sensors Mode-S transponder

A0B7FB

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N14521 · operated by UNITED AIRLINES INC

Hex
A0B7FB
Octal
50133773
Decimal
10,532,859
Country
US
Tail
N14521
Type
A21N
Transponder active on ground
Flights observed
9
Distinct callsigns
6
Country
US
Last broadcast
23h ago

Last known position

Most recent position reported by Mode-S A0B7FB.

Country allocation

The ICAO 24-bit address A0B7FB 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 6 distinct

Callsign Airline Flights Last seen
UAL459 - 2 2026-04-13
UAL1915 - 2 2026-04-13
UAL1834 - 2 2026-04-12
UAL498 - 1 2026-04-13
UAL2633 United Airlines 1 2026-04-13
UAL1246 - 1 2026-04-13

Recent flights last 9

DateFlightRouteTakeoffLandingDuration
2026-04-13 UAL2633 PHL → IAH Apr 13, 23:30 UTCApr 13, 23:40 UTC10m
2026-04-13 UAL1246 - Apr 13, 20:00 UTCApr 13, 20:10 UTC10m
2026-04-13 UAL1915 - Apr 13, 16:15 UTCApr 13, 18:05 UTC1h 50m
2026-04-13 UAL1915 - Apr 13, 16:05 UTCApr 13, 16:15 UTC10m
2026-04-13 UAL459 - Apr 13, 12:20 UTCApr 13, 14:10 UTC1h 50m
2026-04-13 UAL459 - Apr 13, 12:05 UTCApr 13, 12:15 UTC10m
2026-04-13 UAL498 DEN → PDX Apr 13, 01:45 UTCApr 13, 04:00 UTC2h 15m
2026-04-12 UAL1834 - Apr 12, 16:21 UTCApr 12, 18:36 UTC2h 15m
2026-04-12 UAL1834 - Apr 12, 16:21 UTCApr 12, 18:16 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 N14521 page for operator, model, and routing details .

Mode-S A0B7FB frequently asked

What is Mode-S code A0B7FB?
A0B7FB is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N14521.
Where is Mode-S A0B7FB registered?
Mode-S code A0B7FB 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 A0B7FB broadcasting right now?
Mode-S A0B7FB is currently broadcasting from the ground.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A0B7FB, octal 50133773, decimal 10,532,859.
What flights does A0B7FB operate?
Mode-S A0B7FB has broadcast 6 distinct callsigns, including UAL459, UAL1915, UAL1834, UAL498, UAL2633.