sensors Mode-S transponder

A631E4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N499DT · operated by JEDCO PROPERTIES LLC

Hex
A631E4
Octal
51430744
Decimal
10,891,748
Country
US
Tail
N499DT
Type
E55P
No current signal · last broadcast 17d ago
Flights observed
11
Distinct callsigns
1
Country
US
Last broadcast
17d ago

Last known position

Most recent position reported by Mode-S A631E4.

Country allocation

The ICAO 24-bit address A631E4 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
N499DT - 11 2026-05-20

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-05-20 N499DT - May 20, 02:25 UTCMay 20, 05:00 UTC2h 36m
2026-05-18 N499DT - May 18, 22:00 UTCMay 18, 22:30 UTC30m
2026-05-18 N499DT CUN → MSY May 18, 19:55 UTCMay 18, 21:30 UTC1h 35m
2026-05-14 N499DT - May 14, 14:45 UTCMay 14, 16:40 UTC1h 55m
2026-05-08 N499DT - May 8, 03:09 UTCMay 8, 03:35 UTC25m
2026-05-07 N499DT - May 7, 19:55 UTCMay 7, 20:25 UTC30m
2026-05-02 N499DT - May 2, 18:45 UTCMay 2, 21:05 UTC2h 20m
2026-04-30 N499DT - Apr 30, 19:40 UTCApr 30, 20:30 UTC50m
2026-04-25 N499DT - Apr 25, 20:35 UTCApr 25, 21:30 UTC55m
2026-04-25 N499DT - Apr 25, 19:20 UTCApr 25, 19:55 UTC35m
2026-04-25 N499DT - Apr 25, 13:15 UTCApr 25, 15:10 UTC1h 55m

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 N499DT page for operator, model, and routing details .

Mode-S A631E4 frequently asked

What is Mode-S code A631E4?
A631E4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N499DT.
Where is Mode-S A631E4 registered?
Mode-S code A631E4 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 A631E4 broadcasting right now?
No active broadcast right now. Last signal was 17d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A631E4, octal 51430744, decimal 10,891,748.
What flights does A631E4 operate?
Mode-S A631E4 has broadcast 1 distinct callsign, including N499DT.