sensors Mode-S transponder

A1435D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N1802U · operated by SOUTHWEST AIRLINES CO

Hex
A1435D
Octal
50241535
Decimal
10,568,541
Country
US
Tail
N1802U
Type
B38M
Broadcasting now · callsign SWA3756 · 40,000 ft
Flights observed
12
Distinct callsigns
9
Country
US
Last broadcast
17h ago

Current position

A1435D is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A1435D 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 9 distinct

Callsign Airline Flights Last seen
SWA785 Southwest Airlines 3 2026-04-13
SWA1249 - 2 2026-04-13
SWA4221 - 1 2026-04-13
SWA4082 - 1 2026-04-12
SWA3093 Southwest Airlines 1 2026-04-13
SWA3021 - 1 2026-04-12
SWA279 - 1 2026-04-13
SWA2076 - 1 2026-04-14
SWA1979 - 1 2026-04-12

Recent flights last 12

DateFlightRouteTakeoffLandingDuration
2026-04-14 SWA2076 - Apr 14, 05:15 UTCApr 14, 05:40 UTC25m
2026-04-13 SWA1249 - Apr 13, 22:58 UTCApr 14, 01:57 UTC2h 59m
2026-04-13 SWA1249 - Apr 13, 23:17 UTCApr 14, 02:00 UTC2h 43m
2026-04-13 SWA279 AUS → ATL Apr 13, 20:07 UTCApr 13, 21:57 UTC1h 50m
2026-04-13 SWA4221 SJC → AUS Apr 13, 16:20 UTCApr 13, 19:15 UTC2h 55m
2026-04-13 SWA3093 BDL → BWI Apr 13, 14:04 UTCApr 13, 15:05 UTC1h 1m
2026-04-13 SWA785 STL → PHL Apr 13, 04:20 UTCApr 13, 05:50 UTC1h 30m
2026-04-13 SWA785 STL → PHL Apr 13, 03:55 UTCApr 13, 05:50 UTC1h 55m
2026-04-13 SWA785 STL → PHL Apr 13, 01:23 UTCApr 13, 05:34 UTC4h 11m
2026-04-12 SWA3021 - Apr 12, 23:55 UTCApr 13, 00:20 UTC25m
2026-04-12 SWA4082 - Apr 12, 18:20 UTCApr 12, 19:34 UTC1h 14m
2026-04-12 SWA1979 SMF → SMF Apr 12, 16:07 UTCApr 12, 17:15 UTC1h 8m

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 N1802U page for operator, model, and routing details .

Mode-S A1435D frequently asked

What is Mode-S code A1435D?
A1435D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N1802U.
Where is Mode-S A1435D registered?
Mode-S code A1435D 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 A1435D broadcasting right now?
Yes. Mode-S A1435D is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A1435D, octal 50241535, decimal 10,568,541.
What flights does A1435D operate?
Mode-S A1435D has broadcast 9 distinct callsigns, including SWA785, SWA1249, SWA4221, SWA4082, SWA3093.