sensors Mode-S transponder

AA1E03

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N751CS · operated by UMB BANK NA TRUSTEE

Hex
AA1E03
Octal
52417003
Decimal
11,148,803
Country
US
Tail
N751CS
Type
B752
No current signal · last broadcast 1d ago
Flights observed
1
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S AA1E03.

Country allocation

The ICAO 24-bit address AA1E03 falls within the block assigned to United States (US) by ICAO Annex 10, Volume III. Every aircraft registered in United States receives a permanent address from this block at the time of registration; the address stays with the airframe even if the aircraft is re-registered to a different operator within the country.

Callsign history 1 distinct

Callsign Airline Flights Last seen
CSB507 21 Air 1 2026-04-13

Recent flights last 1

DateFlightRouteTakeoffLandingDuration
2026-04-13 CSB507 CVG → HRL Apr 13, 04:55 UTCApr 13, 07:35 UTC2h 40m

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 N751CS page for operator, model, and routing details .

Mode-S AA1E03 frequently asked

What is Mode-S code AA1E03?
AA1E03 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N751CS.
Where is Mode-S AA1E03 registered?
Mode-S code AA1E03 is allocated to United States (US). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is AA1E03 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 AA1E03, octal 52417003, decimal 11,148,803.
What flights does AA1E03 operate?
Mode-S AA1E03 has broadcast 1 distinct callsign, including CSB507.