sensors Mode-S transponder

77044F

ICAO 24-bit transponder address · allocated to Sri Lanka

Currently assigned to 4R-ABO · AIRBUS A-320

Hex
77044F
Octal
35602117
Decimal
7,799,887
Country
LK
Tail
4R-ABO
Type
A320
No current signal · last broadcast 18h ago
Flights observed
6
Distinct callsigns
6
Country
LK
Last broadcast
18h ago

Last known position

Most recent position reported by Mode-S 77044F.

Country allocation

The ICAO 24-bit address 77044F falls within the block assigned to Sri Lanka (LK) by ICAO Annex 10, Volume III. Every aircraft registered in Sri Lanka 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 6 distinct

Callsign Airline Flights Last seen
ALK403 - 1 2026-04-13
ALK306 - 1 2026-04-13
ALK172 - 1 2026-04-13
ALK171 SriLankan Airlines 1 2026-04-13
ALK120 - 1 2026-04-14
ALK119 - 1 2026-04-14

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-14 ALK120 - Apr 14, 10:25 UTCApr 14, 10:35 UTC10m
2026-04-14 ALK119 - Apr 14, 07:10 UTCApr 14, 07:20 UTC10m
2026-04-13 ALK306 - Apr 13, 23:20 UTCApr 13, 23:40 UTC20m
2026-04-13 ALK172 - Apr 13, 16:20 UTCApr 13, 16:50 UTC30m
2026-04-13 ALK171 CMB → BLR Apr 13, 14:20 UTCApr 13, 14:55 UTC35m
2026-04-13 ALK403 - Apr 13, 00:45 UTCApr 13, 01:05 UTC20m

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 4R-ABO page for operator, model, and routing details .

Mode-S 77044F frequently asked

What is Mode-S code 77044F?
77044F is an ICAO 24-bit transponder address. Allocated to Sri Lanka. Assigned to 4R-ABO.
Where is Mode-S 77044F registered?
Mode-S code 77044F is allocated to Sri Lanka (LK). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 77044F 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 77044F, octal 35602117, decimal 7,799,887.
What flights does 77044F operate?
Mode-S 77044F has broadcast 6 distinct callsigns, including ALK403, ALK306, ALK172, ALK171, ALK120.