sensors Mode-S transponder

A953CD

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N70SH · VANS RV-7 · operated by GARMIN INTERNATIONAL

Hex
A953CD
Octal
52251715
Decimal
11,097,037
Country
US
Tail
N70SH
Type
RV7
No current signal · last broadcast 1d ago
Flights observed
7
Distinct callsigns
2
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A953CD.

Country allocation

The ICAO 24-bit address A953CD 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 2 distinct

Callsign Airline Flights Last seen
GRM20 - 5 2026-05-28
GARMN20 - 2 2026-05-27

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-05-28 GRM20 - May 28, 22:45 UTCMay 28, 23:15 UTC30m
2026-05-28 GRM20 - May 28, 20:45 UTCMay 28, 22:05 UTC1h 20m
2026-05-28 GRM20 - May 28, 19:15 UTCMay 28, 20:05 UTC50m
2026-05-28 GRM20 - May 28, 15:40 UTCMay 28, 18:05 UTC2h 25m
2026-05-28 GRM20 - May 28, 14:35 UTCMay 28, 15:10 UTC35m
2026-05-27 GARMN20 - May 27, 14:45 UTCMay 27, 15:25 UTC40m
2026-05-20 GARMN20 - May 20, 19:15 UTCMay 20, 19:35 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 N70SH page for operator, model, and routing details .

Mode-S A953CD frequently asked

What is Mode-S code A953CD?
A953CD is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N70SH.
Where is Mode-S A953CD registered?
Mode-S code A953CD 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 A953CD 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 A953CD, octal 52251715, decimal 11,097,037.
What flights does A953CD operate?
Mode-S A953CD has broadcast 2 distinct callsigns, including GRM20, GARMN20.