sensors Mode-S transponder

AB39DF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N822SF · operated by IATS

Hex
AB39DF
Octal
52634737
Decimal
11,221,471
Country
US
Tail
N822SF
No current signal · last broadcast 3d ago
Flights observed
13
Distinct callsigns
1
Country
US
Last broadcast
3d ago

Last known position

Most recent position reported by Mode-S AB39DF.

Country allocation

The ICAO 24-bit address AB39DF 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
TWY822 - 13 2026-05-17

Recent flights last 13

DateFlightRouteTakeoffLandingDuration
2026-05-17 TWY822 COS → TEB May 17, 20:35 UTCMay 17, 23:35 UTC3h 0m
2026-05-15 TWY822 TEB → COS May 15, 16:20 UTCMay 15, 19:35 UTC3h 15m
2026-05-10 TWY822 - May 10, 16:55 UTCMay 10, 21:30 UTC4h 35m
2026-05-10 TWY822 - May 10, 15:09 UTCMay 10, 16:25 UTC1h 15m
2026-05-02 TWY822 - May 2, 01:40 UTCMay 2, 02:35 UTC55m
2026-05-02 TWY822 OAK → LAX May 2, 00:00 UTCMay 2, 00:55 UTC55m
2026-04-27 TWY822 - Apr 27, 01:00 UTCApr 27, 01:55 UTC55m
2026-04-26 TWY822 - Apr 26, 22:20 UTCApr 26, 23:20 UTC1h 0m
2026-04-23 TWY822 - Apr 23, 12:05 UTCApr 23, 18:35 UTC6h 29m
2026-04-21 TWY822 - Apr 21, 20:05 UTCApr 21, 21:05 UTC1h 0m
2026-04-21 TWY822 - Apr 21, 17:20 UTCApr 21, 17:40 UTC20m
2026-04-20 TWY822 - Apr 20, 00:45 UTCApr 20, 01:40 UTC55m
2026-04-12 TWY822 - Apr 12, 17:50 UTCApr 12, 20:15 UTC2h 25m

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 N822SF page for operator, model, and routing details .

Mode-S AB39DF frequently asked

What is Mode-S code AB39DF?
AB39DF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N822SF.
Where is Mode-S AB39DF registered?
Mode-S code AB39DF 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 AB39DF broadcasting right now?
No active broadcast right now. Last signal was 3d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AB39DF, octal 52634737, decimal 11,221,471.
What flights does AB39DF operate?
Mode-S AB39DF has broadcast 1 distinct callsign, including TWY822.