sensors Mode-S transponder

A9E957

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N738FY · CESSNA 172 Skyhawk · operated by VERO TECHNICAL SUPPORT INC

Hex
A9E957
Octal
52364527
Decimal
11,135,319
Country
US
Tail
N738FY
Type
C172
No current signal · last broadcast 1d ago
Flights observed
7
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A9E957.

Country allocation

The ICAO 24-bit address A9E957 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
BL8FY - 7 2026-04-13

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-13 BL8FY - Apr 13, 21:25 UTCApr 13, 22:25 UTC1h 0m
2026-04-13 BL8FY - Apr 13, 19:50 UTCApr 13, 20:30 UTC40m
2026-04-13 BL8FY - Apr 13, 19:15 UTCApr 13, 20:10 UTC55m
2026-04-13 BL8FY - Apr 13, 16:15 UTCApr 13, 16:25 UTC10m
2026-04-13 BL8FY - Apr 13, 15:50 UTCApr 13, 16:25 UTC35m
2026-04-13 BL8FY - Apr 13, 15:40 UTCApr 13, 16:15 UTC35m
2026-04-13 BL8FY - Apr 13, 12:45 UTCApr 13, 13:55 UTC1h 10m

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 N738FY page for operator, model, and routing details .

Mode-S A9E957 frequently asked

What is Mode-S code A9E957?
A9E957 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N738FY.
Where is Mode-S A9E957 registered?
Mode-S code A9E957 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 A9E957 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 A9E957, octal 52364527, decimal 11,135,319.
What flights does A9E957 operate?
Mode-S A9E957 has broadcast 1 distinct callsign, including BL8FY.