sensors Mode-S transponder

AC9B66

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N911LK · SIKORSKY S-76 Spirit · operated by AGUSTAWESTLAND PHILADELPHIA CORP

Hex
AC9B66
Octal
53115546
Decimal
11,311,974
Country
US
Tail
N911LK
Type
S76
No current signal · last broadcast 22h ago
Flights observed
35
Distinct callsigns
1
Country
US
Last broadcast
22h ago

Last known position

Most recent position reported by Mode-S AC9B66.

Country allocation

The ICAO 24-bit address AC9B66 falls within the block assigned to United States (US) by ICAO Annex 10, Volume III. Every aircraft registered in United States 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 1 distinct

Callsign Airline Flights Last seen
N911LK - 35 2026-06-12

Recent flights last 35

DateFlightRouteTakeoffLandingDuration
2026-06-12 N911LK - Jun 12, 04:05 UTCJun 12, 05:15 UTC1h 10m
2026-06-10 N911LK - Jun 10, 19:15 UTCJun 10, 20:05 UTC50m
2026-06-10 N911LK - Jun 10, 14:50 UTCJun 10, 15:25 UTC35m
2026-06-10 N911LK - Jun 10, 05:45 UTCJun 10, 06:55 UTC1h 10m
2026-06-09 N911LK - Jun 9, 03:20 UTCJun 9, 03:45 UTC25m
2026-06-09 N911LK - Jun 9, 02:50 UTCJun 9, 03:00 UTC10m
2026-06-04 N911LK - Jun 4, 08:30 UTCJun 4, 09:10 UTC40m
2026-06-02 N911LK - Jun 2, 05:45 UTCJun 2, 06:25 UTC40m
2026-05-29 N911LK - May 29, 23:35 UTCMay 30, 00:15 UTC40m
2026-05-23 N911LK - May 23, 04:35 UTCMay 23, 05:45 UTC1h 10m
2026-05-23 N911LK - May 23, 02:30 UTCMay 23, 02:55 UTC25m
2026-05-23 N911LK - May 23, 01:55 UTCMay 23, 02:25 UTC30m
2026-05-22 N911LK - May 22, 22:15 UTCMay 22, 23:10 UTC55m
2026-05-21 N911LK - May 21, 00:20 UTCMay 21, 01:00 UTC40m
2026-05-19 N911LK - May 19, 20:55 UTCMay 19, 21:30 UTC35m
2026-05-18 N911LK - May 18, 16:45 UTCMay 18, 17:30 UTC45m
2026-05-14 N911LK - May 14, 13:01 UTCMay 14, 14:15 UTC1h 15m
2026-05-13 N911LK - May 13, 15:20 UTCMay 13, 16:40 UTC1h 20m
2026-05-11 N911LK - May 11, 15:15 UTCMay 11, 15:25 UTC10m
2026-05-11 N911LK - May 11, 14:45 UTCMay 11, 15:00 UTC15m
2026-05-11 N911LK - May 11, 04:20 UTCMay 11, 04:40 UTC20m
2026-05-11 N911LK - May 11, 03:55 UTCMay 11, 04:10 UTC15m
2026-05-10 N911LK - May 10, 22:45 UTCMay 10, 23:05 UTC20m
2026-05-10 N911LK - May 10, 22:25 UTCMay 10, 22:40 UTC15m
2026-05-07 N911LK - May 7, 21:15 UTCMay 7, 22:00 UTC45m
2026-05-05 N911LK - May 5, 19:20 UTCMay 5, 19:30 UTC10m
2026-05-05 N911LK - May 5, 18:50 UTCMay 5, 19:00 UTC10m
2026-05-03 N911LK - May 3, 21:54 UTCMay 3, 22:34 UTC40m
2026-05-03 N911LK - May 3, 01:55 UTCMay 3, 02:10 UTC15m
2026-05-03 N911LK - May 3, 01:30 UTCMay 3, 01:45 UTC15m
2026-05-02 N911LK - May 2, 02:30 UTCMay 2, 02:45 UTC15m
2026-05-02 N911LK - May 2, 00:30 UTCMay 2, 01:55 UTC1h 25m
2026-05-01 N911LK - May 1, 19:50 UTCMay 1, 20:15 UTC25m
2026-04-30 N911LK - Apr 30, 14:00 UTCApr 30, 14:35 UTC35m
2026-04-13 N911LK - Apr 13, 14:30 UTCApr 13, 15:15 UTC45m

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 N911LK page for operator, model, and routing details .

Mode-S AC9B66 frequently asked

What is Mode-S code AC9B66?
AC9B66 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N911LK.
Where is Mode-S AC9B66 registered?
Mode-S code AC9B66 is allocated to United States (US). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is AC9B66 broadcasting right now?
No active broadcast right now. Last signal was 22h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC9B66, octal 53115546, decimal 11,311,974.
What flights does AC9B66 operate?
Mode-S AC9B66 has broadcast 1 distinct callsign, including N911LK.