sensors Mode-S transponder

A445B0

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N3745B · BOEING 737-800 · operated by DELTA AIR LINES INC

Hex
A445B0
Octal
51042660
Decimal
10,765,744
Country
US
Tail
N3745B
Type
B738
No current signal · last broadcast 23h ago
Flights observed
5
Distinct callsigns
5
Country
US
Last broadcast
23h ago

Last known position

Most recent position reported by Mode-S A445B0.

Country allocation

The ICAO 24-bit address A445B0 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 5 distinct

Callsign Airline Flights Last seen
DAL609 - 1 2026-04-13
DAL1987 Delta Air Lines 1 2026-04-13
DAL1949 - 1 2026-04-13
DAL1939 - 1 2026-04-13
DAL1928 - 1 2026-04-12

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-13 DAL1987 MBJ → ATL Apr 13, 21:44 UTCApr 14, 00:17 UTC2h 33m
2026-04-13 DAL1949 - Apr 13, 17:39 UTCApr 13, 19:58 UTC2h 19m
2026-04-13 DAL609 - Apr 13, 13:03 UTCApr 13, 15:07 UTC2h 4m
2026-04-13 DAL1939 - Apr 13, 00:30 UTCApr 13, 00:40 UTC10m
2026-04-12 DAL1928 - Apr 12, 19:30 UTCApr 12, 20:15 UTC45m

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 N3745B page for operator, model, and routing details .

Mode-S A445B0 frequently asked

What is Mode-S code A445B0?
A445B0 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N3745B.
Where is Mode-S A445B0 registered?
Mode-S code A445B0 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 A445B0 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 A445B0, octal 51042660, decimal 10,765,744.
What flights does A445B0 operate?
Mode-S A445B0 has broadcast 5 distinct callsigns, including DAL609, DAL1987, DAL1949, DAL1939, DAL1928.