sensors Mode-S transponder

A4A0D9

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N398DN · AIRBUS A-321 · operated by BANK OF UTAH TRUSTEE

Hex
A4A0D9
Octal
51120331
Decimal
10,789,081
Country
US
Tail
N398DN
Type
A321
No current signal · last broadcast 6h ago
Flights observed
472
Distinct callsigns
20
Country
US
Last broadcast
6h ago

Last known position

Most recent position reported by Mode-S A4A0D9.

Country allocation

The ICAO 24-bit address A4A0D9 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
DAL1181 - 8 2026-07-04
DAL995 Delta Air Lines 7 2026-06-10
DAL999 - 6 2026-07-02
DAL974 - 6 2026-07-11
DAL839 Delta Air Lines 6 2026-04-29
DAL2465 - 6 2026-07-05
DAL2121 - 6 2026-06-29
DAL1659 - 6 2026-07-07
DAL402 Delta Air Lines 5 2026-05-06
DAL2602 - 5 2026-07-02
DAL1530 Delta Air Lines 5 2026-06-14
DAL1345 - 5 2026-04-13
DAL766 - 4 2026-07-12
DAL660 - 4 2026-07-12
DAL467 Delta Air Lines 4 2026-06-14
DAL2852 Delta Air Lines 4 2026-06-04
DAL2743 Delta Air Lines 4 2026-05-07
DAL2593 Delta Air Lines 4 2026-05-30
DAL2561 - 4 2026-07-10
DAL2460 Delta Air Lines 4 2026-05-02

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 DAL337 MCO → DTW Jul 14, 01:45 UTCJul 14, 04:10 UTC2h 25m
2026-07-13 DAL337 - Jul 13, 23:50 UTCJul 14, 00:25 UTC35m
2026-07-13 DAL337 - Jul 13, 18:45 UTCJul 13, 22:05 UTC3h 20m
2026-07-13 DAL864 LAS → DTW Jul 13, 13:10 UTCJul 13, 16:45 UTC3h 35m
2026-07-12 DAL766 - Jul 12, 20:45 UTCJul 12, 22:15 UTC1h 30m
2026-07-12 DAL766 DTW → LAS Jul 12, 20:45 UTCJul 13, 00:14 UTC3h 29m
2026-07-12 DAL2787 - Jul 12, 16:40 UTCJul 12, 19:05 UTC2h 25m
2026-07-12 DAL1317 SLC → DEN Jul 12, 14:06 UTCJul 12, 15:16 UTC1h 10m
2026-07-12 DAL1317 SLC → DEN Jul 12, 14:10 UTCJul 12, 15:15 UTC1h 5m
2026-07-12 DAL660 ATL → SLC Jul 12, 04:05 UTCJul 12, 07:31 UTC3h 25m
2026-07-12 DAL660 ATL → SLC Jul 12, 04:03 UTCJul 12, 07:25 UTC3h 22m
2026-07-11 DAL974 LGA → ATL Jul 11, 23:45 UTCJul 12, 01:30 UTC1h 45m
2026-07-11 DAL2719 MSP → LGA Jul 11, 14:15 UTCJul 11, 16:30 UTC2h 15m
2026-07-11 DAL2538 - Jul 11, 10:15 UTCJul 11, 12:35 UTC2h 20m
2026-07-11 DAL2938 ATL → RDU Jul 11, 03:50 UTCJul 11, 04:50 UTC1h 0m
2026-07-11 DAL2938 ATL → RDU Jul 11, 03:50 UTCJul 11, 04:50 UTC1h 0m
2026-07-10 DAL540 - Jul 10, 21:35 UTCJul 11, 01:30 UTC3h 55m
2026-07-10 DAL540 ATL → SAN Jul 10, 16:10 UTCJul 10, 20:05 UTC3h 55m
2026-07-10 DAL1505 MCO → ATL Jul 10, 13:20 UTCJul 10, 14:20 UTC1h 0m
2026-07-10 DAL1505 MCO → ATL Jul 10, 13:17 UTCJul 10, 14:16 UTC59m
2026-07-10 DAL2561 LGA → MCO Jul 10, 00:50 UTCJul 10, 03:17 UTC2h 27m
2026-07-10 DAL2561 LGA → MCO Jul 10, 00:55 UTCJul 10, 03:10 UTC2h 15m
2026-07-09 DAL1362 MCO → LGA Jul 9, 19:25 UTCJul 9, 21:45 UTC2h 20m
2026-07-09 DAL1362 MCO → LGA Jul 9, 19:24 UTCJul 9, 21:36 UTC2h 12m
2026-07-09 DAL2019 JFK → MCO Jul 9, 15:07 UTCJul 9, 17:17 UTC2h 10m
2026-07-09 DAL2019 JFK → MCO Jul 9, 15:10 UTCJul 9, 17:25 UTC2h 15m
2026-07-09 DAL2702 MCO → JFK Jul 9, 10:15 UTCJul 9, 12:15 UTC2h 0m
2026-07-09 DAL1735 - Jul 9, 04:20 UTCJul 9, 04:45 UTC25m
2026-07-09 DAL1735 ATL → TPA Jul 9, 01:00 UTCJul 9, 02:45 UTC1h 45m
2026-07-08 DAL1413 - Jul 8, 20:55 UTCJul 8, 22:20 UTC1h 25m
2026-07-08 DAL1413 ATL → FLL Jul 8, 18:00 UTCJul 8, 19:25 UTC1h 25m
2026-07-08 DAL1334 SAN → SEA Jul 8, 15:25 UTCJul 8, 16:45 UTC1h 20m
2026-07-08 DAL1334 SAN → SEA Jul 8, 12:30 UTCJul 8, 14:00 UTC1h 30m
2026-07-08 DAL912 SLC → ATL Jul 8, 05:55 UTCJul 8, 09:10 UTC3h 15m
2026-07-08 DAL833 - Jul 8, 02:25 UTCJul 8, 03:50 UTC1h 25m
2026-07-07 DAL1252 - Jul 7, 23:25 UTCJul 8, 00:55 UTC1h 30m
2026-07-07 DAL1659 LAS → SLC Jul 7, 20:30 UTCJul 7, 21:25 UTC55m
2026-07-07 DAL1659 LAS → SLC Jul 7, 20:29 UTCJul 7, 21:21 UTC52m
2026-07-07 DAL1659 SLC → LAS Jul 7, 17:55 UTCJul 7, 19:05 UTC1h 10m
2026-07-07 DAL2858 SLC → SJC Jul 7, 14:38 UTCJul 7, 16:03 UTC1h 25m
2026-07-07 DAL2858 SLC → SJC Jul 7, 14:40 UTCJul 7, 16:10 UTC1h 30m
2026-07-07 DAL2016 SLC → SEA Jul 7, 03:35 UTCJul 7, 05:05 UTC1h 30m
2026-07-06 DAL765 - Jul 6, 21:55 UTCJul 7, 01:05 UTC3h 10m
2026-07-06 DAL308 LGA → DTW Jul 6, 18:50 UTCJul 6, 20:15 UTC1h 25m
2026-07-06 DAL308 LGA → DTW Jul 6, 18:50 UTCJul 6, 20:11 UTC1h 21m
2026-07-06 DAL1164 - Jul 6, 15:05 UTCJul 6, 17:25 UTC2h 20m
2026-07-06 DAL1164 - Jul 6, 11:15 UTCJul 6, 13:30 UTC2h 15m
2026-07-06 DAL2520 - Jul 6, 00:35 UTCJul 6, 03:15 UTC2h 40m
2026-07-05 DAL2520 LGA → MCO Jul 5, 20:05 UTCJul 5, 22:30 UTC2h 25m
2026-07-05 DAL2465 - Jul 5, 15:45 UTCJul 5, 18:05 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 N398DN page for operator, model, and routing details .

Mode-S A4A0D9 frequently asked

What is Mode-S code A4A0D9?
A4A0D9 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N398DN.
Where is Mode-S A4A0D9 registered?
Mode-S code A4A0D9 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 A4A0D9 broadcasting right now?
No active broadcast right now. Last signal was 6h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A4A0D9, octal 51120331, decimal 10,789,081.
What flights does A4A0D9 operate?
Mode-S A4A0D9 has broadcast 20 distinct callsigns, including DAL1181, DAL995, DAL999, DAL974, DAL839.