sensors Mode-S transponder

A18978

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N1989B · DASSAULT Falcon 100 · operated by N455JW LLC

Hex
A18978
Octal
50304570
Decimal
10,586,488
Country
US
Tail
N1989B
Type
FA10
No current signal · last broadcast 16d ago
Flights observed
36
Distinct callsigns
1
Country
US
Last broadcast
16d ago

Last known position

Most recent position reported by Mode-S A18978.

Country allocation

The ICAO 24-bit address A18978 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
N1989B - 36 2026-07-05

Recent flights last 36

DateFlightRouteTakeoffLandingDuration
2026-07-05 N1989B - Jul 5, 21:30 UTCJul 5, 22:45 UTC1h 15m
2026-07-05 N1989B - Jul 5, 18:20 UTCJul 5, 18:45 UTC25m
2026-07-05 N1989B - Jul 5, 13:25 UTCJul 5, 17:40 UTC4h 15m
2026-07-04 N1989B - Jul 4, 17:20 UTCJul 4, 18:00 UTC40m
2026-07-01 N1989B - Jul 1, 18:40 UTCJul 1, 20:40 UTC2h 0m
2026-07-01 N1989B - Jul 1, 16:20 UTCJul 1, 18:00 UTC1h 40m
2026-07-01 N1989B - Jul 1, 15:15 UTCJul 1, 15:45 UTC30m
2026-06-26 N1989B LNS → FTW Jun 26, 18:09 UTCJun 26, 21:04 UTC2h 55m
2026-06-25 N1989B - Jun 25, 22:14 UTCJun 25, 22:59 UTC45m
2026-06-24 N1989B - Jun 24, 19:49 UTCJun 24, 21:44 UTC1h 55m
2026-06-13 N1989B - Jun 13, 14:30 UTCJun 13, 14:40 UTC10m
2026-06-12 N1989B - Jun 12, 00:05 UTCJun 12, 01:10 UTC1h 6m
2026-06-11 N1989B - Jun 11, 21:20 UTCJun 11, 23:20 UTC2h 0m
2026-06-11 N1989B - Jun 11, 20:15 UTCJun 11, 20:30 UTC15m
2026-06-08 N1989B ABE → TEB Jun 8, 19:05 UTCJun 8, 19:30 UTC25m
2026-06-08 N1989B - Jun 8, 17:20 UTCJun 8, 18:05 UTC45m
2026-06-08 N1989B - Jun 8, 11:35 UTCJun 8, 13:50 UTC2h 15m
2026-06-07 N1989B - Jun 7, 20:55 UTCJun 7, 21:25 UTC30m
2026-06-04 N1989B - Jun 4, 01:30 UTCJun 4, 02:15 UTC45m
2026-06-03 N1989B - Jun 3, 20:00 UTCJun 3, 20:25 UTC25m
2026-05-22 N1989B - May 22, 16:35 UTCMay 22, 16:45 UTC10m
2026-05-21 N1989B - May 21, 22:05 UTCMay 22, 00:35 UTC2h 30m
2026-05-17 N1989B - May 17, 17:30 UTCMay 17, 20:25 UTC2h 55m
2026-05-07 N1989B - May 7, 23:55 UTCMay 8, 02:14 UTC2h 20m
2026-05-07 N1989B - May 7, 18:50 UTCMay 7, 20:15 UTC1h 25m
2026-05-07 N1989B - May 7, 15:55 UTCMay 7, 16:10 UTC15m
2026-04-28 N1989B - Apr 28, 20:00 UTCApr 28, 20:50 UTC50m
2026-04-28 N1989B - Apr 28, 16:55 UTCApr 28, 17:10 UTC15m
2026-04-28 N1989B - Apr 28, 14:15 UTCApr 28, 14:55 UTC40m
2026-04-20 N1989B - Apr 20, 16:55 UTCApr 20, 18:30 UTC1h 35m
2026-04-18 N1989B - Apr 18, 18:25 UTCApr 18, 20:10 UTC1h 45m
2026-04-17 N1989B - Apr 17, 23:25 UTCApr 18, 01:20 UTC1h 55m
2026-04-17 N1989B - Apr 17, 22:45 UTCApr 17, 23:20 UTC35m
2026-04-17 N1989B - Apr 17, 21:25 UTCApr 17, 21:40 UTC15m
2026-04-17 N1989B - Apr 17, 20:55 UTCApr 17, 21:20 UTC25m
2026-04-15 N1989B - Apr 15, 19:05 UTCApr 15, 20:55 UTC1h 50m

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 N1989B page for operator, model, and routing details .

Mode-S A18978 frequently asked

What is Mode-S code A18978?
A18978 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N1989B.
Where is Mode-S A18978 registered?
Mode-S code A18978 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 A18978 broadcasting right now?
No active broadcast right now. Last signal was 16d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A18978, octal 50304570, decimal 10,586,488.
What flights does A18978 operate?
Mode-S A18978 has broadcast 1 distinct callsign, including N1989B.