Apparatus

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sensors Mode-S transponder

A0540A

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N120DN · AIRBUS A-321 · operated by DELTA AIR LINES INC

Hex
A0540A
Octal
50052012
Decimal
10,507,274
Country
US
Tail
N120DN
Type
A321
Broadcasting now · callsign DAL957 · 35,025 ft
Flights observed
570
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:30 UTC

Current position

A0540A is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A0540A 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
DAL1882 - 12 2026-06-22
DAL581 Delta Air Lines 11 2026-07-23
DAL2397 - 10 2026-07-20
DAL2591 Delta Air Lines 9 2026-04-23
DAL2589 - 9 2026-07-17
DAL1580 Delta Air Lines 9 2026-04-23
DAL582 Delta Air Lines 8 2026-07-23
DAL346 - 8 2026-07-05
DAL2603 Delta Air Lines 8 2026-07-25
DAL1730 Delta Air Lines 8 2026-04-23
DAL1461 - 7 2026-07-10
DAL994 - 6 2026-07-20
DAL992 - 6 2026-07-13
DAL2720 - 6 2026-06-19
DAL1078 Delta Air Lines 6 2026-07-25
DAL997 - 5 2026-06-29
DAL729 Delta Air Lines 5 2026-07-24
DAL519 Delta Air Lines 5 2026-06-24
DAL3024 - 5 2026-07-13
DAL2472 Delta Air Lines 5 2026-07-23

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 DAL2564 LGA → MCO Jul 26, 20:25 UTCJul 26, 22:30 UTC2h 5m
2026-07-26 DAL2564 LGA → MCO Jul 26, 16:05 UTCJul 26, 18:15 UTC2h 10m
2026-07-26 DAL2719 TLH → ATL Jul 26, 12:25 UTCJul 26, 14:35 UTC2h 10m
2026-07-25 DAL2191 JFK → SLC Jul 25, 22:35 UTCJul 26, 02:05 UTC3h 30m
2026-07-25 DAL2155 LGA → MCO Jul 25, 16:45 UTCJul 25, 20:50 UTC4h 5m
2026-07-25 DAL1078 BOS → LGA Jul 25, 13:52 UTCJul 25, 15:06 UTC1h 14m
2026-07-25 DAL1078 BOS → LGA Jul 25, 13:55 UTCJul 25, 15:10 UTC1h 15m
2026-07-25 DAL2603 DTW → LGA Jul 25, 02:15 UTCJul 25, 03:30 UTC1h 15m
2026-07-24 DAL2559 LGA → FLL Jul 24, 22:15 UTCJul 25, 00:45 UTC2h 30m
2026-07-24 DAL1379 JFK → LAX Jul 24, 19:35 UTCJul 24, 21:05 UTC1h 30m
2026-07-24 DAL729 SFO → LAX Jul 24, 13:40 UTCJul 24, 17:30 UTC3h 50m
2026-07-24 DAL896 MSP → PBI Jul 24, 01:50 UTCJul 24, 05:35 UTC3h 45m
2026-07-23 DAL581 AUA → ATL Jul 23, 20:35 UTCJul 23, 23:05 UTC2h 30m
2026-07-23 DAL581 AUA → ATL Jul 23, 19:30 UTCJul 23, 19:50 UTC20m
2026-07-23 DAL582 ATL → AUA Jul 23, 14:25 UTCJul 23, 18:00 UTC3h 35m
2026-07-23 DAL1200 BOS → SFO Jul 23, 10:15 UTCJul 23, 12:00 UTC1h 45m
2026-07-23 DAL2472 ATL → ALB Jul 23, 01:50 UTCJul 23, 03:35 UTC1h 45m
2026-07-23 DAL2472 ATL → ALB Jul 23, 01:49 UTCJul 23, 03:32 UTC1h 43m
2026-07-22 DAL581 AUA → ATL Jul 22, 20:30 UTCJul 22, 23:15 UTC2h 45m
2026-07-22 DAL581 AUA → ATL Jul 22, 19:35 UTCJul 22, 19:55 UTC20m
2026-07-22 DAL581 AUA → ATL Jul 22, 19:32 UTCJul 22, 23:12 UTC3h 40m
2026-07-22 DAL582 ATL → AUA Jul 22, 14:21 UTCJul 22, 17:53 UTC3h 32m
2026-07-22 DAL582 ATL → AUA Jul 22, 14:25 UTCJul 22, 17:55 UTC3h 30m
2026-07-22 DAL1069 - Jul 22, 11:15 UTCJul 22, 12:25 UTC1h 10m
2026-07-22 DAL1601 ATL → IAH Jul 22, 03:15 UTCJul 22, 04:40 UTC1h 25m
2026-07-21 DAL875 LGA → ATL Jul 21, 21:50 UTCJul 22, 01:05 UTC3h 15m
2026-07-21 DAL663 ATL → SLC Jul 21, 16:10 UTCJul 21, 19:30 UTC3h 20m
2026-07-21 DAL1530 - Jul 21, 13:05 UTCJul 21, 14:05 UTC1h 0m
2026-07-21 DAL2938 SJC → SLC Jul 21, 03:40 UTCJul 21, 04:50 UTC1h 10m
2026-07-21 DAL1206 - Jul 21, 00:00 UTCJul 21, 01:30 UTC1h 30m
2026-07-20 DAL1206 ATL → MKE Jul 20, 21:00 UTCJul 20, 22:35 UTC1h 35m
2026-07-20 DAL994 LGA → ATL Jul 20, 17:15 UTCJul 20, 19:00 UTC1h 45m
2026-07-20 DAL557 ATL → LGA Jul 20, 13:50 UTCJul 20, 15:40 UTC1h 50m
2026-07-20 DAL1200 BOS → SFO Jul 20, 10:35 UTCJul 20, 12:10 UTC1h 35m
2026-07-20 DAL2472 ATL → ROC Jul 20, 02:45 UTCJul 20, 04:25 UTC1h 40m
2026-07-20 DAL2472 ATL → ROC Jul 20, 02:45 UTCJul 20, 04:22 UTC1h 37m
2026-07-20 DAL2397 - Jul 20, 00:40 UTCJul 20, 01:15 UTC35m
2026-07-20 DAL2397 CAE → ATL Jul 20, 00:37 UTCJul 20, 01:12 UTC35m
2026-07-19 DAL2397 EWR → CAE Jul 19, 16:46 UTCJul 19, 19:09 UTC2h 23m
2026-07-19 DAL2397 - Jul 19, 16:50 UTCJul 19, 19:05 UTC2h 15m
2026-07-19 DAL2397 ATL → EWR Jul 19, 12:40 UTCJul 19, 14:20 UTC1h 40m
2026-07-19 DAL2722 SFO → ATL Jul 19, 09:50 UTCJul 19, 10:30 UTC40m
2026-07-19 DAL2722 SFO → ATL Jul 19, 09:46 UTCJul 19, 10:31 UTC45m
2026-07-18 DAL2315 - Jul 18, 23:45 UTCJul 19, 00:30 UTC45m
2026-07-18 DAL1101 MIA → ATL Jul 18, 20:10 UTCJul 18, 21:30 UTC1h 20m
2026-07-18 DAL1101 MIA → ATL Jul 18, 17:25 UTCJul 18, 18:40 UTC1h 15m
2026-07-18 DAL1334 - Jul 18, 14:30 UTCJul 18, 15:50 UTC1h 20m
2026-07-18 DAL1334 FLL → ATL Jul 18, 14:28 UTCJul 18, 15:50 UTC1h 22m
2026-07-18 DAL1334 ATL → FLL Jul 18, 11:15 UTCJul 18, 13:00 UTC1h 45m
2026-07-18 DAL2035 MCO → ATL Jul 18, 03:10 UTCJul 18, 04:10 UTC1h 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 N120DN page for operator, model, and routing details .

Mode-S A0540A frequently asked

What is Mode-S code A0540A?
A0540A is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N120DN.
Where is Mode-S A0540A registered?
Mode-S code A0540A 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 A0540A broadcasting right now?
Yes. Mode-S A0540A is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A0540A, octal 50052012, decimal 10,507,274.
What flights does A0540A operate?
Mode-S A0540A has broadcast 20 distinct callsigns, including DAL1882, DAL581, DAL2397, DAL2591, DAL2589.