sensors Mode-S transponder

A5277D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N431GT · operated by ATLAS AIR INC

Hex
A5277D
Octal
51223575
Decimal
10,823,549
Country
US
Tail
N431GT
Type
B744
Broadcasting now · callsign GTI8905 · 7,775 ft
Flights observed
4
Distinct callsigns
1
Country
US
Last broadcast
18h ago

Current position

A5277D is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A5277D 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 1 distinct

Callsign Airline Flights Last seen
GTI8692 Atlas Air 4 2026-04-14

Recent flights last 4

DateFlightRouteTakeoffLandingDuration
2026-04-14 GTI8692 ANC → GDL Apr 14, 05:15 UTCApr 14, 06:45 UTC1h 30m
2026-04-13 GTI8692 ANC → GDL Apr 13, 21:15 UTCApr 13, 22:55 UTC1h 40m
2026-04-13 GTI8692 ANC → GDL Apr 13, 16:15 UTCApr 13, 17:20 UTC1h 5m
2026-04-13 GTI8692 ANC → GDL Apr 13, 13:50 UTCApr 13, 16:15 UTC2h 25m

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 N431GT page for operator, model, and routing details .

Mode-S A5277D frequently asked

What is Mode-S code A5277D?
A5277D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N431GT.
Where is Mode-S A5277D registered?
Mode-S code A5277D 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 A5277D broadcasting right now?
Yes. Mode-S A5277D is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A5277D, octal 51223575, decimal 10,823,549.
What flights does A5277D operate?
Mode-S A5277D has broadcast 1 distinct callsign, including GTI8692.