sensors Mode-S transponder

491D9A

ICAO 24-bit transponder address · allocated to Portugal

Currently assigned to CS-GLZ · BOMBARDIER BD-700 Global 5000/5500

Hex
491D9A
Octal
22216632
Decimal
4,791,706
Country
PT
Tail
CS-GLZ
Type
GL5T
No current signal
Flights observed
0
Distinct callsigns
20
Country
PT
Last broadcast
-

Country allocation

The ICAO 24-bit address 491D9A 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 20 distinct

Callsign Airline Flights Last seen
NJE3HA - 10 2026-07-17
NJE838H - 3 2026-07-02
NJE633A - 2 2026-06-28
NJE521W - 2 2026-07-12
NJE302Y - 2 2026-04-25
NJE128N - 2 2026-04-16
NJE117E - 2 2026-04-16
NJE049V - 2 2026-04-17
NJU969D - 1 2026-06-22
NJU478L - 1 2026-06-01
NJU131C - 1 2026-07-02
NJU018E - 1 2026-05-22
NJE996B - 1 2026-06-11
NJE978F - 1 2026-06-11
NJE977E - 1 2026-07-03
NJE968L - 1 2026-07-15
NJE952R - 1 2026-04-13
NJE894C - 1 2026-06-12
NJE884H - 1 2026-06-05
NJE881H - 1 2026-05-25

Recent flights

No flights recorded yet for this transponder.

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

Mode-S 491D9A frequently asked

What is Mode-S code 491D9A?
491D9A is an ICAO 24-bit transponder address. Allocated to Portugal. Assigned to CS-GLZ.
Where is Mode-S 491D9A registered?
Mode-S code 491D9A is allocated to Portugal (PT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 491D9A broadcasting right now?
No active broadcast right now.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 491D9A, octal 22216632, decimal 4,791,706.
What flights does 491D9A operate?
Mode-S 491D9A has broadcast 20 distinct callsigns, including NJE3HA, NJE838H, NJE633A, NJE521W, NJE302Y.