sensors Mode-S transponder

ADF0FF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N998GP · GULFSTREAM 4 · operated by AIR MCCORMACK2 LLC

Hex
ADF0FF
Octal
53370377
Decimal
11,399,423
Country
US
Tail
N998GP
Type
GLF4
No current signal · last broadcast 1d ago
Flights observed
7
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S ADF0FF.

Country allocation

The ICAO 24-bit address ADF0FF 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
N998GP - 7 2026-04-13

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-13 N998GP - Apr 13, 08:20 UTCApr 13, 11:15 UTC2h 55m
2026-04-13 N998GP - Apr 13, 07:55 UTCApr 13, 11:15 UTC3h 20m
2026-04-13 N998GP - Apr 13, 06:05 UTCApr 13, 08:15 UTC2h 10m
2026-04-13 N998GP - Apr 13, 04:20 UTCApr 13, 05:10 UTC50m
2026-04-13 N998GP - Apr 13, 03:55 UTCApr 13, 05:10 UTC1h 15m
2026-04-13 N998GP - Apr 13, 03:00 UTCApr 13, 04:15 UTC1h 15m
2026-04-12 N998GP IAD → TEB Apr 12, 19:20 UTCApr 12, 20:15 UTC55m

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 N998GP page for operator, model, and routing details .

Mode-S ADF0FF frequently asked

What is Mode-S code ADF0FF?
ADF0FF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N998GP.
Where is Mode-S ADF0FF registered?
Mode-S code ADF0FF 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 ADF0FF broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex ADF0FF, octal 53370377, decimal 11,399,423.
What flights does ADF0FF operate?
Mode-S ADF0FF has broadcast 1 distinct callsign, including N998GP.