sensors Mode-S transponder

A1B6FF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N20984 · operated by TEXTRON AVIATION INC

Hex
A1B6FF
Octal
50333377
Decimal
10,598,143
Country
US
Tail
N20984
No current signal · last broadcast 20d ago
Flights observed
15
Distinct callsigns
8
Country
US
Last broadcast
20d ago

Last known position

Most recent position reported by Mode-S A1B6FF.

Country allocation

The ICAO 24-bit address A1B6FF 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 8 distinct

Callsign Airline Flights Last seen
BECT179 - 5 2026-06-18
N20984 - 2 2026-06-09
BECT133 - 2 2026-06-10
BECT130 - 2 2026-06-26
BY530 TUI Airways 1 2026-05-15
BECT169 - 1 2026-05-22
BECT157 - 1 2026-06-27
BECT141 - 1 2026-05-20

Recent flights last 15

DateFlightRouteTakeoffLandingDuration
2026-06-27 BECT157 BEC → BEC Jun 27, 19:39 UTCJun 27, 20:39 UTC1h 0m
2026-06-26 BECT130 - Jun 26, 18:24 UTCJun 26, 20:15 UTC1h 50m
2026-06-24 BECT130 BEC → BEC Jun 24, 19:00 UTCJun 24, 20:14 UTC1h 15m
2026-06-18 BECT179 BEC → BEC Jun 18, 20:30 UTCJun 18, 20:55 UTC25m
2026-06-10 BECT133 - Jun 10, 19:40 UTCJun 10, 20:45 UTC1h 5m
2026-06-10 BECT133 BEC → BEC Jun 10, 19:20 UTCJun 10, 19:30 UTC10m
2026-06-09 N20984 - Jun 9, 21:05 UTCJun 9, 21:10 UTC5m
2026-06-09 N20984 - Jun 9, 20:45 UTCJun 9, 20:50 UTC5m
2026-06-08 BECT179 - Jun 8, 21:35 UTCJun 8, 22:10 UTC35m
2026-06-08 BECT179 - Jun 8, 21:20 UTCJun 8, 21:25 UTC5m
2026-06-08 BECT179 BEC → BEC Jun 8, 20:50 UTCJun 8, 21:05 UTC15m
2026-05-22 BECT169 BEC → BEC May 22, 15:35 UTCMay 22, 16:35 UTC1h 0m
2026-05-20 BECT141 - May 20, 17:45 UTCMay 20, 20:10 UTC2h 25m
2026-05-18 BECT179 - May 18, 20:15 UTCMay 18, 21:00 UTC45m
2026-05-15 BY530 MAN → DLM May 15, 12:50 UTCMay 15, 13:00 UTC10m

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 N20984 page for operator, model, and routing details .

Mode-S A1B6FF frequently asked

What is Mode-S code A1B6FF?
A1B6FF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N20984.
Where is Mode-S A1B6FF registered?
Mode-S code A1B6FF 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 A1B6FF broadcasting right now?
No active broadcast right now. Last signal was 20d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A1B6FF, octal 50333377, decimal 10,598,143.
What flights does A1B6FF operate?
Mode-S A1B6FF has broadcast 8 distinct callsigns, including BECT179, N20984, BECT133, BECT130, BY530.