sensors Mode-S transponder

ADD373

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N990JH · CESSNA 560 Citation Ultra · operated by BLUEBIRD OPPORTUNITIES LLC

Hex
ADD373
Octal
53351563
Decimal
11,391,859
Country
US
Tail
N990JH
Type
C560
Broadcasting now · callsign FFL1169 · 39,000 ft
Flights observed
12
Distinct callsigns
2
Country
US
Last broadcast
3h ago

Current position

ADD373 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address ADD373 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 2 distinct

Callsign Airline Flights Last seen
FFL1169 - 10 2026-05-26
FFL1380 - 2 2026-04-23

Recent flights last 12

DateFlightRouteTakeoffLandingDuration
2026-05-26 FFL1169 - May 26, 12:45 UTCMay 26, 14:05 UTC1h 20m
2026-05-20 FFL1169 - May 20, 02:45 UTCMay 20, 04:35 UTC1h 50m
2026-05-19 FFL1169 - May 19, 22:00 UTCMay 19, 23:45 UTC1h 45m
2026-05-19 FFL1169 - May 19, 01:45 UTCMay 19, 02:55 UTC1h 10m
2026-05-18 FFL1169 - May 18, 17:40 UTCMay 18, 19:05 UTC1h 24m
2026-05-17 FFL1169 - May 17, 21:05 UTCMay 18, 00:55 UTC3h 50m
2026-05-17 FFL1169 - May 17, 05:30 UTCMay 17, 08:20 UTC2h 50m
2026-05-16 FFL1169 - May 16, 21:25 UTCMay 16, 22:05 UTC40m
2026-05-14 FFL1169 - May 14, 20:45 UTCMay 14, 23:40 UTC2h 55m
2026-05-02 FFL1169 - May 2, 18:50 UTCMay 3, 06:00 UTC11h 9m
2026-04-23 FFL1380 - Apr 23, 16:55 UTCApr 23, 18:20 UTC1h 24m
2026-04-20 FFL1380 - Apr 20, 14:05 UTCApr 20, 15:25 UTC1h 20m

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 N990JH page for operator, model, and routing details .

Mode-S ADD373 frequently asked

What is Mode-S code ADD373?
ADD373 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N990JH.
Where is Mode-S ADD373 registered?
Mode-S code ADD373 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 ADD373 broadcasting right now?
Yes. Mode-S ADD373 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex ADD373, octal 53351563, decimal 11,391,859.
What flights does ADD373 operate?
Mode-S ADD373 has broadcast 2 distinct callsigns, including FFL1169, FFL1380.