Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

AE503D

ICAO 24-bit transponder address

Currently assigned to 09-0540 · Boeing C-40C Clipper

Hex
AE503D
Octal
53450075
Decimal
11,423,805
Tail
09-0540
Type
B737
No current signal · last broadcast 1d ago
Flights observed
4
Distinct callsigns
2
Country
-
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S AE503D.

Callsign history 2 distinct

Callsign Airline Flights Last seen
AVLON73 - 2 2026-04-17
AVLON43 - 2 2026-04-14

Recent flights last 4

DateFlightRouteTakeoffLandingDuration
2026-04-17 AVLON73 - Apr 17, 15:20 UTCApr 17, 16:35 UTC1h 15m
2026-04-17 AVLON73 - Apr 17, 14:00 UTCApr 17, 15:15 UTC1h 15m
2026-04-14 AVLON43 - Apr 14, 16:50 UTCApr 14, 17:45 UTC55m
2026-04-14 AVLON43 - Apr 14, 16:05 UTCApr 14, 16:45 UTC40m

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 09-0540 page for operator, model, and routing details .

Mode-S AE503D frequently asked

What is Mode-S code AE503D?
AE503D is an ICAO 24-bit transponder address. Assigned to 09-0540.
Is AE503D 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 AE503D, octal 53450075, decimal 11,423,805.
What flights does AE503D operate?
Mode-S AE503D has broadcast 2 distinct callsigns, including AVLON73, AVLON43.