Apparatus

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sensors Mode-S transponder

A449AF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N3757D · BOEING 737-800 · operated by DELTA AIR LINES INC

Hex
A449AF
Octal
51044657
Decimal
10,766,767
Country
US
Tail
N3757D
Type
B738
Transponder active on ground
Flights observed
430
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S A449AF.

Country allocation

The ICAO 24-bit address A449AF 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
DAL593 - 10 2026-07-10
DAL589 - 10 2026-07-13
DAL585 - 8 2026-07-09
DAL2776 Delta Air Lines 8 2026-04-28
DAL3142 Delta Air Lines 7 2026-05-04
DAL2419 - 7 2026-07-03
DAL1166 Delta Air Lines 7 2026-05-23
DAL588 Delta Air Lines 6 2026-05-30
DAL587 Delta Air Lines 6 2026-05-30
DAL576 - 6 2026-07-11
DAL3014 Delta Air Lines 6 2026-05-26
DAL1359 Delta Air Lines 6 2026-05-31
DAL704 Delta Air Lines 5 2026-04-18
DAL661 - 5 2026-07-08
DAL590 - 5 2026-07-13
DAL577 - 5 2026-07-11
DAL3150 Delta Air Lines 5 2026-04-28
DAL2626 Delta Air Lines 5 2026-05-27
DAL2267 - 5 2026-06-29
DAL2194 Delta Air Lines 5 2026-07-05

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 DAL1650 - Jul 14, 12:35 UTCJul 14, 13:40 UTC1h 5m
2026-07-13 DAL2560 - Jul 13, 23:50 UTCJul 14, 02:15 UTC2h 25m
2026-07-13 DAL2912 - Jul 13, 20:40 UTCJul 13, 21:50 UTC1h 10m
2026-07-13 DAL3134 ATL → IND Jul 13, 18:10 UTCJul 13, 19:10 UTC1h 0m
2026-07-13 DAL590 - Jul 13, 13:25 UTCJul 13, 16:30 UTC3h 5m
2026-07-13 DAL589 - Jul 13, 04:15 UTCJul 13, 04:25 UTC10m
2026-07-13 DAL589 ATL → MEX Jul 13, 01:29 UTCJul 13, 03:59 UTC2h 30m
2026-07-13 DAL589 ATL → MEX Jul 13, 01:30 UTCJul 13, 04:25 UTC2h 55m
2026-07-12 DAL2200 - Jul 12, 21:50 UTCJul 12, 22:55 UTC1h 5m
2026-07-12 DAL2200 ATL → CMH Jul 12, 19:10 UTCJul 12, 20:30 UTC1h 20m
2026-07-11 DAL1906 ATL → ATL Jul 11, 22:40 UTCJul 12, 16:45 UTC18h 5m
2026-07-11 DAL576 - Jul 11, 17:50 UTCJul 11, 20:55 UTC3h 5m
2026-07-11 DAL577 ATL → MEX Jul 11, 12:45 UTCJul 11, 15:35 UTC2h 50m
2026-07-11 DAL2740 - Jul 11, 00:50 UTCJul 11, 02:20 UTC1h 30m
2026-07-10 DAL2738 ATL → ORD Jul 10, 21:05 UTCJul 10, 22:55 UTC1h 50m
2026-07-10 DAL593 - Jul 10, 15:00 UTCJul 10, 17:55 UTC2h 55m
2026-07-09 DAL585 - Jul 9, 22:40 UTCJul 10, 02:00 UTC3h 20m
2026-07-09 DAL1140 - Jul 9, 18:45 UTCJul 9, 19:50 UTC1h 5m
2026-07-09 DAL1140 CVG → ATL Jul 9, 18:44 UTCJul 9, 19:47 UTC1h 3m
2026-07-09 DAL511 MCO → CVG Jul 9, 15:40 UTCJul 9, 17:30 UTC1h 50m
2026-07-09 DAL511 - Jul 9, 12:40 UTCJul 9, 14:20 UTC1h 40m
2026-07-08 DAL661 - Jul 8, 23:25 UTCJul 9, 01:25 UTC2h 0m
2026-07-08 DAL661 - Jul 8, 19:45 UTCJul 8, 21:55 UTC2h 10m
2026-07-08 DAL2774 IAH → DTW Jul 8, 16:30 UTCJul 8, 18:25 UTC1h 55m
2026-07-08 DAL1401 BOS → FLL Jul 8, 12:05 UTCJul 8, 14:55 UTC2h 50m
2026-07-08 DAL522 - Jul 8, 01:30 UTCJul 8, 04:15 UTC2h 45m
2026-07-08 DAL522 FLL → BOS Jul 8, 01:27 UTCJul 8, 04:11 UTC2h 44m
2026-07-07 DAL2321 LGA → FLL Jul 7, 21:41 UTCJul 8, 00:02 UTC2h 21m
2026-07-07 DAL2321 LGA → FLL Jul 7, 21:45 UTCJul 8, 00:10 UTC2h 25m
2026-07-07 DAL873 - Jul 7, 15:55 UTCJul 7, 19:00 UTC3h 5m
2026-07-07 DAL873 DFW → LGA Jul 7, 15:52 UTCJul 7, 19:01 UTC3h 9m
2026-07-07 DAL873 LGA → DFW Jul 7, 11:10 UTCJul 7, 14:20 UTC3h 10m
2026-07-07 DAL2466 BOS → ROC Jul 7, 02:25 UTCJul 7, 04:35 UTC2h 10m
2026-07-06 DAL2460 LGA → PBI Jul 6, 22:25 UTCJul 7, 01:01 UTC2h 36m
2026-07-06 DAL2460 LGA → PBI Jul 6, 22:25 UTCJul 7, 01:00 UTC2h 35m
2026-07-06 DAL716A - Jul 6, 19:15 UTCJul 6, 20:10 UTC55m
2026-07-05 DAL716 BOS → ATL Jul 5, 23:45 UTCJul 6, 02:45 UTC3h 0m
2026-07-05 DAL716 BOS → ATL Jul 5, 18:25 UTCJul 5, 22:00 UTC3h 35m
2026-07-05 DAL2194 BDL → ATL Jul 5, 15:20 UTCJul 5, 15:45 UTC25m
2026-07-05 DAL2194 BDL → ATL Jul 5, 15:10 UTCJul 5, 16:25 UTC1h 15m
2026-07-05 DAL2194 BDL → ATL Jul 5, 12:25 UTCJul 5, 13:40 UTC1h 15m
2026-07-05 DAL2336 ATL → TLH Jul 5, 04:35 UTCJul 5, 06:10 UTC1h 35m
2026-07-04 DAL2055 SEA → ORD Jul 4, 14:45 UTCJul 4, 18:30 UTC3h 45m
2026-07-04 DAL2956 LAS → SEA Jul 4, 02:55 UTCJul 4, 05:05 UTC2h 10m
2026-07-04 DAL2956 LAS → SEA Jul 4, 02:55 UTCJul 4, 05:06 UTC2h 11m
2026-07-03 DAL2955 SEA → LAS Jul 3, 23:55 UTCJul 4, 01:45 UTC1h 50m
2026-07-03 DAL2419 - Jul 3, 19:20 UTCJul 3, 22:00 UTC2h 40m
2026-07-03 DAL2419 SEA → PHX Jul 3, 15:35 UTCJul 3, 17:55 UTC2h 20m
2026-07-02 DAL2419 - Jul 2, 19:20 UTCJul 2, 22:05 UTC2h 45m
2026-07-02 DAL2419 PHX → SEA Jul 2, 19:17 UTCJul 2, 22:00 UTC2h 43m

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 N3757D page for operator, model, and routing details .

Mode-S A449AF frequently asked

What is Mode-S code A449AF?
A449AF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N3757D.
Where is Mode-S A449AF registered?
Mode-S code A449AF 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 A449AF broadcasting right now?
Mode-S A449AF is currently broadcasting from the ground.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A449AF, octal 51044657, decimal 10,766,767.
What flights does A449AF operate?
Mode-S A449AF has broadcast 20 distinct callsigns, including DAL593, DAL589, DAL585, DAL2776, DAL3142.