sensors Mode-S transponder

AD4521

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N954SP · BOMBARDIER BD-700 Global 6000/6500 · operated by TVPX AIRCRAFT SOLUTIONS INC TRUSTEE

Hex
AD4521
Octal
53242441
Decimal
11,355,425
Country
US
Tail
N954SP
Type
GLEX
No current signal · last broadcast 2d ago
Flights observed
40
Distinct callsigns
1
Country
US
Last broadcast
2d ago

Last known position

Most recent position reported by Mode-S AD4521.

Country allocation

The ICAO 24-bit address AD4521 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
N954SP - 40 2026-06-03

Recent flights last 40

DateFlightRouteTakeoffLandingDuration
2026-06-03 N954SP - Jun 3, 19:05 UTCJun 4, 00:25 UTC5h 20m
2026-06-03 N954SP - Jun 3, 14:10 UTCJun 3, 16:25 UTC2h 15m
2026-06-01 N954SP - Jun 1, 21:00 UTCJun 1, 21:30 UTC30m
2026-06-01 N954SP - Jun 1, 15:00 UTCJun 1, 18:20 UTC3h 20m
2026-06-01 N954SP - Jun 1, 00:55 UTCJun 1, 01:10 UTC15m
2026-05-29 N954SP - May 29, 23:30 UTCMay 30, 00:05 UTC35m
2026-05-23 N954SP - May 23, 17:10 UTCMay 23, 17:45 UTC35m
2026-05-21 N954SP TEB → VNY May 21, 05:05 UTCMay 21, 10:45 UTC5h 40m
2026-05-20 N954SP OAK → TEB May 20, 12:10 UTCMay 20, 16:40 UTC4h 30m
2026-05-19 N954SP VNY → OAK May 19, 21:35 UTCMay 19, 22:30 UTC55m
2026-05-15 N954SP - May 15, 14:35 UTCMay 15, 18:15 UTC3h 39m
2026-05-13 N954SP VNY → BNA May 13, 16:30 UTCMay 13, 19:55 UTC3h 25m
2026-05-06 N954SP - May 6, 16:00 UTCMay 6, 21:05 UTC5h 4m
2026-05-05 N954SP - May 5, 19:05 UTCMay 5, 20:45 UTC1h 40m
2026-05-05 N954SP - May 5, 15:35 UTCMay 5, 18:35 UTC3h 0m
2026-05-05 N954SP - May 5, 14:05 UTCMay 5, 14:40 UTC35m
2026-05-03 N954SP - May 3, 15:30 UTCMay 3, 18:30 UTC3h 0m
2026-05-03 N954SP - May 3, 13:30 UTCMay 3, 14:55 UTC1h 25m
2026-04-30 N954SP - Apr 30, 19:35 UTCApr 30, 20:55 UTC1h 20m
2026-04-30 N954SP - Apr 30, 16:35 UTCApr 30, 19:00 UTC2h 25m
2026-04-28 N954SP - Apr 28, 02:10 UTCApr 28, 02:30 UTC20m
2026-04-28 N954SP - Apr 28, 00:30 UTCApr 28, 01:15 UTC45m
2026-04-27 N954SP - Apr 27, 04:30 UTCApr 27, 07:00 UTC2h 30m
2026-04-27 N954SP - Apr 27, 00:40 UTCApr 27, 03:55 UTC3h 15m
2026-04-24 N954SP - Apr 24, 16:10 UTCApr 24, 18:40 UTC2h 30m
2026-04-24 N954SP - Apr 24, 14:50 UTCApr 24, 15:40 UTC50m
2026-04-23 N954SP - Apr 23, 22:25 UTCApr 24, 00:35 UTC2h 10m
2026-04-18 N954SP - Apr 18, 01:25 UTCApr 18, 01:50 UTC25m
2026-04-17 N954SP - Apr 17, 23:25 UTCApr 18, 01:20 UTC1h 55m
2026-04-17 N954SP - Apr 17, 21:25 UTCApr 17, 23:20 UTC1h 55m
2026-04-17 N954SP - Apr 17, 20:30 UTCApr 17, 21:20 UTC50m
2026-04-17 N954SP BNA → TEB Apr 17, 03:45 UTCApr 17, 05:15 UTC1h 31m
2026-04-17 N954SP - Apr 17, 01:20 UTCApr 17, 02:59 UTC1h 40m
2026-04-16 N954SP - Apr 16, 23:35 UTCApr 17, 01:15 UTC1h 40m
2026-04-16 N954SP HSH → VNY Apr 16, 04:00 UTCApr 16, 04:44 UTC45m
2026-04-15 N954SP VNY → HSH Apr 15, 19:40 UTCApr 15, 20:20 UTC40m
2026-04-14 N954SP - Apr 14, 20:55 UTCApr 14, 22:15 UTC1h 20m
2026-04-14 N954SP - Apr 14, 19:35 UTCApr 14, 20:50 UTC1h 15m
2026-04-13 N954SP - Apr 13, 16:15 UTCApr 13, 18:10 UTC1h 55m
2026-04-13 N954SP - Apr 13, 15:55 UTCApr 13, 16:15 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 N954SP page for operator, model, and routing details .

Mode-S AD4521 frequently asked

What is Mode-S code AD4521?
AD4521 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N954SP.
Where is Mode-S AD4521 registered?
Mode-S code AD4521 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 AD4521 broadcasting right now?
No active broadcast right now. Last signal was 2d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AD4521, octal 53242441, decimal 11,355,425.
What flights does AD4521 operate?
Mode-S AD4521 has broadcast 1 distinct callsign, including N954SP.