sensors Mode-S transponder

A9B971

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N7257E · CESSNA 172R Cutlass RG · operated by WILLIAMS MARK A

Hex
A9B971
Octal
52334561
Decimal
11,123,057
Country
US
Tail
N7257E
Type
C72R
No current signal · last broadcast 1d ago
Flights observed
5
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A9B971.

Country allocation

The ICAO 24-bit address A9B971 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
N7257E - 5 2026-04-13

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-13 N7257E - Apr 13, 21:30 UTCApr 13, 23:40 UTC2h 10m
2026-04-13 N7257E MYF → MYF Apr 13, 17:45 UTCApr 13, 18:30 UTC45m
2026-04-13 N7257E MYF → MYF Apr 13, 16:15 UTCApr 13, 16:55 UTC40m
2026-04-13 N7257E MYF → MYF Apr 13, 15:50 UTCApr 13, 16:55 UTC1h 5m
2026-04-13 N7257E MYF → MYF Apr 13, 15:30 UTCApr 13, 16:15 UTC45m

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 N7257E page for operator, model, and routing details .

Mode-S A9B971 frequently asked

What is Mode-S code A9B971?
A9B971 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N7257E.
Where is Mode-S A9B971 registered?
Mode-S code A9B971 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 A9B971 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 A9B971, octal 52334561, decimal 11,123,057.
What flights does A9B971 operate?
Mode-S A9B971 has broadcast 1 distinct callsign, including N7257E.