sensors Mode-S transponder

4951CE

ICAO 24-bit transponder address · allocated to Portugal

Currently assigned to CS-TNN · AIRBUS A-320

Hex
4951CE
Octal
22250716
Decimal
4,805,070
Country
PT
Tail
CS-TNN
Type
A320
Photo of CS-TNN
No current signal · last broadcast 18h ago
Flights observed
11
Distinct callsigns
8
Country
PT
Last broadcast
18h ago

Last known position

Most recent position reported by Mode-S 4951CE.

Country allocation

The ICAO 24-bit address 4951CE 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 8 distinct

Callsign Airline Flights Last seen
TAP1736 - 3 2026-04-13
TAP646 - 2 2026-04-13
TAP647 TAP Portugal 1 2026-04-14
TAP1939 - 1 2026-04-13
TAP1735 - 1 2026-04-13
TAP1330 - 1 2026-04-12
TAP10AD - 1 2026-04-13
TAP1017 - 1 2026-04-13

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-14 TAP647 BRU → LIS Apr 14, 05:15 UTCApr 14, 06:30 UTC1h 15m
2026-04-13 TAP646 - Apr 13, 19:50 UTCApr 13, 21:50 UTC2h 0m
2026-04-13 TAP646 - Apr 13, 19:20 UTCApr 13, 20:10 UTC50m
2026-04-13 TAP1017 - Apr 13, 16:35 UTCApr 13, 17:35 UTC1h 0m
2026-04-13 TAP10AD - Apr 13, 14:20 UTCApr 13, 15:10 UTC50m
2026-04-13 TAP1736 - Apr 13, 12:20 UTCApr 13, 12:40 UTC20m
2026-04-13 TAP1736 - Apr 13, 12:00 UTCApr 13, 12:40 UTC40m
2026-04-13 TAP1736 - Apr 13, 11:10 UTCApr 13, 12:15 UTC1h 5m
2026-04-13 TAP1735 CAT → PXO Apr 13, 08:40 UTCApr 13, 10:00 UTC1h 20m
2026-04-13 TAP1939 - Apr 13, 06:15 UTCApr 13, 07:05 UTC50m
2026-04-12 TAP1330 OPO → LGW Apr 12, 17:45 UTCApr 12, 19:35 UTC1h 50m

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-TNN page for operator, model, and routing details .

Mode-S 4951CE frequently asked

What is Mode-S code 4951CE?
4951CE is an ICAO 24-bit transponder address. Allocated to Portugal. Assigned to CS-TNN.
Where is Mode-S 4951CE registered?
Mode-S code 4951CE is allocated to Portugal (PT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4951CE broadcasting right now?
No active broadcast right now. Last signal was 18h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4951CE, octal 22250716, decimal 4,805,070.
What flights does 4951CE operate?
Mode-S 4951CE has broadcast 8 distinct callsigns, including TAP1736, TAP646, TAP647, TAP1939, TAP1735.