sensors Mode-S transponder

AE51C4

ICAO 24-bit transponder address

Currently assigned to 11-20397 · SIKORSKY UH-60 Black Hawk

Hex
AE51C4
Octal
53450704
Decimal
11,424,196
Tail
11-20397
Type
H60
No current signal · last broadcast 12d ago
Flights observed
14
Distinct callsigns
4
Country
-
Last broadcast
12d ago

Last known position

Most recent position reported by Mode-S AE51C4.

Callsign history 4 distinct

Callsign Airline Flights Last seen
SPADE10 - 5 2026-07-01
SPADE33 - 4 2026-05-28
SPADE08 - 4 2026-06-23
HAZE37 - 1 2026-05-20

Recent flights last 14

DateFlightRouteTakeoffLandingDuration
2026-07-01 SPADE10 - Jul 1, 21:35 UTCJul 1, 22:45 UTC1h 10m
2026-07-01 SPADE10 WIE → WIE Jul 1, 21:05 UTCJul 1, 21:25 UTC20m
2026-07-01 SPADE10 WIE → WIE Jul 1, 20:25 UTCJul 1, 20:30 UTC5m
2026-06-30 SPADE10 WIE → WIE Jun 30, 21:20 UTCJun 30, 22:00 UTC40m
2026-06-30 SPADE10 WIE → WIE Jun 30, 20:40 UTCJun 30, 21:05 UTC25m
2026-06-23 SPADE08 WIE → WIE Jun 23, 21:05 UTCJun 23, 22:10 UTC1h 5m
2026-06-23 SPADE08 WIE → WIE Jun 23, 19:10 UTCJun 23, 20:10 UTC1h 0m
2026-06-03 SPADE08 - Jun 3, 20:45 UTCJun 3, 22:00 UTC1h 15m
2026-06-03 SPADE08 WIE → ILH Jun 3, 18:10 UTCJun 3, 20:00 UTC1h 50m
2026-05-28 SPADE33 - May 28, 21:50 UTCMay 28, 22:40 UTC50m
2026-05-28 SPADE33 WIE → WIE May 28, 21:30 UTCMay 28, 21:40 UTC10m
2026-05-28 SPADE33 WIE → WIE May 28, 21:15 UTCMay 28, 21:25 UTC10m
2026-05-28 SPADE33 WIE → WIE May 28, 20:55 UTCMay 28, 21:05 UTC10m
2026-05-20 HAZE37 ILH → WIE May 20, 07:10 UTCMay 20, 08:15 UTC1h 5m

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 11-20397 page for operator, model, and routing details .

Mode-S AE51C4 frequently asked

What is Mode-S code AE51C4?
AE51C4 is an ICAO 24-bit transponder address. Assigned to 11-20397.
Is AE51C4 broadcasting right now?
No active broadcast right now. Last signal was 12d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AE51C4, octal 53450704, decimal 11,424,196.
What flights does AE51C4 operate?
Mode-S AE51C4 has broadcast 4 distinct callsigns, including SPADE10, SPADE33, SPADE08, HAZE37.