sensors Mode-S transponder

A5281A

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N431P · BELL 407 · operated by PHI HEALTH LLC

Hex
A5281A
Octal
51224032
Decimal
10,823,706
Country
US
Tail
N431P
Type
B407
Broadcasting now · callsign N431P · 2,500 ft
Flights observed
10
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Current position

A5281A is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A5281A 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
N431P - 10 2026-04-13

Recent flights last 10

DateFlightRouteTakeoffLandingDuration
2026-04-13 N431P - Apr 13, 09:05 UTCApr 13, 09:30 UTC25m
2026-04-13 N431P - Apr 13, 07:45 UTCApr 13, 08:15 UTC30m
2026-04-13 N431P - Apr 13, 06:00 UTCApr 13, 06:20 UTC19m
2026-04-13 N431P - Apr 13, 04:20 UTCApr 13, 04:30 UTC10m
2026-04-13 N431P - Apr 13, 02:15 UTCApr 13, 02:40 UTC25m
2026-04-13 N431P - Apr 13, 01:15 UTCApr 13, 01:45 UTC30m
2026-04-13 N431P - Apr 13, 00:30 UTCApr 13, 00:40 UTC10m
2026-04-12 N431P - Apr 12, 19:00 UTCApr 12, 19:30 UTC30m
2026-04-12 N431P - Apr 12, 18:15 UTCApr 12, 18:30 UTC15m
2026-04-12 N431P - Apr 12, 17:25 UTCApr 12, 17:45 UTC20m

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 N431P page for operator, model, and routing details .

Mode-S A5281A frequently asked

What is Mode-S code A5281A?
A5281A is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N431P.
Where is Mode-S A5281A registered?
Mode-S code A5281A 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 A5281A broadcasting right now?
Yes. Mode-S A5281A is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A5281A, octal 51224032, decimal 10,823,706.
What flights does A5281A operate?
Mode-S A5281A has broadcast 1 distinct callsign, including N431P.