sensors Mode-S transponder

A19551

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N2007A · AIR TRACTOR AT-602 · operated by 2007A LLC

Hex
A19551
Octal
50312521
Decimal
10,589,521
Country
US
Tail
N2007A
Type
AT6T
No current signal · last broadcast Jul 26, 01:45 UTC
Flights observed
6
Distinct callsigns
1
Country
US
Last broadcast
Jul 26, 01:45 UTC

Last known position

Most recent position reported by Mode-S A19551.

Country allocation

The ICAO 24-bit address A19551 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
N2007A - 5 2026-07-26

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-07-26 N2007A - Jul 26, 01:30 UTCJul 26, 01:45 UTC15m
2026-07-25 N2007A - Jul 25, 22:35 UTCJul 25, 23:50 UTC1h 15m
2026-07-20 N2007A - Jul 20, 16:15 UTCJul 20, 16:45 UTC30m
2026-07-13 - - Jul 13, 13:40 UTCJul 13, 13:50 UTC10m
2026-07-04 N2007A - Jul 4, 13:20 UTCJul 4, 13:30 UTC10m
2026-06-24 N2007A - Jun 24, 15:24 UTCJun 24, 15:49 UTC25m

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 N2007A page for operator, model, and routing details .

Mode-S A19551 frequently asked

What is Mode-S code A19551?
A19551 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N2007A.
Where is Mode-S A19551 registered?
Mode-S code A19551 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 A19551 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 01:45 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A19551, octal 50312521, decimal 10,589,521.
What flights does A19551 operate?
Mode-S A19551 has broadcast 1 distinct callsign, including N2007A.