Apparatus

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sensors Mode-S transponder

A6DFAA

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N542DE · AIRBUS A-321neo · operated by DELTA AIR LINES INC

Hex
A6DFAA
Octal
51557652
Decimal
10,936,234
Country
US
Tail
N542DE
Type
A21N
No current signal · last broadcast 5h ago
Flights observed
293
Distinct callsigns
20
Country
US
Last broadcast
5h ago

Last known position

Most recent position reported by Mode-S A6DFAA.

Country allocation

The ICAO 24-bit address A6DFAA 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
DAL1719 - 12 2026-07-13
DAL1780 Delta Air Lines 8 2026-06-03
DAL688 Delta Air Lines 6 2026-04-25
DAL613 - 6 2026-07-12
DAL821 Delta Air Lines 5 2026-05-28
DAL612 - 5 2026-07-12
DAL452 - 5 2026-07-05
DAL422 Delta Air Lines 5 2026-06-01
DAL332 Delta Air Lines 5 2026-05-25
DAL2436 Delta Air Lines 5 2026-06-21
DAL1966 - 5 2026-07-09
DAL1917 Delta Air Lines 5 2026-07-05
DAL465 - 4 2026-06-17
DAL443 Delta Air Lines 4 2026-06-01
DAL418 Delta Air Lines 4 2026-06-02
DAL1993 Delta Air Lines 4 2026-05-27
DAL1975 Delta Air Lines 4 2026-05-27
DAL1943 - 4 2026-07-13
DAL9887 - 3 2026-07-08
DAL885 Delta Air Lines 3 2026-05-28

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-13 DAL419 - Jul 13, 23:40 UTCJul 14, 00:25 UTC45m
2026-07-13 DAL1719 JFK → SEA Jul 13, 15:50 UTCJul 13, 21:05 UTC5h 15m
2026-07-13 DAL1719 JFK → SEA Jul 13, 15:47 UTCJul 13, 21:06 UTC5h 19m
2026-07-13 DAL1943 JFK → JFK Jul 13, 01:15 UTCJul 13, 13:30 UTC12h 15m
2026-07-12 DAL612 - Jul 12, 18:05 UTCJul 12, 22:00 UTC3h 55m
2026-07-12 DAL613 JFK → AUA Jul 12, 11:57 UTCJul 12, 16:18 UTC4h 21m
2026-07-12 DAL613 JFK → AUA Jul 12, 12:01 UTCJul 12, 16:20 UTC4h 20m
2026-07-11 DAL671 SLC → JFK Jul 11, 21:05 UTCJul 12, 01:15 UTC4h 10m
2026-07-11 DAL2031 - Jul 11, 15:00 UTCJul 11, 19:00 UTC4h 0m
2026-07-11 DAL2555 - Jul 11, 11:15 UTCJul 11, 13:20 UTC2h 5m
2026-07-11 DAL2255 SLC → DTW Jul 11, 00:45 UTCJul 11, 03:40 UTC2h 55m
2026-07-10 DAL526 ATL → SLC Jul 10, 19:50 UTCJul 10, 23:15 UTC3h 25m
2026-07-10 DAL897 - Jul 10, 14:25 UTCJul 10, 17:50 UTC3h 25m
2026-07-09 DAL863 JFK → SLC Jul 9, 22:40 UTCJul 10, 03:20 UTC4h 40m
2026-07-09 DAL1966 - Jul 9, 20:15 UTCJul 9, 21:05 UTC50m
2026-07-09 DAL1966 - Jul 9, 17:40 UTCJul 9, 17:55 UTC15m
2026-07-09 DAL1966 SJU → JFK Jul 9, 17:36 UTCJul 9, 21:03 UTC3h 27m
2026-07-09 DAL1966 - Jul 9, 15:50 UTCJul 9, 16:15 UTC25m
2026-07-09 DAL1966 - Jul 9, 12:25 UTCJul 9, 13:40 UTC1h 15m
2026-07-08 DAL9887 - Jul 8, 17:30 UTCJul 8, 20:55 UTC3h 25m
2026-07-08 DAL9887 - Jul 8, 16:45 UTCJul 8, 16:55 UTC10m
2026-07-08 DAL9887 AUA → JFK Jul 8, 16:40 UTCJul 8, 20:52 UTC4h 12m
2026-07-07 DAL613 JFK → AUA Jul 7, 11:50 UTCJul 7, 16:10 UTC4h 20m
2026-07-06 DAL336 DEN → JFK Jul 6, 14:15 UTCJul 6, 17:35 UTC3h 20m
2026-07-06 DAL424 JFK → ATL Jul 6, 01:49 UTCJul 6, 05:32 UTC3h 43m
2026-07-06 DAL424 JFK → ATL Jul 6, 01:50 UTCJul 6, 05:35 UTC3h 45m
2026-07-05 DAL1829 - Jul 5, 20:40 UTCJul 5, 21:30 UTC50m
2026-07-05 DAL1917 JFK → SDQ Jul 5, 12:59 UTCJul 5, 16:20 UTC3h 21m
2026-07-05 DAL1917 JFK → SDQ Jul 5, 13:00 UTCJul 5, 13:45 UTC45m
2026-07-05 DAL452 SEA → JFK Jul 5, 05:35 UTCJul 5, 10:00 UTC4h 25m
2026-07-04 DAL472 ATL → SEA Jul 4, 21:00 UTCJul 5, 01:55 UTC4h 55m
2026-06-24 DAL906 - Jun 24, 20:20 UTCJun 24, 23:24 UTC3h 5m
2026-06-24 DAL1698 LAS → SLC Jun 24, 18:09 UTCJun 24, 19:04 UTC55m
2026-06-24 DAL659 ATL → LAS Jun 24, 13:00 UTCJun 24, 16:50 UTC3h 50m
2026-06-23 DAL897 SJC → ATL Jun 23, 14:39 UTCJun 23, 18:04 UTC3h 25m
2026-06-22 DAL387 ATL → SLC Jun 22, 14:23 UTCJun 22, 18:12 UTC3h 49m
2026-06-22 DAL387 ATL → SLC Jun 22, 14:24 UTCJun 22, 18:15 UTC3h 50m
2026-06-21 DAL875 SLC → ATL Jun 21, 22:10 UTCJun 22, 01:15 UTC3h 5m
2026-06-21 DAL464 BOS → SLC Jun 21, 15:40 UTCJun 21, 20:29 UTC4h 50m
2026-06-21 DAL2436 SEA → CVG Jun 21, 11:15 UTCJun 21, 13:39 UTC2h 25m
2026-06-20 DAL718 - Jun 20, 23:29 UTCJun 21, 03:49 UTC4h 20m
2026-06-20 DAL1651 - Jun 20, 18:24 UTCJun 20, 22:00 UTC3h 35m
2026-06-20 DAL1651 MSP → LAX Jun 20, 18:24 UTCJun 20, 21:55 UTC3h 31m
2026-06-20 DAL792 - Jun 20, 13:44 UTCJun 20, 16:44 UTC3h 0m
2026-06-20 DAL1142 SLC → LAX Jun 20, 02:59 UTCJun 20, 04:31 UTC1h 32m
2026-06-20 DAL1142 - Jun 20, 02:59 UTCJun 20, 04:34 UTC1h 35m
2026-06-19 DAL2036 - Jun 19, 20:55 UTCJun 20, 01:24 UTC4h 30m
2026-06-19 DAL2036 MCO → SLC Jun 19, 20:53 UTCJun 20, 01:14 UTC4h 21m
2026-06-19 DAL482 - Jun 19, 14:39 UTCJun 19, 19:29 UTC4h 50m
2026-06-19 DAL476 ATL → SLC Jun 19, 00:10 UTCJun 19, 12:34 UTC12h 25m

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 N542DE page for operator, model, and routing details .

Mode-S A6DFAA frequently asked

What is Mode-S code A6DFAA?
A6DFAA is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N542DE.
Where is Mode-S A6DFAA registered?
Mode-S code A6DFAA 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 A6DFAA broadcasting right now?
No active broadcast right now. Last signal was 5h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A6DFAA, octal 51557652, decimal 10,936,234.
What flights does A6DFAA operate?
Mode-S A6DFAA has broadcast 20 distinct callsigns, including DAL1719, DAL1780, DAL688, DAL613, DAL821.