sensors Mode-S transponder

A6681D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N5114U · CESSNA 172R Cutlass RG · operated by SILVERHAWK AVIATION ACADEMY LLC

Hex
A6681D
Octal
51464035
Decimal
10,905,629
Country
US
Tail
N5114U
Type
C72R
No current signal · last broadcast 1h ago
Flights observed
9
Distinct callsigns
1
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S A6681D.

Country allocation

The ICAO 24-bit address A6681D 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
N5114U - 9 2026-04-18

Recent flights last 9

DateFlightRouteTakeoffLandingDuration
2026-04-18 N5114U - Apr 18, 16:55 UTCApr 18, 17:55 UTC1h 0m
2026-04-18 N5114U - Apr 18, 15:55 UTCApr 18, 16:15 UTC20m
2026-04-18 N5114U - Apr 18, 12:55 UTCApr 18, 13:25 UTC30m
2026-04-17 N5114U - Apr 17, 21:30 UTCApr 17, 21:45 UTC15m
2026-04-17 N5114U - Apr 17, 20:45 UTCApr 17, 21:20 UTC35m
2026-04-17 N5114U - Apr 17, 16:30 UTCApr 17, 16:55 UTC25m
2026-04-17 N5114U - Apr 17, 13:35 UTCApr 17, 13:55 UTC20m
2026-04-14 N5114U - Apr 14, 17:40 UTCApr 14, 17:55 UTC15m
2026-04-14 N5114U - Apr 14, 16:50 UTCApr 14, 17:05 UTC15m

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 N5114U page for operator, model, and routing details .

Mode-S A6681D frequently asked

What is Mode-S code A6681D?
A6681D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N5114U.
Where is Mode-S A6681D registered?
Mode-S code A6681D 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 A6681D broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A6681D, octal 51464035, decimal 10,905,629.
What flights does A6681D operate?
Mode-S A6681D has broadcast 1 distinct callsign, including N5114U.