sensors Mode-S transponder

A2004D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N228SD · operated by GENERAL ATOMICS AERONAUTICAL SYSTEMS INC

Hex
A2004D
Octal
50400115
Decimal
10,616,909
Country
US
Tail
N228SD
No current signal · last broadcast 5h ago
Flights observed
13
Distinct callsigns
1
Country
US
Last broadcast
5h ago

Last known position

Most recent position reported by Mode-S A2004D.

Country allocation

The ICAO 24-bit address A2004D 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
N228SD - 13 2026-07-14

Recent flights last 13

DateFlightRouteTakeoffLandingDuration
2026-07-14 N228SD - Jul 14, 01:05 UTCJul 14, 01:10 UTC5m
2026-07-13 N228SD - Jul 13, 23:45 UTCJul 14, 00:00 UTC15m
2026-07-13 N228SD - Jul 13, 21:55 UTCJul 13, 22:35 UTC40m
2026-07-10 N228SD - Jul 10, 21:15 UTCJul 10, 21:50 UTC35m
2026-07-10 N228SD - Jul 10, 17:20 UTCJul 10, 17:40 UTC20m
2026-07-07 N228SD - Jul 7, 19:35 UTCJul 7, 19:55 UTC20m
2026-07-06 N228SD - Jul 6, 19:20 UTCJul 6, 19:55 UTC35m
2026-07-06 N228SD - Jul 6, 17:30 UTCJul 6, 17:55 UTC25m
2026-07-01 N228SD - Jul 1, 21:40 UTCJul 1, 22:20 UTC40m
2026-07-01 N228SD MYF → MYF Jul 1, 05:05 UTCJul 1, 05:10 UTC5m
2026-07-01 N228SD - Jul 1, 04:10 UTCJul 1, 05:00 UTC50m
2026-06-25 N228SD MYF → MYF Jun 25, 22:29 UTCJun 25, 22:45 UTC15m
2026-06-25 N228SD - Jun 25, 21:10 UTCJun 25, 21:25 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 N228SD page for operator, model, and routing details .

Mode-S A2004D frequently asked

What is Mode-S code A2004D?
A2004D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N228SD.
Where is Mode-S A2004D registered?
Mode-S code A2004D 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 A2004D broadcasting right now?
No active broadcast right now. Last signal was 5h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A2004D, octal 50400115, decimal 10,616,909.
What flights does A2004D operate?
Mode-S A2004D has broadcast 1 distinct callsign, including N228SD.