sensors Mode-S transponder

AC4A7A

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N891QS · operated by TEXTRON AVIATION INC

Hex
AC4A7A
Octal
53045172
Decimal
11,291,258
Country
US
Tail
N891QS
Type
C700
Broadcasting now · callsign EJA891 · 39,000 ft
Flights observed
6
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Current position

AC4A7A is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address AC4A7A 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
EJA891 - 6 2026-04-13

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-13 EJA891 - Apr 13, 16:15 UTCApr 13, 16:40 UTC25m
2026-04-13 EJA891 - Apr 13, 15:50 UTCApr 13, 16:40 UTC50m
2026-04-13 EJA891 - Apr 13, 12:20 UTCApr 13, 16:15 UTC3h 55m
2026-04-13 EJA891 - Apr 13, 11:45 UTCApr 13, 12:15 UTC30m
2026-04-12 EJA891 - Apr 12, 19:10 UTCApr 12, 20:15 UTC1h 5m
2026-04-12 EJA891 - Apr 12, 17:15 UTCApr 12, 17:45 UTC30m

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 N891QS page for operator, model, and routing details .

Mode-S AC4A7A frequently asked

What is Mode-S code AC4A7A?
AC4A7A is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N891QS.
Where is Mode-S AC4A7A registered?
Mode-S code AC4A7A 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 AC4A7A broadcasting right now?
Yes. Mode-S AC4A7A is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC4A7A, octal 53045172, decimal 11,291,258.
What flights does AC4A7A operate?
Mode-S AC4A7A has broadcast 1 distinct callsign, including EJA891.