sensors Mode-S transponder

A631BB

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N499CB · PILATUS PC-12 · operated by 3 T CAPITAL LLC, SUNCREST HEALTH SERVICES LLC, RUECO LLC, LEIGHTON TRACE AND WENDY, IROLLIE MARKETING LLC, INTERGRITY 1ST LLC

Hex
A631BB
Octal
51430673
Decimal
10,891,707
Country
US
Tail
N499CB
Type
PC12
No current signal · last broadcast 23h ago
Flights observed
7
Distinct callsigns
1
Country
US
Last broadcast
23h ago

Last known position

Most recent position reported by Mode-S A631BB.

Country allocation

The ICAO 24-bit address A631BB 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
CBC499 - 7 2026-04-17

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-17 CBC499 - Apr 17, 18:35 UTCApr 17, 19:20 UTC45m
2026-04-16 CBC499 - Apr 16, 19:20 UTCApr 16, 20:00 UTC40m
2026-04-16 CBC499 - Apr 16, 17:15 UTCApr 16, 17:35 UTC20m
2026-04-15 CBC499 - Apr 15, 22:45 UTCApr 15, 23:00 UTC15m
2026-04-14 CBC499 - Apr 14, 23:10 UTCApr 14, 23:25 UTC15m
2026-04-14 CBC499 - Apr 14, 13:40 UTCApr 14, 13:55 UTC15m
2026-04-12 CBC499 - Apr 12, 17:55 UTCApr 12, 18:20 UTC25m

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 N499CB page for operator, model, and routing details .

Mode-S A631BB frequently asked

What is Mode-S code A631BB?
A631BB is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N499CB.
Where is Mode-S A631BB registered?
Mode-S code A631BB 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 A631BB broadcasting right now?
No active broadcast right now. Last signal was 23h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A631BB, octal 51430673, decimal 10,891,707.
What flights does A631BB operate?
Mode-S A631BB has broadcast 1 distinct callsign, including CBC499.