sensors Mode-S transponder

A44240

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N3737C · BOEING 737-800 · operated by DELTA AIR LINES INC

Hex
A44240
Octal
51041100
Decimal
10,764,864
Country
US
Tail
N3737C
Type
B738
No current signal · last broadcast 23h ago
Flights observed
11
Distinct callsigns
6
Country
US
Last broadcast
23h ago

Last known position

Most recent position reported by Mode-S A44240.

Country allocation

The ICAO 24-bit address A44240 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 6 distinct

Callsign Airline Flights Last seen
DAL2993 - 4 2026-04-13
DAL2897 - 2 2026-04-13
DAL2214 - 2 2026-04-13
DAL678 - 1 2026-04-12
DAL355 - 1 2026-04-13
DAL1672 - 1 2026-04-13

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-13 DAL355 - Apr 13, 20:17 UTCApr 14, 00:09 UTC3h 52m
2026-04-13 DAL2214 - Apr 13, 16:30 UTCApr 13, 18:45 UTC2h 15m
2026-04-13 DAL2214 - Apr 13, 15:57 UTCApr 13, 18:47 UTC2h 50m
2026-04-13 DAL2897 HDE → SLC Apr 13, 12:20 UTCApr 13, 14:05 UTC1h 45m
2026-04-13 DAL2897 - Apr 13, 11:45 UTCApr 13, 12:15 UTC30m
2026-04-13 DAL2993 - Apr 13, 04:20 UTCApr 13, 05:15 UTC55m
2026-04-13 DAL2993 - Apr 13, 04:00 UTCApr 13, 05:15 UTC1h 15m
2026-04-13 DAL2993 - Apr 13, 03:37 UTCApr 13, 05:30 UTC1h 53m
2026-04-13 DAL2993 - Apr 13, 03:26 UTCApr 13, 05:20 UTC1h 54m
2026-04-13 DAL1672 - Apr 13, 00:20 UTCApr 13, 01:10 UTC50m
2026-04-12 DAL678 - Apr 12, 17:15 UTCApr 12, 19:25 UTC2h 10m

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 N3737C page for operator, model, and routing details .

Mode-S A44240 frequently asked

What is Mode-S code A44240?
A44240 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N3737C.
Where is Mode-S A44240 registered?
Mode-S code A44240 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 A44240 broadcasting right now?
No active broadcast right now. Last signal was 23h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A44240, octal 51041100, decimal 10,764,864.
What flights does A44240 operate?
Mode-S A44240 has broadcast 6 distinct callsigns, including DAL2993, DAL2897, DAL2214, DAL678, DAL355.