sensors Mode-S transponder

A275B8

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N258FE · operated by FEDERAL EXPRESS CORP

Hex
A275B8
Octal
50472670
Decimal
10,646,968
Country
US
Tail
N258FE
Type
B763
Broadcasting now · callsign FDX540 · 20,100 ft
Flights observed
3
Distinct callsigns
2
Country
US
Last broadcast
15h ago

Current position

A275B8 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A275B8 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 2 distinct

Callsign Airline Flights Last seen
FDX1876 - 2 2026-04-14
FDX1801 FedEx Express 1 2026-04-14

Recent flights last 3

DateFlightRouteTakeoffLandingDuration
2026-04-14 FDX1876 - Apr 14, 09:10 UTCApr 14, 09:40 UTC30m
2026-04-14 FDX1876 - Apr 14, 08:50 UTCApr 14, 09:05 UTC15m
2026-04-14 FDX1801 LAX → OAK Apr 14, 05:15 UTCApr 14, 05:30 UTC15m

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 N258FE page for operator, model, and routing details .

Mode-S A275B8 frequently asked

What is Mode-S code A275B8?
A275B8 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N258FE.
Where is Mode-S A275B8 registered?
Mode-S code A275B8 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 A275B8 broadcasting right now?
Yes. Mode-S A275B8 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A275B8, octal 50472670, decimal 10,646,968.
What flights does A275B8 operate?
Mode-S A275B8 has broadcast 2 distinct callsigns, including FDX1876, FDX1801.