC2h 30m
2026-07-19 UAL1535 - Jul 19, 15:35 UTCJul 19, 16:15 UTC40m
2026-07-19 UAL529 IAD → RDU Jul 19, 13:55 UTCJul 19, 14:30 UTC35m
2026-07-19 UAL8116 SFO → EWR Jul 19, 01:05 UTCJul 19, 02:35 UTC1h 30m
2026-07-19 UAL8116 SFO → EWR Jul 19, 01:12 UTCJul 19, 02:42 UTC1h 30m
2026-07-18 UAL1655 - Jul 18, 18:55 UTCJul 18, 21:40 UTC2h 45m
2026-07-18 UAL764 - Jul 18, 14:45 UTCJul 18, 17:45 UTC3h 0m
2026-07-18 UAL2137 - Jul 18, 11:25 UTCJul 18, 12:00 UTC35m
2026-07-18 UAL1178 - Jul 18, 02:09 UTCJul 18, 02:40 UTC30m
2026-07-17 UAL739 - Jul 17, 23:00 UTCJul 18, 00:10 UTC1h 10m
2026-07-17 UAL739 OMA → ORD Jul 17, 23:01 UTCJul 17, 23:55 UTC54m
2026-07-17 UAL247 DTW → ORD Jul 17, 18:55 UTCJul 17, 20:04 UTC1h 10m
2026-07-17 UAL1660 - Jul 17, 15:49 UTCJul 17, 16:24 UTC35m
2026-07-17 UAL2093 - Jul 17, 14:04 UTCJul 17, 14:35 UTC30m
2026-07-17 UAL2093 ORD → MSN Jul 17, 14:10 UTCJul 17, 14:32 UTC22m
2026-07-15 UAL1744 - Jul 15, 18:15 UTCJul 16, 01:15 UTC7h 0m
2026-07-15 UAL704 - Jul 15, 14:50 UTCJul 15, 16:15 UTC1h 25m
2026-07-15 UAL1269 ORD → BWI Jul 15, 11:54 UTCJul 15, 13:14 UTC1h 20m
2026-07-14 UAL658 MSP → ORD Jul 14, 22:20 UTCJul 14, 23:20 UTC59m
2026-07-14 UAL2298 - Jul 14, 19:55 UTCJul 14, 20:50 UTC55m
2026-07-14 UAL2298 ORD → MSP Jul 14, 20:03 UTCJul 14, 20:46 UTC43m
2026-07-14 UAL1114 DFW → ORD Jul 14, 15:20 UTCJul 14, 17:15 UTC1h 55m

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 N441UA page for operator, model, and routing details .

Mode-S A55017 frequently asked

What is Mode-S code A55017?
A55017 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N441UA.
Where is Mode-S A55017 registered?
Mode-S code A55017 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 A55017 broadcasting right now?
No active broadcast right now. Last signal was Jul 25, 03:40 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A55017, octal 51250027, decimal 10,833,943.
What flights does A55017 operate?
Mode-S A55017 has broadcast 20 distinct callsigns, including UAL1178, UAL2225, UAL2160, UAL2847, UAL2479.