sensors Mode-S transponder

A9D651

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N733BH · SWEARINGEN Metro · operated by CAREER AVIATION COMPANY INC

Hex
A9D651
Octal
52353121
Decimal
11,130,449
Country
US
Tail
N733BH
Type
SW4
No current signal · last broadcast 19h ago
Flights observed
6
Distinct callsigns
2
Country
US
Last broadcast
19h ago

Last known position

Most recent position reported by Mode-S A9D651.

Country allocation

The ICAO 24-bit address A9D651 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
PKW1057 - 5 2026-04-17
PKW988 - 1 2026-04-14

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-17 PKW1057 - Apr 17, 23:40 UTCApr 18, 00:20 UTC40m
2026-04-17 PKW1057 - Apr 17, 19:50 UTCApr 17, 21:20 UTC1h 30m
2026-04-16 PKW1057 - Apr 16, 07:09 UTCApr 16, 08:19 UTC1h 10m
2026-04-16 PKW1057 - Apr 16, 05:29 UTCApr 16, 07:05 UTC1h 35m
2026-04-16 PKW1057 - Apr 16, 03:09 UTCApr 16, 04:54 UTC1h 45m
2026-04-14 PKW988 - Apr 14, 05:15 UTCApr 14, 06:20 UTC1h 5m

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 N733BH page for operator, model, and routing details .

Mode-S A9D651 frequently asked

What is Mode-S code A9D651?
A9D651 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N733BH.
Where is Mode-S A9D651 registered?
Mode-S code A9D651 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 A9D651 broadcasting right now?
No active broadcast right now. Last signal was 19h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A9D651, octal 52353121, decimal 11,130,449.
What flights does A9D651 operate?
Mode-S A9D651 has broadcast 2 distinct callsigns, including PKW1057, PKW988.