sensors Mode-S transponder

A98AC8

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N7139C · PIPER PA-31-300/310/325/350/425 · operated by GV AIR INC

Hex
A98AC8
Octal
52305310
Decimal
11,111,112
Country
US
Tail
N7139C
Type
PA31
No current signal · last broadcast 16h ago
Flights observed
19
Distinct callsigns
2
Country
US
Last broadcast
16h ago

Last known position

Most recent position reported by Mode-S A98AC8.

Country allocation

The ICAO 24-bit address A98AC8 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
UNIFENT - 11 2026-06-08
UNIDENT - 8 2026-07-13

Recent flights last 19

DateFlightRouteTakeoffLandingDuration
2026-07-13 UNIDENT - Jul 13, 07:15 UTCJul 13, 18:15 UTC11h 0m
2026-07-01 UNIDENT - Jul 1, 18:30 UTCJul 1, 23:40 UTC5h 10m
2026-06-29 UNIDENT - Jun 29, 02:30 UTCJun 29, 18:30 UTC16h 0m
2026-06-26 UNIDENT - Jun 26, 21:59 UTCJun 27, 12:45 UTC14h 45m
2026-06-20 UNIDENT - Jun 20, 23:29 UTCJun 21, 12:24 UTC12h 55m
2026-06-20 UNIDENT - Jun 20, 22:20 UTCJun 20, 22:35 UTC15m
2026-06-17 UNIDENT - Jun 17, 23:20 UTCJun 18, 16:20 UTC17h 0m
2026-06-14 UNIDENT - Jun 14, 07:30 UTCJun 14, 20:25 UTC12h 55m
2026-06-08 UNIFENT - Jun 8, 05:00 UTCJun 8, 15:00 UTC10h 0m
2026-06-06 UNIFENT - Jun 6, 20:05 UTCJun 6, 20:30 UTC25m
2026-05-31 UNIFENT - May 31, 18:50 UTCMay 31, 19:00 UTC10m
2026-05-30 UNIFENT - May 30, 04:55 UTCMay 30, 17:00 UTC12h 5m
2026-05-28 UNIFENT - May 28, 12:15 UTCMay 28, 12:55 UTC40m
2026-05-27 UNIFENT - May 27, 00:49 UTCMay 27, 15:40 UTC14h 51m
2026-05-25 UNIFENT - May 25, 05:35 UTCMay 25, 21:15 UTC15h 40m
2026-05-18 UNIFENT - May 18, 20:25 UTCMay 18, 21:35 UTC1h 10m
2026-05-16 UNIFENT - May 16, 04:10 UTCMay 16, 16:10 UTC12h 1m
2026-05-13 UNIFENT - May 13, 07:35 UTCMay 13, 08:30 UTC55m
2026-05-05 UNIFENT - May 5, 05:15 UTCMay 5, 12:30 UTC7h 15m

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 N7139C page for operator, model, and routing details .

Mode-S A98AC8 frequently asked

What is Mode-S code A98AC8?
A98AC8 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N7139C.
Where is Mode-S A98AC8 registered?
Mode-S code A98AC8 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 A98AC8 broadcasting right now?
No active broadcast right now. Last signal was 16h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A98AC8, octal 52305310, decimal 11,111,112.
What flights does A98AC8 operate?
Mode-S A98AC8 has broadcast 2 distinct callsigns, including UNIFENT, UNIDENT.