sensors Mode-S transponder

A13668

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N1776R · operated by ROMEO VELA

Hex
A13668
Octal
50233150
Decimal
10,565,224
Country
US
Tail
N1776R
No current signal · last broadcast 1h ago
Flights observed
5
Distinct callsigns
2
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S A13668.

Country allocation

The ICAO 24-bit address A13668 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
SWA8725 Southwest Airlines 4 2026-04-27
SWA1253 Southwest Airlines 1 2026-04-29

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-29 SWA1253 SAN → OAK Apr 29, 14:15 UTCApr 29, 16:00 UTC1h 45m
2026-04-27 SWA8725 BDL → BWI Apr 27, 23:55 UTCApr 28, 02:45 UTC2h 50m
2026-04-27 SWA8725 BDL → BWI Apr 27, 23:54 UTCApr 28, 02:37 UTC2h 43m
2026-04-25 SWA8725 BDL → BWI Apr 25, 04:25 UTCApr 25, 08:25 UTC4h 0m
2026-04-25 SWA8725 BDL → BWI Apr 25, 04:22 UTCApr 25, 08:20 UTC3h 58m

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 N1776R page for operator, model, and routing details .

Mode-S A13668 frequently asked

What is Mode-S code A13668?
A13668 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N1776R.
Where is Mode-S A13668 registered?
Mode-S code A13668 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 A13668 broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A13668, octal 50233150, decimal 10,565,224.
What flights does A13668 operate?
Mode-S A13668 has broadcast 2 distinct callsigns, including SWA8725, SWA1253.