Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A399DE

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N331DN · AIRBUS A-321 · operated by BANK OF UTAH TRUSTEE

Hex
A399DE
Octal
50714736
Decimal
10,721,758
Country
US
Tail
N331DN
Type
A321
No current signal · last broadcast Jul 26, 20:05 UTC
Flights observed
576
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 20:05 UTC

Last known position

Most recent position reported by Mode-S A399DE.

Country allocation

The ICAO 24-bit address A399DE 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
DAL838 - 9 2026-07-20
DAL598 - 8 2026-07-04
DAL2886 - 8 2026-07-15
DAL2593 Delta Air Lines 8 2026-06-04
DAL1527 Delta Air Lines 8 2026-06-12
DAL726 Delta Air Lines 7 2026-06-09
DAL655 - 7 2026-07-17
DAL597 - 7 2026-07-04
DAL2649 Delta Air Lines 7 2026-06-03
DAL1397 - 7 2026-06-26
DAL1180 Delta Air Lines 7 2026-07-25
DAL1151 - 7 2026-07-08
DAL2950 - 6 2026-06-14
DAL2590 - 6 2026-06-27
DAL1384 Delta Air Lines 6 2026-05-14
DAL1323 Delta Air Lines 6 2026-06-10
DAL1169 - 6 2026-06-23
DAL641 Delta Air Lines 5 2026-07-26
DAL374 - 5 2026-06-30
DAL2923 Delta Air Lines 5 2026-05-26

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 DAL641 CUN → ATL Jul 26, 17:45 UTCJul 26, 20:00 UTC2h 15m
2026-07-26 DAL586 ATL → CUN Jul 26, 14:00 UTCJul 26, 16:05 UTC2h 5m
2026-07-26 DAL2353 EWR → ATL Jul 26, 10:15 UTCJul 26, 12:00 UTC1h 45m
2026-07-26 DAL2498 LGA → DTW Jul 26, 00:35 UTCJul 26, 02:25 UTC1h 50m
2026-07-25 DAL2131 BOS → TPA Jul 25, 19:50 UTCJul 25, 21:25 UTC1h 35m
2026-07-25 DAL2131 BOS → TPA Jul 25, 16:50 UTCJul 25, 18:25 UTC1h 35m
2026-07-25 DAL1180 LAS → CVG Jul 25, 13:55 UTCJul 25, 15:25 UTC1h 30m
2026-07-25 DAL2642 ATL → PHL Jul 25, 03:25 UTCJul 25, 04:55 UTC1h 30m
2026-07-24 DAL1491 CHS → BOS Jul 24, 23:50 UTCJul 25, 01:45 UTC1h 55m
2026-07-24 DAL1491 CHS → BOS Jul 24, 23:47 UTCJul 25, 01:38 UTC1h 51m
2026-07-24 DAL1491 CHS → BOS Jul 24, 20:35 UTCJul 24, 22:25 UTC1h 50m
2026-07-24 DAL664 SFO → JFK Jul 24, 17:30 UTCJul 24, 18:50 UTC1h 20m
2026-07-24 DAL664 SFO → JFK Jul 24, 17:26 UTCJul 24, 18:53 UTC1h 27m
2026-07-24 DAL664 SFO → JFK Jul 24, 15:05 UTCJul 24, 16:10 UTC1h 5m
2026-07-24 DAL1673 MIA → BOS Jul 24, 13:30 UTCJul 24, 13:35 UTC5m
2026-07-24 DAL1673 MIA → BOS Jul 24, 11:26 UTCJul 24, 13:15 UTC1h 49m
2026-07-24 DAL1673 MIA → BOS Jul 24, 11:30 UTCJul 24, 13:30 UTC2h 0m
2026-07-24 DAL2527 ATL → EWR Jul 24, 00:40 UTCJul 24, 02:25 UTC1h 45m
2026-07-23 DAL1919 PUJ → ATL Jul 23, 14:30 UTCJul 23, 22:20 UTC7h 50m
2026-07-23 DAL2662 YYZ → ATL Jul 23, 10:10 UTCJul 23, 11:50 UTC1h 40m
2026-07-23 DAL2422 JFK → PHX Jul 23, 01:50 UTCJul 23, 03:40 UTC1h 50m
2026-07-22 DAL1150 MCO → ATL Jul 22, 22:20 UTCJul 22, 23:25 UTC1h 5m
2026-07-22 DAL1150 ATL → MCO Jul 22, 19:15 UTCJul 22, 20:15 UTC1h 0m
2026-07-22 DAL1510 - Jul 22, 16:20 UTCJul 22, 17:40 UTC1h 20m
2026-07-22 DAL1510 - Jul 22, 13:10 UTCJul 22, 14:35 UTC1h 25m
2026-07-22 DAL1376 SEA → JFK Jul 22, 10:04 UTCJul 22, 11:21 UTC1h 17m
2026-07-22 DAL1065 DTW → PBI Jul 22, 05:00 UTCJul 22, 11:25 UTC6h 25m
2026-07-22 DAL488 MCO → MSP Jul 22, 00:10 UTCJul 22, 02:40 UTC2h 30m
2026-07-21 DAL488 MCO → MSP Jul 21, 20:05 UTCJul 21, 22:20 UTC2h 15m
2026-07-21 DAL761 TPA → LGA Jul 21, 14:15 UTCJul 21, 18:10 UTC3h 55m
2026-07-21 DAL761 TPA → LGA Jul 21, 14:12 UTCJul 21, 18:10 UTC3h 58m
2026-07-21 DAL779 BOS → MSP Jul 21, 00:45 UTCJul 21, 04:35 UTC3h 50m
2026-07-20 DAL838 - Jul 20, 21:50 UTCJul 20, 23:15 UTC1h 25m
2026-07-20 DAL838 - Jul 20, 18:20 UTCJul 20, 19:45 UTC1h 25m
2026-07-20 DAL1627 DFW → ATL Jul 20, 13:35 UTCJul 20, 15:20 UTC1h 45m
2026-07-19 DAL436 ATL → DFW Jul 19, 23:55 UTCJul 20, 01:40 UTC1h 45m
2026-07-19 DAL1341 JFK → MIA Jul 19, 20:50 UTCJul 19, 22:10 UTC1h 20m
2026-07-19 DAL1341 JFK → MIA Jul 19, 20:47 UTCJul 19, 22:10 UTC1h 23m
2026-07-19 DAL1341 JFK → MIA Jul 19, 17:30 UTCJul 19, 19:00 UTC1h 30m
2026-07-19 DAL1479 MCO → LGA Jul 19, 14:40 UTCJul 19, 15:45 UTC1h 5m
2026-07-19 DAL1479 MCO → LGA Jul 19, 14:37 UTCJul 19, 15:40 UTC1h 3m
2026-07-19 DAL1479 MCO → LGA Jul 19, 11:45 UTCJul 19, 12:55 UTC1h 10m
2026-07-19 DAL2294 - Jul 19, 02:30 UTCJul 19, 04:00 UTC1h 30m
2026-07-18 DAL1539 ATL → TUL Jul 18, 21:35 UTCJul 18, 23:55 UTC2h 20m
2026-07-18 DAL1539 ATL → TUL Jul 18, 21:35 UTCJul 18, 23:53 UTC2h 18m
2026-07-18 DAL1539 ATL → TUL Jul 18, 16:40 UTCJul 18, 18:50 UTC2h 10m
2026-07-18 DAL1037 ATL → FAY Jul 18, 00:35 UTCJul 18, 03:15 UTC2h 41m
2026-07-17 DAL1037 ATL → FAY Jul 17, 20:35 UTCJul 17, 23:05 UTC2h 30m
2026-07-17 DAL655 - Jul 17, 15:35 UTCJul 17, 18:00 UTC2h 25m
2026-07-17 DAL655 - Jul 17, 11:30 UTCJul 17, 14:00 UTC2h 30m

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 N331DN page for operator, model, and routing details .

Mode-S A399DE frequently asked

What is Mode-S code A399DE?
A399DE is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N331DN.
Where is Mode-S A399DE registered?
Mode-S code A399DE 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 A399DE broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 20:05 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A399DE, octal 50714736, decimal 10,721,758.
What flights does A399DE operate?
Mode-S A399DE has broadcast 20 distinct callsigns, including DAL838, DAL598, DAL2886, DAL2593, DAL1527.