Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A0B81E

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N14531 · AIRBUS A-321neo · operated by UNITED AIRLINES INC

Hex
A0B81E
Octal
50134036
Decimal
10,532,894
Country
US
Tail
N14531
Type
A21N
No current signal · last broadcast Jul 26, 14:25 UTC
Flights observed
425
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 14:25 UTC

Last known position

Most recent position reported by Mode-S A0B81E.

Country allocation

The ICAO 24-bit address A0B81E 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
UAL789 United Airlines 9 2026-07-25
UAL746 United Airlines 5 2026-07-25
UAL706 - 5 2026-06-14
UAL695 United Airlines 5 2026-06-11
UAL526 United Airlines 5 2026-06-16
UAL2481 United Airlines 5 2026-06-08
UAL2446 - 5 2026-07-08
UAL2089 United Airlines 5 2026-06-11
UAL1323 United Airlines 5 2026-06-16
UAL580 - 4 2026-07-15
UAL475 United Airlines 4 2026-05-22
UAL341 - 4 2026-07-17
UAL2618 United Airlines 4 2026-06-10
UAL2440 - 4 2026-06-25
UAL2354 - 4 2026-06-30
UAL2278 United Airlines 4 2026-04-21
UAL2179 - 4 2026-07-08
UAL2106 United Airlines 4 2026-05-13
UAL1974 - 4 2026-07-13
UAL1479 - 4 2026-07-08

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL459 ORD → LAS Jul 26, 12:10 UTCJul 26, 14:15 UTC2h 5m
2026-07-26 UAL498 PDX → EWR Jul 26, 02:00 UTCJul 26, 04:10 UTC2h 10m
2026-07-25 UAL746 SRQ → EWR Jul 25, 20:25 UTCJul 25, 23:45 UTC3h 20m
2026-07-25 UAL789 EWR → CLT Jul 25, 15:51 UTCJul 25, 18:32 UTC2h 41m
2026-07-25 UAL789 EWR → CLT Jul 25, 15:45 UTCJul 25, 18:35 UTC2h 50m
2026-07-25 UAL1889 SFO → IND Jul 25, 12:12 UTCJul 25, 13:54 UTC1h 42m
2026-07-25 UAL1889 SFO → IND Jul 25, 12:05 UTCJul 25, 14:00 UTC1h 55m
2026-07-25 UAL2132 MSP → EWR Jul 25, 02:10 UTCJul 25, 04:15 UTC2h 5m
2026-07-24 UAL746 SRQ → EWR Jul 24, 20:30 UTCJul 24, 23:50 UTC3h 20m
2026-07-24 UAL789 EWR → CLT Jul 24, 15:50 UTCJul 24, 18:40 UTC2h 50m
2026-07-24 UAL789 EWR → CLT Jul 24, 15:51 UTCJul 24, 18:36 UTC2h 45m
2026-07-24 UAL2643 DEN → BOS Jul 24, 11:40 UTCJul 24, 13:30 UTC1h 50m
2026-07-24 UAL3882 FTW → SFO Jul 24, 05:25 UTCJul 24, 07:15 UTC1h 50m
2026-07-21 UAL3876 EWR → MLB Jul 21, 03:05 UTCJul 21, 05:05 UTC2h 0m
2026-07-21 UAL3876 EWR → MLB Jul 21, 03:07 UTCJul 21, 05:04 UTC1h 57m
2026-07-20 UAL1715 DEN → EWR Jul 20, 22:55 UTCJul 21, 02:05 UTC3h 9m
2026-07-20 UAL1999 EWR → DEN Jul 20, 16:20 UTCJul 20, 19:50 UTC3h 30m
2026-07-20 UAL563 SNA → SFO Jul 20, 12:35 UTCJul 20, 14:10 UTC1h 35m
2026-07-20 UAL2085 EWR → AUS Jul 20, 02:00 UTCJul 20, 03:55 UTC1h 55m
2026-07-19 UAL8129 DTW → YYZ Jul 19, 19:40 UTCJul 19, 23:15 UTC3h 35m
2026-07-19 UAL8129 DTW → YYZ Jul 19, 19:39 UTCJul 19, 23:12 UTC3h 33m
2026-07-19 UAL1442 DEN → LGA Jul 19, 14:20 UTCJul 19, 17:35 UTC3h 15m
2026-07-19 UAL1874 - Jul 19, 10:25 UTCJul 19, 12:20 UTC1h 55m
2026-07-18 UAL1585 DEN → IAH Jul 18, 23:48 UTCJul 19, 01:41 UTC1h 53m
2026-07-18 UAL1585 - Jul 18, 23:45 UTCJul 19, 01:40 UTC1h 55m
2026-07-18 UAL1565 SFO → PHX Jul 18, 20:00 UTCJul 18, 21:55 UTC1h 55m
2026-07-18 UAL660T ORD → SAN Jul 18, 14:25 UTCJul 18, 17:56 UTC3h 31m
2026-07-18 UAL660T ORD → SAN Jul 18, 14:35 UTCJul 18, 18:00 UTC3h 25m
2026-07-18 UAL729 - Jul 18, 07:50 UTCJul 18, 11:35 UTC3h 45m
2026-07-18 UAL2499 SEA → SFO Jul 18, 02:22 UTCJul 18, 05:37 UTC3h 15m
2026-07-18 UAL2499 SEA → SFO Jul 18, 02:19 UTCJul 18, 05:45 UTC3h 26m
2026-07-17 UAL2835 SEA → ORD Jul 17, 20:44 UTCJul 18, 00:45 UTC4h 0m
2026-07-17 UAL341 ORD → SEA Jul 17, 12:45 UTCJul 17, 16:29 UTC3h 45m
2026-07-16 UAL1482 - Jul 16, 23:44 UTCJul 17, 03:25 UTC3h 40m
2026-07-16 UAL1812 DEN → SFO Jul 16, 20:00 UTCJul 16, 22:05 UTC2h 5m
2026-07-16 UAL1409 - Jul 16, 15:49 UTCJul 16, 17:40 UTC1h 50m
2026-07-16 UAL1799 ORD → IAH Jul 16, 11:53 UTCJul 16, 13:51 UTC1h 58m
2026-07-16 UAL1799 - Jul 16, 11:40 UTCJul 16, 13:49 UTC2h 10m
2026-07-15 UAL2320 LAS → ORD Jul 15, 23:45 UTCJul 16, 02:50 UTC3h 5m
2026-07-15 UAL777 ORD → LAS Jul 15, 18:00 UTCJul 15, 21:10 UTC3h 10m
2026-07-15 UAL580 - Jul 15, 12:20 UTCJul 15, 16:00 UTC3h 40m
2026-07-15 UAL661T - Jul 15, 03:00 UTCJul 15, 06:25 UTC3h 25m
2026-07-14 UAL2135 - Jul 14, 22:30 UTCJul 15, 00:40 UTC2h 9m
2026-07-14 UAL1448 - Jul 14, 18:00 UTCJul 14, 20:15 UTC2h 15m
2026-07-14 UAL580 - Jul 14, 12:20 UTCJul 14, 16:00 UTC3h 40m
2026-07-14 UAL580 LAX → ORD Jul 14, 12:25 UTCJul 14, 15:54 UTC3h 29m
2026-07-14 UAL661 ORD → LAX Jul 14, 03:03 UTCJul 14, 06:17 UTC3h 14m
2026-07-14 UAL661 - Jul 14, 02:50 UTCJul 14, 06:20 UTC3h 30m
2026-07-13 UAL2135 - Jul 13, 22:35 UTCJul 14, 00:55 UTC2h 20m
2026-07-13 UAL1448 - Jul 13, 17:55 UTCJul 13, 20:30 UTC2h 35m

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 N14531 page for operator, model, and routing details .

Mode-S A0B81E frequently asked

What is Mode-S code A0B81E?
A0B81E is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N14531.
Where is Mode-S A0B81E registered?
Mode-S code A0B81E 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 A0B81E broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 14:25 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A0B81E, octal 50134036, decimal 10,532,894.
What flights does A0B81E operate?
Mode-S A0B81E has broadcast 20 distinct callsigns, including UAL789, UAL746, UAL706, UAL695, UAL526.