Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

AE77C4

ICAO 24-bit transponder address

Currently assigned to 22-21248 · SIKORSKY UH-60 Black Hawk

Hex
AE77C4
Octal
53473704
Decimal
11,433,924
Tail
22-21248
Type
H60
No current signal · last broadcast 1d ago
Flights observed
4
Distinct callsigns
1
Country
-
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S AE77C4.

Callsign history 1 distinct

Callsign Airline Flights Last seen
PAT22 - 4 2026-04-13

Recent flights last 4

DateFlightRouteTakeoffLandingDuration
2026-04-13 PAT22 - Apr 13, 19:55 UTCApr 13, 20:35 UTC40m
2026-04-13 PAT22 - Apr 13, 12:20 UTCApr 13, 12:40 UTC20m
2026-04-13 PAT22 - Apr 13, 12:10 UTCApr 13, 12:40 UTC30m
2026-04-13 PAT22 - Apr 13, 11:10 UTCApr 13, 12:15 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 22-21248 page for operator, model, and routing details .

Mode-S AE77C4 frequently asked

What is Mode-S code AE77C4?
AE77C4 is an ICAO 24-bit transponder address. Assigned to 22-21248.
Is AE77C4 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 AE77C4, octal 53473704, decimal 11,433,924.
What flights does AE77C4 operate?
Mode-S AE77C4 has broadcast 1 distinct callsign, including PAT22.