sensors Mode-S transponder

AFA191

ICAO 24-bit transponder address

Currently assigned to 24-21303 · SIKORSKY UH-60 Black Hawk

Hex
AFA191
Octal
53720621
Decimal
11,510,161
Tail
24-21303
Type
H60
No current signal · last broadcast 3d ago
Flights observed
13
Distinct callsigns
2
Country
-
Last broadcast
3d ago

Last known position

Most recent position reported by Mode-S AFA191.

Callsign history 2 distinct

Callsign Airline Flights Last seen
21303 - 10 2026-06-22
G21303 - 3 2026-07-10

Recent flights last 13

DateFlightRouteTakeoffLandingDuration
2026-07-10 G21303 - Jul 10, 12:35 UTCJul 10, 12:50 UTC15m
2026-06-22 21303 - Jun 22, 18:19 UTCJun 22, 18:35 UTC15m
2026-06-22 21303 - Jun 22, 17:25 UTCJun 22, 17:40 UTC15m
2026-06-16 21303 - Jun 16, 15:55 UTCJun 16, 16:15 UTC20m
2026-06-16 21303 - Jun 16, 12:05 UTCJun 16, 12:50 UTC45m
2026-06-14 21303 - Jun 14, 18:00 UTCJun 14, 18:35 UTC35m
2026-06-10 21303 MGW → MGW Jun 10, 21:35 UTCJun 10, 21:40 UTC5m
2026-06-06 21303 - Jun 6, 21:25 UTCJun 6, 21:35 UTC10m
2026-06-02 21303 - Jun 2, 21:55 UTCJun 2, 22:15 UTC20m
2026-06-02 21303 - Jun 2, 18:40 UTCJun 2, 18:45 UTC5m
2026-06-01 21303 - Jun 1, 16:00 UTCJun 1, 16:20 UTC20m
2026-04-20 G21303 - Apr 20, 18:35 UTCApr 20, 18:45 UTC10m
2026-04-20 G21303 - Apr 20, 12:25 UTCApr 20, 12:40 UTC16m

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 24-21303 page for operator, model, and routing details .

Mode-S AFA191 frequently asked

What is Mode-S code AFA191?
AFA191 is an ICAO 24-bit transponder address. Assigned to 24-21303.
Is AFA191 broadcasting right now?
No active broadcast right now. Last signal was 3d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AFA191, octal 53720621, decimal 11,510,161.
What flights does AFA191 operate?
Mode-S AFA191 has broadcast 2 distinct callsigns, including 21303, G21303.