sensors Mode-S transponder

ACF888

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N935DA · DIAMOND DA-20 · operated by CAE DOSS AVIATION INC

Hex
ACF888
Octal
53174210
Decimal
11,335,816
Country
US
Tail
N935DA
Type
DV20
No current signal · last broadcast 4d ago
Flights observed
1
Distinct callsigns
1
Country
US
Last broadcast
4d ago

Last known position

Most recent position reported by Mode-S ACF888.

Country allocation

The ICAO 24-bit address ACF888 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
TG21 Thai Airways International 1 2026-04-14

Recent flights last 1

DateFlightRouteTakeoffLandingDuration
2026-04-14 TG21 UBP → BKK Apr 14, 15:40 UTCApr 14, 16:35 UTC55m

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 N935DA page for operator, model, and routing details .

Mode-S ACF888 frequently asked

What is Mode-S code ACF888?
ACF888 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N935DA.
Where is Mode-S ACF888 registered?
Mode-S code ACF888 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 ACF888 broadcasting right now?
No active broadcast right now. Last signal was 4d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex ACF888, octal 53174210, decimal 11,335,816.
What flights does ACF888 operate?
Mode-S ACF888 has broadcast 1 distinct callsign, including TG21.