Apparatus

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sensors Mode-S transponder

A27AAB

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N259TW · operated by TW LEASING LLC

Hex
A27AAB
Octal
50475253
Decimal
10,648,235
Country
US
Tail
N259TW
Type
PC12
Broadcasting now · callsign GPD259 · 4,650 ft
Flights observed
387
Distinct callsigns
1
Country
US
Last broadcast
2h ago

Current position

A27AAB is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A27AAB 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
GPD259 - 387 2026-07-14

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 GPD259 - Jul 14, 14:15 UTCJul 14, 14:45 UTC30m
2026-07-14 GPD259 - Jul 14, 12:40 UTCJul 14, 13:20 UTC40m
2026-07-13 GPD259 - Jul 13, 22:15 UTCJul 13, 23:00 UTC45m
2026-07-13 GPD259 - Jul 13, 20:40 UTCJul 13, 21:20 UTC40m
2026-07-13 GPD259 - Jul 13, 17:05 UTCJul 13, 17:50 UTC45m
2026-07-13 GPD259 - Jul 13, 15:35 UTCJul 13, 16:15 UTC40m
2026-07-13 GPD259 - Jul 13, 13:40 UTCJul 13, 14:20 UTC40m
2026-07-13 GPD259 - Jul 13, 12:25 UTCJul 13, 13:05 UTC40m
2026-07-13 GPD259 - Jul 13, 10:35 UTCJul 13, 11:20 UTC45m
2026-07-13 GPD259 - Jul 13, 09:05 UTCJul 13, 09:45 UTC40m
2026-07-12 GPD259 - Jul 12, 23:45 UTCJul 13, 00:25 UTC40m
2026-07-12 GPD259 - Jul 12, 22:25 UTCJul 12, 23:00 UTC35m
2026-07-12 GPD259 - Jul 12, 20:40 UTCJul 12, 21:20 UTC40m
2026-07-12 GPD259 - Jul 12, 18:50 UTCJul 12, 19:30 UTC40m
2026-07-12 GPD259 - Jul 12, 16:20 UTCJul 12, 17:01 UTC40m
2026-07-12 GPD259 - Jul 12, 14:30 UTCJul 12, 15:01 UTC30m
2026-07-11 GPD259 - Jul 11, 16:05 UTCJul 11, 16:30 UTC25m
2026-07-11 GPD259 - Jul 11, 13:35 UTCJul 11, 14:05 UTC30m
2026-07-11 GPD259 - Jul 11, 00:20 UTCJul 11, 01:05 UTC45m
2026-07-10 GPD259 - Jul 10, 23:05 UTCJul 10, 23:45 UTC40m
2026-07-10 GPD259 - Jul 10, 21:05 UTCJul 10, 21:55 UTC50m
2026-07-10 GPD259 - Jul 10, 19:40 UTCJul 10, 20:25 UTC45m
2026-07-10 GPD259 - Jul 10, 00:50 UTCJul 10, 01:40 UTC50m
2026-07-09 GPD259 - Jul 9, 23:10 UTCJul 10, 00:00 UTC50m
2026-07-09 GPD259 - Jul 9, 20:45 UTCJul 9, 21:45 UTC1h 0m
2026-07-09 GPD259 - Jul 9, 19:30 UTCJul 9, 20:10 UTC40m
2026-07-09 GPD259 - Jul 9, 16:10 UTCJul 9, 18:05 UTC1h 55m
2026-07-09 GPD259 - Jul 9, 14:15 UTCJul 9, 15:05 UTC50m
2026-07-09 GPD259 - Jul 9, 12:40 UTCJul 9, 13:20 UTC40m
2026-07-09 GPD259 - Jul 9, 11:10 UTCJul 9, 11:20 UTC10m
2026-07-09 GPD259 - Jul 9, 00:35 UTCJul 9, 01:15 UTC40m
2026-07-08 GPD259 - Jul 8, 23:05 UTCJul 8, 23:40 UTC35m
2026-07-08 GPD259 - Jul 8, 21:30 UTCJul 8, 22:10 UTC40m
2026-07-08 GPD259 - Jul 8, 19:50 UTCJul 8, 20:25 UTC35m
2026-07-08 GPD259 - Jul 8, 17:35 UTCJul 8, 18:15 UTC40m
2026-07-08 GPD259 - Jul 8, 16:15 UTCJul 8, 16:50 UTC35m
2026-07-07 GPD259 - Jul 7, 21:30 UTCJul 7, 22:15 UTC45m
2026-07-07 GPD259 - Jul 7, 19:45 UTCJul 7, 20:25 UTC40m
2026-07-07 GPD259 - Jul 7, 16:20 UTCJul 7, 18:15 UTC1h 55m
2026-07-07 GPD259 MVY → HPN Jul 7, 14:25 UTCJul 7, 15:10 UTC45m
2026-07-07 GPD259 - Jul 7, 13:05 UTCJul 7, 13:50 UTC45m
2026-07-07 GPD259 - Jul 7, 03:45 UTCJul 7, 04:05 UTC20m
2026-07-07 GPD259 - Jul 7, 01:55 UTCJul 7, 03:00 UTC1h 5m
2026-07-06 GPD259 - Jul 6, 23:45 UTCJul 7, 00:50 UTC1h 5m
2026-07-06 GPD259 - Jul 6, 18:30 UTCJul 6, 19:40 UTC1h 10m
2026-07-06 GPD259 - Jul 6, 17:00 UTCJul 6, 17:50 UTC50m
2026-07-06 GPD259 - Jul 6, 14:55 UTCJul 6, 16:00 UTC1h 5m
2026-07-06 GPD259 - Jul 6, 13:30 UTCJul 6, 14:20 UTC50m
2026-07-06 GPD259 - Jul 6, 10:50 UTCJul 6, 12:05 UTC1h 15m
2026-07-06 GPD259 - Jul 6, 09:35 UTCJul 6, 10:10 UTC35m

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 N259TW page for operator, model, and routing details .

Mode-S A27AAB frequently asked

What is Mode-S code A27AAB?
A27AAB is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N259TW.
Where is Mode-S A27AAB registered?
Mode-S code A27AAB 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 A27AAB broadcasting right now?
Yes. Mode-S A27AAB is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A27AAB, octal 50475253, decimal 10,648,235.
What flights does A27AAB operate?
Mode-S A27AAB has broadcast 1 distinct callsign, including GPD259.