sensors Mode-S transponder

491D88

ICAO 24-bit transponder address · allocated to Portugal

Currently assigned to CS-GLH · BOMBARDIER BD-700 Global 6000/6500

Hex
491D88
Octal
22216610
Decimal
4,791,688
Country
PT
Tail
CS-GLH
Type
GLEX
No current signal · last broadcast 1h ago
Flights observed
5
Distinct callsigns
5
Country
PT
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S 491D88.

Country allocation

The ICAO 24-bit address 491D88 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 5 distinct

Callsign Airline Flights Last seen
NJE9MD - 1 2026-06-18
NJE913A - 1 2026-06-11
NJE844U - 1 2026-06-19
NJE368Y - 1 2026-06-11
NJE351F - 1 2026-06-12

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-06-19 NJE844U - Jun 19, 13:34 UTCJun 19, 13:59 UTC25m
2026-06-18 NJE9MD - Jun 18, 15:45 UTCJun 18, 17:45 UTC2h 0m
2026-06-12 NJE351F BQH → TEB Jun 12, 09:45 UTCJun 12, 17:05 UTC7h 20m
2026-06-11 NJE913A - Jun 11, 11:40 UTCJun 11, 13:05 UTC1h 25m
2026-06-11 NJE368Y - Jun 11, 09:20 UTCJun 11, 10:35 UTC1h 15m

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

Mode-S 491D88 frequently asked

What is Mode-S code 491D88?
491D88 is an ICAO 24-bit transponder address. Allocated to Portugal. Assigned to CS-GLH.
Where is Mode-S 491D88 registered?
Mode-S code 491D88 is allocated to Portugal (PT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 491D88 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 491D88, octal 22216610, decimal 4,791,688.
What flights does 491D88 operate?
Mode-S 491D88 has broadcast 5 distinct callsigns, including NJE9MD, NJE913A, NJE844U, NJE368Y, NJE351F.