Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

AED557

ICAO 24-bit transponder address

Hex
AED557
Octal
53552527
Decimal
11,457,879
No current signal · last broadcast 10d ago
Flights observed
4
Distinct callsigns
2
Country
-
Last broadcast
10d ago

Last known position

Most recent position reported by Mode-S AED557.

Callsign history 2 distinct

Callsign Airline Flights Last seen
GUMP35 - 2 2026-05-19
GUMP34 - 2 2026-05-20

Recent flights last 4

DateFlightRouteTakeoffLandingDuration
2026-05-20 GUMP34 - May 20, 02:15 UTCMay 20, 02:30 UTC15m
2026-05-19 GUMP34 - May 19, 23:25 UTCMay 19, 23:40 UTC15m
2026-05-19 GUMP35 - May 19, 03:50 UTCMay 19, 04:00 UTC10m
2026-05-19 GUMP35 - May 19, 01:45 UTCMay 19, 03:00 UTC1h 15m

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.

Mode-S AED557 frequently asked

What is Mode-S code AED557?
AED557 is an ICAO 24-bit transponder address.
Is AED557 broadcasting right now?
No active broadcast right now. Last signal was 10d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AED557, octal 53552527, decimal 11,457,879.
What flights does AED557 operate?
Mode-S AED557 has broadcast 2 distinct callsigns, including GUMP35, GUMP34.