Apparatus

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sensors Mode-S transponder

A4B57E

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N402QS · EMBRAER EMB-505 Phenom 300 · operated by NETJETS SALES INC, DEXTER AVIATION LLC, HAPPY BEANER LLC

Hex
A4B57E
Octal
51132576
Decimal
10,794,366
Country
US
Tail
N402QS
Type
E55P
Broadcasting now · callsign EJA402 · 10,900 ft
Flights observed
4
Distinct callsigns
1
Country
US
Last broadcast
2d ago

Current position

A4B57E is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A4B57E 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
EJA402 NetJets 4 2026-04-13

Recent flights last 4

DateFlightRouteTakeoffLandingDuration
2026-04-13 EJA402 SBA → SJC Apr 13, 03:55 UTCApr 13, 04:15 UTC20m
2026-04-13 EJA402 SBA → SJC Apr 13, 03:25 UTCApr 13, 04:15 UTC50m
2026-04-13 EJA402 SBA → SJC Apr 13, 01:15 UTCApr 13, 02:20 UTC1h 5m
2026-04-12 EJA402 SBA → SJC Apr 12, 23:55 UTCApr 13, 00:15 UTC20m

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 N402QS page for operator, model, and routing details .

Mode-S A4B57E frequently asked

What is Mode-S code A4B57E?
A4B57E is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N402QS.
Where is Mode-S A4B57E registered?
Mode-S code A4B57E 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 A4B57E broadcasting right now?
Yes. Mode-S A4B57E is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A4B57E, octal 51132576, decimal 10,794,366.
What flights does A4B57E operate?
Mode-S A4B57E has broadcast 1 distinct callsign, including EJA402.