sensors Mode-S transponder

A31E37

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N30NT · AEROSPATIALE AS-350 Ecureuil · operated by CITY OF ONTARIO, POLICE DEPARTMENT AIR SUPPORT UNIT

Hex
A31E37
Octal
50617067
Decimal
10,690,103
Country
US
Tail
N30NT
Type
AS50
No current signal · last broadcast 21h ago
Flights observed
7
Distinct callsigns
2
Country
US
Last broadcast
21h ago

Last known position

Most recent position reported by Mode-S A31E37.

Country allocation

The ICAO 24-bit address A31E37 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
PD20 - 4 2026-04-13
PD30 - 3 2026-04-14

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-14 PD30 ONT → CCB Apr 14, 05:15 UTCApr 14, 06:55 UTC1h 40m
2026-04-13 PD20 - Apr 13, 21:45 UTCApr 13, 22:40 UTC55m
2026-04-13 PD20 - Apr 13, 16:15 UTCApr 13, 16:35 UTC20m
2026-04-13 PD20 - Apr 13, 15:50 UTCApr 13, 16:35 UTC45m
2026-04-13 PD20 - Apr 13, 15:40 UTCApr 13, 16:15 UTC35m
2026-04-13 PD30 - Apr 13, 05:25 UTCApr 13, 06:20 UTC55m
2026-04-13 PD30 - Apr 13, 01:00 UTCApr 13, 02:25 UTC1h 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 N30NT page for operator, model, and routing details .

Mode-S A31E37 frequently asked

What is Mode-S code A31E37?
A31E37 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N30NT.
Where is Mode-S A31E37 registered?
Mode-S code A31E37 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 A31E37 broadcasting right now?
No active broadcast right now. Last signal was 21h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A31E37, octal 50617067, decimal 10,690,103.
What flights does A31E37 operate?
Mode-S A31E37 has broadcast 2 distinct callsigns, including PD20, PD30.