sensors Mode-S transponder

4951D2

ICAO 24-bit transponder address · allocated to Portugal

Currently assigned to CS-TNR · AIRBUS A-320

Hex
4951D2
Octal
22250722
Decimal
4,805,074
Country
PT
Tail
CS-TNR
Type
A320
No current signal · last broadcast 12h ago
Flights observed
6
Distinct callsigns
4
Country
PT
Last broadcast
12h ago

Last known position

Most recent position reported by Mode-S 4951D2.

Country allocation

The ICAO 24-bit address 4951D2 falls within the block assigned to Portugal (PT) by ICAO Annex 10, Volume III. Every aircraft registered in Portugal 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 4 distinct

Callsign Airline Flights Last seen
TAP43RY - 2 2026-04-13
TAP438T TAP Portugal 2 2026-04-13
TAP30BC - 1 2026-04-14
TAP1031 - 1 2026-04-14

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-14 TAP1031 - Apr 14, 10:30 UTCApr 14, 11:05 UTC35m
2026-04-14 TAP30BC - Apr 14, 07:20 UTCApr 14, 08:50 UTC1h 30m
2026-04-13 TAP43RY - Apr 13, 19:50 UTCApr 13, 21:30 UTC1h 40m
2026-04-13 TAP43RY - Apr 13, 19:30 UTCApr 13, 20:10 UTC40m
2026-04-13 TAP438T LIS → ORY Apr 13, 16:15 UTCApr 13, 18:20 UTC2h 5m
2026-04-13 TAP438T LIS → ORY Apr 13, 16:10 UTCApr 13, 18:20 UTC2h 10m

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 CS-TNR page for operator, model, and routing details .

Mode-S 4951D2 frequently asked

What is Mode-S code 4951D2?
4951D2 is an ICAO 24-bit transponder address. Allocated to Portugal. Assigned to CS-TNR.
Where is Mode-S 4951D2 registered?
Mode-S code 4951D2 is allocated to Portugal (PT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4951D2 broadcasting right now?
No active broadcast right now. Last signal was 12h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4951D2, octal 22250722, decimal 4,805,074.
What flights does 4951D2 operate?
Mode-S 4951D2 has broadcast 4 distinct callsigns, including TAP43RY, TAP438T, TAP30BC, TAP1031.