sensors Mode-S transponder

0D121B

ICAO 24-bit transponder address · allocated to Mexico

Currently assigned to XA-OTC · BOEING 737 MAX 8

Hex
0D121B
Octal
03211033
Decimal
856,603
Country
MX
Tail
XA-OTC
Type
B38M
No current signal · last broadcast 1d ago
Flights observed
14
Distinct callsigns
7
Country
MX
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 0D121B.

Country allocation

The ICAO 24-bit address 0D121B falls within the block assigned to Mexico (MX) by ICAO Annex 10, Volume III. Every aircraft registered in Mexico 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 7 distinct

Callsign Airline Flights Last seen
AMX195 - 4 2026-04-13
AMX835 - 2 2026-04-13
AMX705 - 2 2026-04-13
AMX702 - 2 2026-04-13
AMX186 - 2 2026-04-13
AMX609 - 1 2026-04-12
AMX104 - 1 2026-04-13

Recent flights last 14

DateFlightRouteTakeoffLandingDuration
2026-04-13 AMX104 - Apr 13, 20:30 UTCApr 13, 23:15 UTC2h 45m
2026-04-13 AMX705 - Apr 13, 18:40 UTCApr 13, 18:50 UTC10m
2026-04-13 AMX705 - Apr 13, 16:45 UTCApr 13, 17:00 UTC15m
2026-04-13 AMX702 - Apr 13, 15:15 UTCApr 13, 15:30 UTC15m
2026-04-13 AMX702 - Apr 13, 13:10 UTCApr 13, 13:25 UTC15m
2026-04-13 AMX195 - Apr 13, 10:15 UTCApr 13, 10:20 UTC5m
2026-04-13 AMX195 - Apr 13, 08:20 UTCApr 13, 08:35 UTC15m
2026-04-13 AMX195 - Apr 13, 07:55 UTCApr 13, 08:35 UTC40m
2026-04-13 AMX195 - Apr 13, 07:30 UTCApr 13, 08:15 UTC45m
2026-04-13 AMX186 - Apr 13, 04:50 UTCApr 13, 06:10 UTC1h 20m
2026-04-13 AMX186 - Apr 13, 02:55 UTCApr 13, 03:10 UTC15m
2026-04-13 AMX835 - Apr 13, 00:20 UTCApr 13, 01:00 UTC40m
2026-04-12 AMX835 - Apr 12, 23:55 UTCApr 13, 01:00 UTC1h 5m
2026-04-12 AMX609 - Apr 12, 17:35 UTCApr 12, 18:15 UTC40m

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 XA-OTC page for operator, model, and routing details .

Mode-S 0D121B frequently asked

What is Mode-S code 0D121B?
0D121B is an ICAO 24-bit transponder address. Allocated to Mexico. Assigned to XA-OTC.
Where is Mode-S 0D121B registered?
Mode-S code 0D121B is allocated to Mexico (MX). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 0D121B 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 0D121B, octal 03211033, decimal 856,603.
What flights does 0D121B operate?
Mode-S 0D121B has broadcast 7 distinct callsigns, including AMX195, AMX835, AMX705, AMX702, AMX186.