Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A71AAD

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N557NW · BOEING 757-200 · operated by DELTA AIR LINES INC

Hex
A71AAD
Octal
51615255
Decimal
10,951,341
Country
US
Tail
N557NW
Type
B752
No current signal · last broadcast 1h ago
Flights observed
426
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S A71AAD.

Country allocation

The ICAO 24-bit address A71AAD 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
DAL391 - 15 2026-07-13
DAL1902 Delta Air Lines 12 2026-06-09
DAL955 - 7 2026-07-08
DAL755 Delta Air Lines 7 2026-05-04
DAL348 - 7 2026-06-19
DAL2076 Delta Air Lines 7 2026-05-22
DAL1336 - 7 2026-07-05
DAL1150 Delta Air Lines 7 2026-05-27
DAL929 - 6 2026-06-28
DAL689 - 6 2026-07-06
DAL502 Delta Air Lines 6 2026-06-09
DAL1089 - 6 2026-06-29
DAL1070 Delta Air Lines 6 2026-05-21
DAL824 Delta Air Lines 5 2026-06-03
DAL777 Delta Air Lines 5 2026-07-09
DAL748 Delta Air Lines 5 2026-06-26
DAL570 Delta Air Lines 5 2026-05-27
DAL423 Delta Air Lines 5 2026-05-04
DAL366 - 5 2026-06-27
DAL2286 - 5 2026-07-06

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 DAL1101 - Jul 14, 20:30 UTCJul 14, 21:15 UTC45m
2026-07-14 DAL1726 TPA → ATL Jul 14, 10:25 UTCJul 14, 11:30 UTC1h 5m
2026-07-14 DAL1560 ATL → TPA Jul 14, 03:30 UTCJul 14, 04:35 UTC1h 5m
2026-07-14 DAL1560 ATL → TPA Jul 14, 03:28 UTCJul 14, 04:27 UTC59m
2026-07-13 DAL591 LAS → ATL Jul 13, 22:10 UTCJul 14, 01:55 UTC3h 45m
2026-07-13 DAL421 - Jul 13, 16:25 UTCJul 13, 19:50 UTC3h 25m
2026-07-13 DAL1298 ATL → DTW Jul 13, 13:35 UTCJul 13, 15:00 UTC1h 25m
2026-07-13 DAL391 - Jul 13, 08:15 UTCJul 13, 11:45 UTC3h 30m
2026-07-13 DAL391 - Jul 13, 02:05 UTCJul 13, 06:05 UTC4h 0m
2026-07-12 - SJO → ATL Jul 12, 19:30 UTCJul 12, 23:00 UTC3h 30m
2026-07-12 DAL1937 ATL → SJO Jul 12, 14:15 UTCJul 12, 17:45 UTC3h 30m
2026-07-11 DAL1703 - Jul 11, 20:25 UTCJul 11, 23:15 UTC2h 50m
2026-07-11 DAL1703 GUA → ATL Jul 11, 20:22 UTCJul 11, 23:23 UTC3h 1m
2026-07-11 DAL1776 ATL → GUA Jul 11, 15:50 UTCJul 11, 18:40 UTC2h 50m
2026-07-11 DAL1776 ATL → GUA Jul 11, 15:47 UTCJul 11, 18:40 UTC2h 53m
2026-07-11 DAL1385 RSW → ATL Jul 11, 12:40 UTCJul 11, 13:55 UTC1h 15m
2026-07-11 DAL1217 ATL → RSW Jul 11, 03:30 UTCJul 11, 04:45 UTC1h 15m
2026-07-10 DAL591 LAS → ATL Jul 10, 22:25 UTCJul 11, 01:55 UTC3h 30m
2026-07-10 DAL421 DTW → LAS Jul 10, 16:35 UTCJul 10, 20:30 UTC3h 55m
2026-07-10 DAL1298 ATL → DTW Jul 10, 13:40 UTCJul 10, 15:05 UTC1h 25m
2026-07-10 DAL391 - Jul 10, 06:20 UTCJul 10, 10:10 UTC3h 50m
2026-07-10 DAL391 - Jul 10, 00:50 UTCJul 10, 04:55 UTC4h 5m
2026-07-09 DAL777 BOS → ORD Jul 9, 18:20 UTCJul 9, 22:05 UTC3h 45m
2026-07-09 DAL607 JFK → LAS Jul 9, 11:20 UTCJul 9, 16:20 UTC5h 0m
2026-07-09 DAL607 JFK → LAS Jul 9, 11:15 UTCJul 9, 16:16 UTC5h 1m
2026-07-08 DAL624 - Jul 8, 23:05 UTCJul 9, 03:40 UTC4h 35m
2026-07-08 DAL625 - Jul 8, 15:50 UTCJul 8, 19:15 UTC3h 25m
2026-07-08 DAL625 JFK → MEX Jul 8, 15:50 UTCJul 8, 20:38 UTC4h 48m
2026-07-08 DAL498 LAS → JFK Jul 8, 09:40 UTCJul 8, 14:10 UTC4h 30m
2026-07-08 DAL955 ATL → LAS Jul 8, 00:20 UTCJul 8, 04:00 UTC3h 40m
2026-07-07 DAL587 - Jul 7, 19:45 UTCJul 7, 22:35 UTC2h 50m
2026-07-07 DAL588 ATL → MEX Jul 7, 14:45 UTCJul 7, 17:40 UTC2h 55m
2026-07-07 DAL2080 MCO → ATL Jul 7, 11:20 UTCJul 7, 12:15 UTC55m
2026-07-07 DAL1162 ATL → MCO Jul 7, 03:05 UTCJul 7, 04:10 UTC1h 5m
2026-07-07 DAL1162 ATL → MCO Jul 7, 03:03 UTCJul 7, 04:03 UTC1h 0m
2026-07-06 DAL1785 - Jul 6, 20:30 UTCJul 6, 23:55 UTC3h 25m
2026-07-06 DAL2350 - Jul 6, 13:55 UTCJul 6, 17:15 UTC3h 20m
2026-07-06 DAL2286 - Jul 6, 10:25 UTCJul 6, 11:15 UTC50m
2026-07-06 DAL2286 JFK → ATL Jul 6, 10:25 UTCJul 6, 12:13 UTC1h 48m
2026-07-06 DAL689 - Jul 6, 06:40 UTCJul 6, 07:50 UTC1h 10m
2026-07-05 DAL689 - Jul 5, 23:10 UTCJul 6, 04:10 UTC5h 0m
2026-07-05 DAL549 ATL → LGA Jul 5, 17:20 UTCJul 5, 21:05 UTC3h 45m
2026-07-05 DAL1336 ORF → ATL Jul 5, 14:30 UTCJul 5, 15:45 UTC1h 15m
2026-07-05 DAL1336 ATL → ORF Jul 5, 11:45 UTCJul 5, 13:00 UTC1h 15m
2026-07-05 DAL391 - Jul 5, 06:10 UTCJul 5, 10:05 UTC3h 55m
2026-07-05 DAL391 - Jul 5, 00:00 UTCJul 5, 03:35 UTC3h 35m
2026-07-04 DAL777 BOS → ORD Jul 4, 17:50 UTCJul 4, 21:30 UTC3h 40m
2026-07-04 DAL777 BOS → ORD Jul 4, 12:45 UTCJul 4, 16:30 UTC3h 45m
2026-07-04 DAL391 - Jul 4, 06:20 UTCJul 4, 10:10 UTC3h 50m
2026-07-04 DAL391 - Jul 4, 00:20 UTCJul 4, 04:35 UTC4h 15m

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 N557NW page for operator, model, and routing details .

Mode-S A71AAD frequently asked

What is Mode-S code A71AAD?
A71AAD is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N557NW.
Where is Mode-S A71AAD registered?
Mode-S code A71AAD 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 A71AAD broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A71AAD, octal 51615255, decimal 10,951,341.
What flights does A71AAD operate?
Mode-S A71AAD has broadcast 20 distinct callsigns, including DAL391, DAL1902, DAL955, DAL755, DAL348.