sensors Mode-S transponder

A39D9B

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N332DU · operated by DELTA AIR LINES INC

Hex
A39D9B
Octal
50716633
Decimal
10,722,715
Country
US
Tail
N332DU
Type
BCS3
Transponder active on ground
Flights observed
253
Distinct callsigns
20
Country
US
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S A39D9B.

Country allocation

The ICAO 24-bit address A39D9B 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

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 DAL1630 ATL → EWR May 29, 20:35 UTCMay 29, 21:35 UTC1h 0m
2026-05-29 DAL2808 BOI → MSP May 29, 14:20 UTCMay 29, 16:40 UTC2h 20m
2026-05-29 DAL2488 BOS → RDU May 29, 03:00 UTCMay 29, 05:30 UTC2h 30m
2026-05-28 DAL2617 BOS → JFK May 28, 23:10 UTCMay 29, 01:25 UTC2h 15m
2026-05-28 DAL2930 MSP → LGA May 28, 18:50 UTCMay 28, 22:05 UTC3h 15m
2026-05-28 DAL2194 BDL → ATL May 28, 15:15 UTCMay 28, 16:35 UTC1h 20m
2026-05-28 DAL2194 BDL → ATL May 28, 15:09 UTCMay 28, 16:26 UTC1h 17m
2026-05-28 DAL2194 BDL → ATL May 28, 12:35 UTCMay 28, 13:55 UTC1h 20m
2026-05-28 DAL2426 EWR → MSP May 28, 00:55 UTCMay 28, 03:35 UTC2h 40m
2026-05-27 DAL1387 BOS → RDU May 27, 20:25 UTCMay 27, 23:40 UTC3h 15m
2026-05-27 DAL1529 TPA → DTW May 27, 15:35 UTCMay 27, 18:35 UTC3h 0m
2026-05-27 DAL1529 TPA → DTW May 27, 15:32 UTCMay 27, 18:31 UTC2h 59m
2026-05-27 DAL2310 SFO → SEA May 27, 11:25 UTCMay 27, 14:20 UTC2h 55m
2026-05-27 DAL2310 SFO → SEA May 27, 01:29 UTCMay 27, 03:50 UTC2h 20m
2026-05-26 DAL2310 SFO → SEA May 26, 21:25 UTCMay 27, 00:14 UTC2h 50m
2026-05-26 DAL572 ATL → BOS May 26, 16:24 UTCMay 26, 18:45 UTC2h 20m
2026-05-26 DAL572 ATL → BOS May 26, 11:50 UTCMay 26, 14:24 UTC2h 35m
2026-05-26 DAL2068 RDU → BOS May 26, 00:19 UTCMay 26, 02:35 UTC2h 15m
2026-05-25 DAL2068 RDU → BOS May 25, 20:19 UTCMay 25, 23:00 UTC2h 40m
2026-05-25 DAL379 ATL → LGA May 25, 15:55 UTCMay 25, 18:30 UTC2h 35m
2026-05-25 DAL379 ATL → LGA May 25, 11:45 UTCMay 25, 14:45 UTC3h 0m
2026-05-25 DAL2310 SFO → SEA May 25, 01:55 UTCMay 25, 02:10 UTC15m
2026-05-24 DAL2310 SFO → SEA May 24, 19:55 UTCMay 24, 21:45 UTC1h 50m
2026-05-24 DAL572 ATL → BOS May 24, 15:55 UTCMay 24, 18:15 UTC2h 20m
2026-05-24 DAL2097 MSP → LAS May 24, 11:45 UTCMay 24, 14:25 UTC2h 40m
2026-05-24 DAL2097 MSP → LAS May 24, 02:00 UTCMay 24, 04:50 UTC2h 50m
2026-05-24 DAL2097 MSP → LAS May 24, 01:58 UTCMay 24, 04:46 UTC2h 48m
2026-05-23 DAL2673 PVD → ATL May 23, 18:10 UTCMay 23, 20:50 UTC2h 40m
2026-05-23 DAL1493 DCA → MSP May 23, 12:00 UTCMay 23, 14:10 UTC2h 10m
2026-05-23 DAL1071 ATL → AVL May 23, 03:45 UTCMay 23, 04:35 UTC50m
2026-05-23 DAL2788 PWM → ATL May 23, 00:25 UTCMay 23, 02:15 UTC1h 50m
2026-05-22 DAL1710 JFK → SAT May 22, 16:25 UTCMay 22, 20:30 UTC4h 5m
2026-05-22 DAL1731 DEN → SEA May 22, 12:15 UTCMay 22, 14:45 UTC2h 30m
2026-05-22 DAL1731 DEN → SEA May 22, 12:14 UTCMay 22, 14:46 UTC2h 32m
2026-05-22 DAL2851 YUL → ATL May 22, 03:20 UTCMay 22, 05:35 UTC2h 15m
2026-05-21 DAL803 LAX → SEA May 21, 21:30 UTCMay 22, 01:25 UTC3h 55m
2026-05-21 DAL803 LAX → SEA May 21, 16:35 UTCMay 21, 20:00 UTC3h 25m
2026-05-21 DAL2721 DAY → ATL May 21, 13:01 UTCMay 21, 14:40 UTC1h 40m
2026-05-21 DAL2721 DAY → ATL May 21, 12:59 UTCMay 21, 14:41 UTC1h 42m
2026-05-21 DAL2635 MSP → PIT May 21, 05:20 UTCMay 21, 06:55 UTC1h 35m
2026-05-20 DAL1705 PHX → JFK May 20, 21:40 UTCMay 21, 02:15 UTC4h 35m
2026-05-20 DAL2748 MSP → FSD May 20, 18:10 UTCMay 20, 20:10 UTC2h 0m
2026-05-20 DAL2271 CVG → RSW May 20, 15:15 UTCMay 20, 16:45 UTC1h 30m
2026-05-20 DAL1544 ATL → PBI May 20, 12:01 UTCMay 20, 13:09 UTC1h 8m
2026-05-20 DAL2138 ATL → PWM May 20, 12:05 UTCMay 20, 13:05 UTC1h 0m
2026-05-20 DAL2138 ATL → PWM May 20, 04:15 UTCMay 20, 05:10 UTC56m
2026-05-20 DAL2138 ATL → PWM May 20, 04:10 UTCMay 20, 05:06 UTC56m
2026-05-20 DAL2503 SAN → SEA May 20, 00:55 UTCMay 20, 03:10 UTC2h 15m
2026-05-19 DAL2412 LAX → SFO May 19, 18:35 UTCMay 19, 21:05 UTC2h 30m
2026-05-19 DAL2412 LAX → SFO May 19, 14:35 UTCMay 19, 16:55 UTC2h 20m

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 N332DU page for operator, model, and routing details .

Mode-S A39D9B frequently asked

What is Mode-S code A39D9B?
A39D9B is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N332DU.
Where is Mode-S A39D9B registered?
Mode-S code A39D9B 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 A39D9B broadcasting right now?
Mode-S A39D9B is currently broadcasting from the ground.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A39D9B, octal 50716633, decimal 10,722,715.
What flights does A39D9B operate?
Mode-S A39D9B has broadcast 20 distinct callsigns, including DAL2140, DAL716, DAL2310, DAL2910, DAL1493.