Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A1242D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N17289 · operated by UNITED AIRLINES INC

Hex
A1242D
Octal
50222055
Decimal
10,560,557
Country
US
Tail
N17289
Type
B38M
No current signal · last broadcast 1h ago
Flights observed
288
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S A1242D.

Country allocation

The ICAO 24-bit address A1242D 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
UAL1900 United Airlines 6 2026-05-25
UAL1129 United Airlines 5 2026-04-18
UAL560 United Airlines 4 2026-04-17
UAL2467 - 4 2026-04-17
UAL1880 United Airlines 4 2026-05-23
UAL280 United Airlines 3 2026-05-21
UAL258 United Airlines 3 2026-05-12
UAL2185 United Airlines 3 2026-04-21
UAL1832 United Airlines 3 2026-06-08
UAL1629 United Airlines 3 2026-04-14
UAL1562 United Airlines 3 2026-05-23
UAL1419 United Airlines 3 2026-04-13
UAL1111 United Airlines 3 2026-05-15
UAL1009 United Airlines 3 2026-06-03
UAL8223 United Airlines 2 2026-05-06
UAL8217 United Airlines 2 2026-06-08
UAL8168 United Airlines 2 2026-06-01
UAL8120 United Airlines 2 2026-05-24
UAL781 United Airlines 2 2026-05-09
UAL663 United Airlines 2 2026-04-21

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-06-12 UAL2230 ORD → DFW Jun 12, 21:40 UTCJun 13, 00:00 UTC2h 20m
2026-06-12 UAL2231 MEM → EWR Jun 12, 17:25 UTCJun 12, 19:30 UTC2h 5m
2026-06-12 UAL1901 GUA → IAH Jun 12, 14:55 UTCJun 12, 15:25 UTC30m
2026-06-12 UAL1901 GUA → IAH Jun 12, 12:55 UTCJun 12, 13:10 UTC15m
2026-06-12 UAL1137 LAX → GUA Jun 12, 06:20 UTCJun 12, 11:25 UTC5h 5m
2026-06-12 UAL418 SAN → SFO Jun 12, 03:15 UTCJun 12, 04:00 UTC45m
2026-06-11 UAL417 LAX → OGG Jun 11, 16:15 UTCJun 11, 16:40 UTC25m
2026-06-11 UAL417 LAX → OGG Jun 11, 16:18 UTCJun 11, 21:16 UTC4h 58m
2026-06-11 UAL1756 LAS → EWR Jun 11, 13:15 UTCJun 11, 13:50 UTC35m
2026-06-11 UAL2432 SFO → LAS Jun 11, 02:20 UTCJun 11, 02:50 UTC30m
2026-06-11 UAL2432 SFO → LAS Jun 11, 02:28 UTCJun 11, 02:58 UTC30m
2026-06-10 UAL2681 DEN → SFO Jun 10, 22:05 UTCJun 11, 00:30 UTC2h 25m
2026-06-10 UAL8135 CLE → YYZ Jun 10, 18:15 UTCJun 10, 20:50 UTC2h 35m
2026-06-10 UAL2704 SFO → HNL Jun 10, 11:30 UTCJun 10, 15:55 UTC4h 25m
2026-06-10 UAL2704 SFO → HNL Jun 10, 11:28 UTCJun 10, 15:51 UTC4h 23m
2026-06-09 UAL2476 SAN → DEN Jun 9, 20:20 UTCJun 9, 22:35 UTC2h 15m
2026-06-09 UAL2246 RSW → EWR Jun 9, 15:25 UTCJun 9, 18:05 UTC2h 40m
2026-06-09 UAL1833 MCO → EWR Jun 9, 12:40 UTCJun 9, 13:40 UTC1h 0m
2026-06-08 UAL8217 SAV → ORD Jun 8, 22:35 UTCJun 9, 01:05 UTC2h 30m
2026-06-08 UAL8217 SAV → ORD Jun 8, 22:38 UTCJun 9, 01:03 UTC2h 25m
2026-06-08 UAL1832 CUN → IAH Jun 8, 18:43 UTCJun 8, 21:18 UTC2h 35m
2026-06-08 UAL1832 CUN → IAH Jun 8, 19:05 UTCJun 8, 21:25 UTC2h 20m
2026-06-08 UAL221 SFO → MCO Jun 8, 08:30 UTCJun 8, 15:50 UTC7h 20m
2026-06-08 UAL222 IAD → SFO Jun 8, 00:48 UTCJun 8, 06:53 UTC6h 5m
2026-06-08 UAL222 IAD → SFO Jun 8, 00:50 UTCJun 8, 06:55 UTC6h 5m
2026-06-07 UAL1784 STT → EWR Jun 7, 17:15 UTCJun 7, 21:45 UTC4h 30m
2026-06-07 UAL1139 EWR → PBI Jun 7, 10:45 UTCJun 7, 15:40 UTC4h 55m
2026-06-06 UAL1386 LAS → EWR Jun 6, 23:24 UTCJun 7, 03:45 UTC4h 20m
2026-06-06 UAL1864 DEN → IAH Jun 6, 16:39 UTCJun 6, 21:25 UTC4h 45m
2026-06-06 UAL1999 SFO → DEN Jun 6, 10:14 UTCJun 6, 12:45 UTC2h 30m
2026-06-05 UAL435 KOA → SFO Jun 5, 23:35 UTCJun 6, 02:00 UTC2h 25m
2026-06-05 UAL1784 STT → EWR Jun 5, 17:20 UTCJun 5, 21:45 UTC4h 25m
2026-06-05 UAL1139 EWR → PBI Jun 5, 10:45 UTCJun 5, 15:45 UTC5h 0m
2026-06-04 UAL1827 MCO → EWR Jun 4, 23:05 UTCJun 5, 04:00 UTC4h 55m
2026-06-04 UAL2399 MCO → IAH Jun 4, 18:55 UTCJun 4, 21:40 UTC2h 45m
2026-06-04 UAL2105 SAT → IAH Jun 4, 16:15 UTCJun 4, 17:30 UTC1h 15m
2026-06-04 UAL491 BZN → DEN Jun 4, 13:15 UTCJun 4, 14:00 UTC45m
2026-06-04 UAL1326 SFO → BNA Jun 4, 02:10 UTCJun 4, 02:45 UTC35m
2026-06-03 UAL2270 LAS → IAH Jun 3, 20:07 UTCJun 3, 21:40 UTC1h 33m
2026-06-03 UAL2270 LAS → IAH Jun 3, 19:50 UTCJun 3, 21:45 UTC1h 55m
2026-06-03 UAL779 BOS → IAH Jun 3, 16:40 UTCJun 3, 18:20 UTC1h 40m
2026-06-03 UAL1336 SNA → IAH Jun 3, 12:40 UTCJun 3, 14:50 UTC2h 10m
2026-06-03 UAL1009 EWR → MCO Jun 3, 01:10 UTCJun 3, 01:15 UTC5m
2026-06-02 UAL1009 EWR → MCO Jun 2, 21:30 UTCJun 3, 01:15 UTC3h 45m
2026-06-02 UAL1009 EWR → MCO Jun 2, 21:10 UTCJun 3, 00:54 UTC3h 44m
2026-06-02 UAL1008 BOS → SFO Jun 2, 14:30 UTCJun 2, 18:35 UTC4h 5m
2026-06-02 UAL2389 LGA → ORD Jun 2, 10:10 UTCJun 2, 11:55 UTC1h 45m
2026-06-01 UAL8168 IAH → STL Jun 1, 23:20 UTCJun 2, 02:30 UTC3h 10m
2026-06-01 UAL8168 IAH → STL Jun 1, 22:56 UTCJun 2, 02:26 UTC3h 30m
2026-06-01 UAL708 DEN → SFO Jun 1, 19:15 UTCJun 1, 21:30 UTC2h 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 N17289 page for operator, model, and routing details .

Mode-S A1242D frequently asked

What is Mode-S code A1242D?
A1242D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N17289.
Where is Mode-S A1242D registered?
Mode-S code A1242D 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 A1242D broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A1242D, octal 50222055, decimal 10,560,557.
What flights does A1242D operate?
Mode-S A1242D has broadcast 20 distinct callsigns, including UAL1900, UAL1129, UAL560, UAL2467, UAL1880.