sensors Mode-S transponder

AE6221

ICAO 24-bit transponder address

Currently assigned to 18-21021 · SIKORSKY UH-60 Black Hawk

Hex
AE6221
Octal
53461041
Decimal
11,428,385
Tail
18-21021
Type
H60
No current signal · last broadcast 13h ago
Flights observed
7
Distinct callsigns
3
Country
-
Last broadcast
13h ago

Last known position

Most recent position reported by Mode-S AE6221.

Callsign history 3 distinct

Callsign Airline Flights Last seen
HOIST03 - 3 2026-04-13
HOIST30 - 2 2026-04-13
HOIST26 - 2 2026-04-14

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-14 HOIST26 - Apr 14, 09:50 UTCApr 14, 10:10 UTC20m
2026-04-14 HOIST26 - Apr 14, 08:45 UTCApr 14, 08:55 UTC10m
2026-04-13 HOIST03 - Apr 13, 13:05 UTCApr 13, 13:40 UTC35m
2026-04-13 HOIST03 - Apr 13, 12:05 UTCApr 13, 12:15 UTC10m
2026-04-13 HOIST03 - Apr 13, 10:15 UTCApr 13, 11:55 UTC1h 40m
2026-04-13 HOIST30 - Apr 13, 07:25 UTCApr 13, 07:45 UTC20m
2026-04-13 HOIST30 - Apr 13, 03:30 UTCApr 13, 03:55 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 18-21021 page for operator, model, and routing details .

Mode-S AE6221 frequently asked

What is Mode-S code AE6221?
AE6221 is an ICAO 24-bit transponder address. Assigned to 18-21021.
Is AE6221 broadcasting right now?
No active broadcast right now. Last signal was 13h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AE6221, octal 53461041, decimal 11,428,385.
What flights does AE6221 operate?
Mode-S AE6221 has broadcast 3 distinct callsigns, including HOIST03, HOIST30, HOIST26.