sensors Mode-S transponder

A491F1

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N394DA · BOEING 737-800 · operated by DELTA AIR LINES INC

Hex
A491F1
Octal
51110761
Decimal
10,785,265
Country
US
Tail
N394DA
Type
B738
Transponder active on ground
Flights observed
243
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S A491F1.

Country allocation

The ICAO 24-bit address A491F1 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

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 DAL587 MEX → ATL May 29, 19:45 UTCMay 29, 23:10 UTC3h 25m
2026-05-29 DAL588 ATL → MEX May 29, 15:20 UTCMay 29, 18:10 UTC2h 50m
2026-05-29 DAL3085 VPS → ATL May 29, 11:55 UTCMay 29, 12:45 UTC50m
2026-05-29 DAL882 SJC → SLC May 29, 00:25 UTCMay 29, 01:05 UTC40m
2026-05-28 DAL1750 MSP → MYR May 28, 21:10 UTCMay 28, 22:10 UTC1h 0m
2026-05-28 DAL1750 MSP → MYR May 28, 18:40 UTCMay 28, 19:45 UTC1h 5m
2026-05-28 DAL1841 KIN → ATL May 28, 15:05 UTCMay 28, 16:40 UTC1h 35m
2026-05-27 DAL1841 KIN → ATL May 27, 22:20 UTCMay 28, 16:40 UTC18h 20m
2026-05-27 DAL1906 ATL → KIN May 27, 22:10 UTCMay 27, 23:45 UTC1h 35m
2026-05-27 DAL1906 ATL → KIN May 27, 22:09 UTCMay 28, 00:42 UTC2h 33m
2026-05-27 DAL2179 SFO → SLC May 27, 19:15 UTCMay 27, 20:00 UTC45m
2026-05-27 DAL2179 SFO → SLC May 27, 17:05 UTCMay 27, 17:45 UTC40m
2026-05-27 DAL609 CUN → ATL May 27, 13:55 UTCMay 27, 15:15 UTC1h 20m
2026-05-27 DAL1939 ATL → CUN May 27, 00:30 UTCMay 27, 02:44 UTC2h 15m
2026-05-26 DAL2179 SFO → SLC May 26, 19:40 UTCMay 26, 20:24 UTC45m
2026-05-26 DAL2179 SFO → SLC May 26, 17:30 UTCMay 26, 18:14 UTC45m
2026-05-26 DAL1571 JFK → LAX May 26, 14:20 UTCMay 26, 15:35 UTC1h 15m
2026-05-26 DAL1571 JFK → LAX May 26, 11:54 UTCMay 26, 13:04 UTC1h 10m
2026-05-26 DAL2190 MSY → LGA May 26, 01:09 UTCMay 26, 03:12 UTC2h 3m
2026-05-26 DAL2190 MSY → LGA May 26, 01:10 UTCMay 26, 03:15 UTC2h 5m
2026-05-25 DAL1514 JFK → PBI May 25, 19:54 UTCMay 25, 22:25 UTC2h 30m
2026-05-25 DAL1514 JFK → PBI May 25, 15:15 UTCMay 25, 17:40 UTC2h 25m
2026-05-25 DAL1514 JFK → PBI May 25, 15:14 UTCMay 25, 17:39 UTC2h 25m
2026-05-25 DAL2475 LGA → RSW May 25, 11:35 UTCMay 25, 13:55 UTC2h 20m
2026-05-25 DAL2234 BDL → DTW May 25, 02:05 UTCMay 25, 03:00 UTC55m
2026-05-24 DAL1398 ATL → CVG May 24, 23:00 UTCMay 24, 23:05 UTC5m
2026-05-24 DAL1398 ATL → CVG May 24, 20:20 UTCMay 24, 21:50 UTC1h 30m
2026-05-24 DAL1398 ATL → CVG May 24, 16:55 UTCMay 24, 18:35 UTC1h 40m
2026-05-24 DAL1398 ATL → CVG May 24, 15:10 UTCMay 24, 16:50 UTC1h 40m
2026-05-23 DAL1224 LAX → SFO May 23, 22:30 UTCMay 23, 23:00 UTC30m
2026-05-23 DAL873 TPA → ATL May 23, 17:55 UTCMay 23, 21:05 UTC3h 10m
2026-05-23 DAL873 TPA → ATL May 23, 17:52 UTCMay 23, 21:01 UTC3h 9m
2026-05-23 DAL873 TPA → ATL May 23, 12:40 UTCMay 23, 16:25 UTC3h 45m
2026-05-23 DAL716 BOS → ATL May 23, 00:43 UTCMay 23, 03:54 UTC3h 11m
2026-05-23 DAL716 BOS → ATL May 23, 00:45 UTCMay 23, 04:05 UTC3h 19m
2026-05-22 DAL716 BOS → ATL May 22, 18:50 UTCMay 22, 22:35 UTC3h 45m
2026-05-22 DAL398 DFW → LGA May 22, 13:40 UTCMay 22, 17:05 UTC3h 25m
2026-05-21 DAL457 JFK → DEN May 21, 20:40 UTCMay 22, 01:15 UTC4h 35m
2026-05-21 DAL2623 IND → ATL May 21, 16:10 UTCMay 21, 18:35 UTC2h 25m
2026-05-21 DAL2623 IND → ATL May 21, 16:10 UTCMay 21, 18:34 UTC2h 24m
2026-05-21 DAL1245 BOS → MCO May 21, 12:00 UTCMay 21, 14:50 UTC2h 50m
2026-05-21 DAL2393 SFO → SEA May 21, 01:05 UTCMay 21, 02:40 UTC1h 35m
2026-05-20 DAL2782 MSY → ATL May 20, 22:30 UTCMay 20, 23:55 UTC1h 25m
2026-05-20 DAL760 ATL → BDL May 20, 17:20 UTCMay 20, 20:45 UTC3h 25m
2026-05-20 DAL760 ATL → BDL May 20, 17:19 UTCMay 20, 20:45 UTC3h 26m
2026-05-20 DAL760 ATL → BDL May 20, 12:10 UTCMay 20, 15:45 UTC3h 35m
2026-05-20 DAL2196 LGA → BOS May 20, 00:35 UTCMay 20, 03:30 UTC2h 55m
2026-05-19 DAL2196 LGA → BOS May 19, 20:35 UTCMay 19, 23:15 UTC2h 40m
2026-05-19 DAL1399 PHL → SLC May 19, 16:05 UTCMay 19, 18:15 UTC2h 10m
2026-05-19 DAL1399 PHL → SLC May 19, 16:04 UTCMay 19, 18:59 UTC2h 55m

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 N394DA page for operator, model, and routing details .

Mode-S A491F1 frequently asked

What is Mode-S code A491F1?
A491F1 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N394DA.
Where is Mode-S A491F1 registered?
Mode-S code A491F1 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 A491F1 broadcasting right now?
Mode-S A491F1 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 A491F1, octal 51110761, decimal 10,785,265.
What flights does A491F1 operate?
Mode-S A491F1 has broadcast 20 distinct callsigns, including DAL2905, DAL2419, DAL2267, DAL853, DAL306.