sensors Mode-S transponder

A2F9DD

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N291GX · AIRBUS A-320 · operated by UMB BANK NA TRUSTEE

Hex
A2F9DD
Octal
50574735
Decimal
10,680,797
Country
US
Tail
N291GX
Type
A320
No current signal · last broadcast 1d ago
Flights observed
5
Distinct callsigns
4
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A2F9DD.

Country allocation

The ICAO 24-bit address A2F9DD 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 4 distinct

Callsign Airline Flights Last seen
GXA611 - 2 2026-04-13
GXA614 Grixona 1 2026-04-12
GXA613 - 1 2026-04-13
GXA612 - 1 2026-04-13

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-13 GXA611 - Apr 13, 21:40 UTCApr 13, 22:05 UTC25m
2026-04-13 GXA612 - Apr 13, 16:30 UTCApr 13, 17:05 UTC35m
2026-04-13 GXA613 - Apr 13, 11:20 UTCApr 13, 11:40 UTC20m
2026-04-12 GXA614 BZN → BED Apr 12, 23:55 UTCApr 13, 00:25 UTC30m
2026-04-12 GXA611 - Apr 12, 19:50 UTCApr 12, 20:15 UTC25m

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 N291GX page for operator, model, and routing details .

Mode-S A2F9DD frequently asked

What is Mode-S code A2F9DD?
A2F9DD is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N291GX.
Where is Mode-S A2F9DD registered?
Mode-S code A2F9DD 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 A2F9DD broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A2F9DD, octal 50574735, decimal 10,680,797.
What flights does A2F9DD operate?
Mode-S A2F9DD has broadcast 4 distinct callsigns, including GXA611, GXA614, GXA613, GXA612.