sensors Mode-S transponder

A0A903

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N14118 · BOEING 757-200 · operated by UNITED AIRLINES INC

Hex
A0A903
Octal
50124403
Decimal
10,529,027
Country
US
Tail
N14118
Type
B752
No current signal · last broadcast 1h ago
Flights observed
246
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S A0A903.

Country allocation

The ICAO 24-bit address A0A903 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
UAL271 United Airlines 8 2026-06-29
UAL270 - 8 2026-06-29
UAL2191 United Airlines 8 2026-05-27
UAL1981 United Airlines 7 2026-05-18
UAL1095 - 6 2026-07-09
UAL634 United Airlines 5 2026-06-26
UAL37 United Airlines 5 2026-06-09
UAL36 United Airlines 5 2026-06-09
UAL336 - 5 2026-07-08
UAL332 United Airlines 5 2026-05-08
UAL310 United Airlines 5 2026-06-13
UAL2743 United Airlines 5 2026-05-03
UAL2445 United Airlines 5 2026-05-24
UAL2359 United Airlines 5 2026-05-06
UAL2115 - 5 2026-07-08
UAL1626 United Airlines 5 2026-04-26
UAL1597 - 5 2026-07-09
UAL1340 United Airlines 5 2026-04-20
UAL979 - 4 2026-06-15
UAL978 - 4 2026-06-16

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-13 UAL2626 SFO → EWR Jul 13, 23:40 UTCJul 14, 04:45 UTC5h 5m
2026-07-13 UAL1343 - Jul 13, 16:45 UTCJul 13, 21:55 UTC5h 10m
2026-07-09 UAL1597 SFO → EWR Jul 9, 22:15 UTCJul 10, 03:00 UTC4h 45m
2026-07-09 UAL1095 - Jul 9, 12:25 UTCJul 9, 17:30 UTC5h 5m
2026-07-08 UAL336 SFO → IAD Jul 8, 18:20 UTCJul 8, 22:50 UTC4h 30m
2026-07-08 UAL2115 - Jul 8, 10:20 UTCJul 8, 15:45 UTC5h 25m
2026-07-07 UAL316 DUB → EWR Jul 7, 14:11 UTCJul 7, 20:50 UTC6h 39m
2026-07-07 UAL317 EWR → DUB Jul 7, 06:00 UTCJul 7, 11:55 UTC5h 55m
2026-07-06 UAL1700 - Jul 6, 23:35 UTCJul 7, 04:15 UTC4h 40m
2026-07-06 UAL2679 DEN → ORD Jul 6, 16:50 UTCJul 6, 21:45 UTC4h 55m
2026-07-06 UAL887 - Jul 6, 05:45 UTCJul 6, 13:20 UTC7h 35m
2026-07-06 UAL887 LIM → EWR Jul 6, 05:28 UTCJul 6, 13:07 UTC7h 39m
2026-07-05 UAL886 EWR → LIM Jul 5, 20:00 UTCJul 5, 23:55 UTC3h 55m
2026-07-05 UAL886 EWR → LIM Jul 5, 19:53 UTCJul 6, 03:14 UTC7h 21m
2026-07-05 UAL1597 - Jul 5, 05:55 UTCJul 5, 06:25 UTC30m
2026-07-05 UAL1597 BDL → EWR Jul 5, 06:07 UTCJul 5, 06:26 UTC19m
2026-07-04 UAL1597 SFO → BDL Jul 4, 20:10 UTCJul 5, 03:15 UTC7h 5m
2026-07-04 UAL1777 - Jul 4, 12:20 UTCJul 4, 18:05 UTC5h 45m
2026-07-04 UAL2248 SFO → EWR Jul 4, 02:20 UTCJul 4, 07:20 UTC5h 0m
2026-07-03 - SFO → SFO Jul 3, 14:25 UTCJul 3, 14:30 UTC5m
2026-07-01 UAL1558 - Jul 1, 01:15 UTCJul 1, 06:40 UTC5h 25m
2026-07-01 UAL1558 EWR → SFO Jul 1, 01:08 UTCJul 1, 06:36 UTC5h 28m
2026-06-30 UAL419 SFO → EWR Jun 30, 13:25 UTCJun 30, 18:25 UTC5h 0m
2026-06-29 UAL2080 - Jun 29, 22:55 UTCJun 30, 04:40 UTC5h 46m
2026-06-29 UAL271 ATL → EWR Jun 29, 11:39 UTCJun 29, 18:19 UTC6h 40m
2026-06-29 UAL271 ATL → EWR Jun 29, 11:42 UTCJun 29, 18:20 UTC6h 38m
2026-06-29 UAL270 - Jun 29, 03:25 UTCJun 29, 04:45 UTC1h 20m
2026-06-29 UAL270 EWR → SNN Jun 29, 03:12 UTCJun 29, 09:14 UTC6h 2m
2026-06-28 UAL1597 SFO → EWR Jun 28, 20:04 UTCJun 29, 00:54 UTC4h 50m
2026-06-28 UAL1777 - Jun 28, 12:29 UTCJun 28, 18:19 UTC5h 50m
2026-06-28 UAL698 SFO → EWR Jun 28, 04:35 UTCJun 28, 09:15 UTC4h 40m
2026-06-27 UAL648 EWR → SFO Jun 27, 14:54 UTCJun 27, 20:24 UTC5h 30m
2026-06-27 UAL327 - Jun 27, 05:35 UTCJun 27, 10:00 UTC4h 25m
2026-06-26 UAL210 EWR → SAN Jun 26, 22:34 UTCJun 27, 04:00 UTC5h 25m
2026-06-26 UAL634 ORD → CMH Jun 26, 12:39 UTCJun 26, 14:09 UTC1h 30m
2026-06-26 UAL634 ORD → CMH Jun 26, 12:34 UTCJun 26, 20:29 UTC7h 55m
2026-06-26 UAL633 - Jun 26, 02:40 UTCJun 26, 08:50 UTC6h 10m
2026-06-25 UAL2227 - Jun 25, 19:59 UTCJun 26, 00:35 UTC4h 35m
2026-06-25 UAL2434 - Jun 25, 10:30 UTCJun 25, 15:44 UTC5h 15m
2026-06-25 UAL3907 SFO → EWR Jun 25, 02:19 UTCJun 25, 06:55 UTC4h 35m
2026-06-24 UAL1343 - Jun 24, 19:00 UTCJun 25, 00:44 UTC5h 45m
2026-06-24 UAL239 OPO → EWR Jun 24, 08:20 UTCJun 24, 15:36 UTC7h 16m
2026-06-24 UAL239 OPO → EWR Jun 24, 08:14 UTCJun 24, 15:39 UTC7h 25m
2026-06-23 UAL238 EWR → OPO Jun 23, 23:55 UTCJun 24, 05:59 UTC6h 5m
2026-06-23 UAL238 EWR → OPO Jun 23, 22:38 UTCJun 24, 05:55 UTC7h 17m
2026-06-23 UAL1149 EWR → SRQ Jun 23, 14:15 UTCJun 23, 18:45 UTC4h 30m
2026-06-23 UAL1149 EWR → SRQ Jun 23, 14:18 UTCJun 23, 19:17 UTC4h 59m
2026-06-23 UAL1558 - Jun 23, 00:45 UTCJun 23, 06:49 UTC6h 5m
2026-06-22 UAL419 SFO → EWR Jun 22, 13:10 UTCJun 22, 17:50 UTC4h 40m
2026-06-22 UAL1558 - Jun 22, 00:55 UTCJun 22, 06:39 UTC5h 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 N14118 page for operator, model, and routing details .

Mode-S A0A903 frequently asked

What is Mode-S code A0A903?
A0A903 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N14118.
Where is Mode-S A0A903 registered?
Mode-S code A0A903 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 A0A903 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 A0A903, octal 50124403, decimal 10,529,027.
What flights does A0A903 operate?
Mode-S A0A903 has broadcast 20 distinct callsigns, including UAL271, UAL270, UAL2191, UAL1981, UAL1095.