sensors Mode-S transponder

A3901D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N329DU · operated by DELTA AIR LINES INC, DEPT 595 AIRCRAFT REGISTRATIONS

Hex
A3901D
Octal
50710035
Decimal
10,719,261
Country
US
Tail
N329DU
Type
BCS3
Broadcasting now · callsign DAL2521 · 36,000 ft
Flights observed
432
Distinct callsigns
20
Country
US
Last broadcast
51m ago

Current position

A3901D is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A3901D 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 20 distinct

Callsign Airline Flights Last seen
DAL483 - 14 2026-06-24
DAL1602 Delta Air Lines 11 2026-04-28
DAL1412 - 11 2026-06-14
DAL1297 - 11 2026-07-01
DAL2549 - 10 2026-06-25
DAL1358 - 9 2026-06-22
DAL2917 Delta Air Lines 8 2026-04-28
DAL1417 - 8 2026-06-19
DAL2140 - 7 2026-07-05
DAL1567 - 7 2026-07-12
DAL1404 - 7 2026-06-19
DAL922 Delta Air Lines 6 2026-05-18
DAL856 Delta Air Lines 6 2026-05-04
DAL831 Delta Air Lines 6 2026-05-25
DAL2851 - 6 2026-06-28
DAL1061 - 6 2026-06-25
DAL1015 Delta Air Lines 6 2026-06-25
DAL739 - 5 2026-06-29
DAL541 - 5 2026-06-22
DAL303 - 5 2026-06-20

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 DAL2521 - Jul 14, 18:55 UTCJul 14, 19:15 UTC20m
2026-07-14 DAL2521 - Jul 14, 15:30 UTCJul 14, 17:40 UTC2h 10m
2026-07-14 DAL2717 SAT → MSP Jul 14, 11:35 UTCJul 14, 14:00 UTC2h 25m
2026-07-14 DAL2773 MSP → SAT Jul 14, 01:40 UTCJul 14, 04:00 UTC2h 20m
2026-07-13 DAL1306 ORD → MSP Jul 13, 23:30 UTCJul 14, 00:25 UTC55m
2026-07-13 DAL1306 ORD → MSP Jul 13, 23:30 UTCJul 14, 00:22 UTC52m
2026-07-13 DAL1306 MSP → ORD Jul 13, 20:50 UTCJul 13, 22:10 UTC1h 20m
2026-07-13 DAL2958 DCA → MSP Jul 13, 17:20 UTCJul 13, 19:20 UTC2h 0m
2026-07-13 DAL2958 DCA → MSP Jul 13, 17:17 UTCJul 13, 19:19 UTC2h 2m
2026-07-13 DAL2958 MSP → DCA Jul 13, 12:45 UTCJul 13, 14:50 UTC2h 5m
2026-07-12 DAL1567 - Jul 12, 17:35 UTCJul 12, 18:30 UTC55m
2026-07-12 DAL1567 - Jul 12, 15:20 UTCJul 12, 16:15 UTC55m
2026-07-12 DAL2717 - Jul 12, 11:15 UTCJul 12, 13:50 UTC2h 35m
2026-07-11 DAL2773 - Jul 11, 23:40 UTCJul 12, 02:10 UTC2h 30m
2026-07-11 DAL2332 ATL → MCI Jul 11, 18:35 UTCJul 11, 20:30 UTC1h 55m
2026-07-11 DAL2332 ATL → MCI Jul 11, 14:35 UTCJul 11, 16:45 UTC2h 10m
2026-07-11 DAL2913 - Jul 11, 11:10 UTCJul 11, 12:15 UTC1h 5m
2026-07-11 DAL1711 MSP → GRR Jul 11, 02:55 UTCJul 11, 03:55 UTC1h 0m
2026-07-10 DAL2617 - Jul 10, 22:50 UTCJul 11, 01:05 UTC2h 15m
2026-07-10 DAL2930 - Jul 10, 18:15 UTCJul 10, 21:35 UTC3h 20m
2026-07-10 DAL2930 LGA → IAH Jul 10, 18:13 UTCJul 10, 21:38 UTC3h 25m
2026-07-10 DAL2252 - Jul 10, 14:45 UTCJul 10, 16:20 UTC1h 35m
2026-07-10 DAL1544 - Jul 10, 12:10 UTCJul 10, 13:15 UTC1h 5m
2026-07-10 DAL2617 - Jul 10, 04:00 UTCJul 10, 06:20 UTC2h 20m
2026-07-09 DAL2930 - Jul 9, 23:15 UTCJul 10, 02:25 UTC3h 10m
2026-07-09 DAL2930 - Jul 9, 19:25 UTCJul 9, 20:00 UTC35m
2026-07-09 DAL2252 - Jul 9, 16:00 UTCJul 9, 17:55 UTC1h 55m
2026-07-09 DAL1544 - Jul 9, 13:25 UTCJul 9, 14:40 UTC1h 15m
2026-07-09 DAL2913 - Jul 9, 11:10 UTCJul 9, 12:10 UTC1h 0m
2026-07-09 DAL1711 MSP → GRR Jul 9, 02:55 UTCJul 9, 04:05 UTC1h 10m
2026-07-08 DAL703 - Jul 8, 23:45 UTCJul 9, 01:15 UTC1h 30m
2026-07-08 DAL703 MSP → CVG Jul 8, 21:05 UTCJul 8, 22:45 UTC1h 40m
2026-07-08 DAL1567 - Jul 8, 17:35 UTCJul 8, 18:35 UTC1h 0m
2026-07-08 DAL1567 ORD → MSP Jul 8, 17:34 UTCJul 8, 18:34 UTC1h 0m
2026-07-08 DAL1567 - Jul 8, 15:20 UTCJul 8, 16:15 UTC55m
2026-07-08 DAL2717 - Jul 8, 11:15 UTCJul 8, 13:40 UTC2h 25m
2026-07-07 DAL2773 - Jul 7, 23:45 UTCJul 8, 02:05 UTC2h 20m
2026-07-07 DAL2679 PHL → MSP Jul 7, 19:50 UTCJul 7, 22:20 UTC2h 30m
2026-07-07 DAL2679 MSP → PHL Jul 7, 16:20 UTCJul 7, 18:25 UTC2h 5m
2026-07-07 DAL1554 - Jul 7, 13:45 UTCJul 7, 14:40 UTC55m
2026-07-07 DAL1554 ORD → MSP Jul 7, 13:44 UTCJul 7, 14:41 UTC57m
2026-07-07 DAL2251 DTW → BDL Jul 7, 10:10 UTCJul 7, 12:00 UTC1h 50m
2026-07-07 DAL2445 DTW → CMH Jul 7, 02:25 UTCJul 7, 05:20 UTC2h 55m
2026-07-06 DAL1387 JFK → MSY Jul 6, 22:10 UTCJul 7, 00:55 UTC2h 45m
2026-07-06 DAL1394 - Jul 6, 18:45 UTCJul 6, 20:05 UTC1h 20m
2026-07-06 DAL1394 CMH → JFK Jul 6, 18:41 UTCJul 6, 20:01 UTC1h 20m
2026-07-06 DAL1394 MSY → CMH Jul 6, 01:45 UTCJul 6, 04:50 UTC3h 5m
2026-07-06 DAL1394 MSY → CMH Jul 6, 01:40 UTCJul 6, 04:50 UTC3h 10m
2026-07-05 DAL2405 LGA → MSY Jul 5, 20:50 UTCJul 5, 23:30 UTC2h 40m
2026-07-05 DAL2140 - Jul 5, 16:05 UTCJul 5, 19:05 UTC3h 0m

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 N329DU page for operator, model, and routing details .

Mode-S A3901D frequently asked

What is Mode-S code A3901D?
A3901D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N329DU.
Where is Mode-S A3901D registered?
Mode-S code A3901D 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 A3901D broadcasting right now?
Yes. Mode-S A3901D is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A3901D, octal 50710035, decimal 10,719,261.
What flights does A3901D operate?
Mode-S A3901D has broadcast 20 distinct callsigns, including DAL483, DAL1602, DAL1412, DAL1297, DAL2549.