sensors Mode-S transponder

A4F239

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N418DX · AIRBUS A-330-900 · operated by DELTA AIR LINES INC

Hex
A4F239
Octal
51171071
Decimal
10,809,913
Country
US
Tail
N418DX
Type
A339
No current signal · last broadcast 2h ago
Flights observed
270
Distinct callsigns
20
Country
US
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S A4F239.

Country allocation

The ICAO 24-bit address A4F239 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
DAL145 - 15 2026-07-02
DAL56 - 14 2026-07-10
DAL80 - 13 2026-07-03
DAL21 - 13 2026-07-04
DAL81 Delta Air Lines 11 2026-07-03
DAL57 - 11 2026-06-27
DAL20 Delta Air Lines 11 2026-07-04
DAL142 Delta Air Lines 10 2026-07-05
DAL163 Delta Air Lines 9 2026-05-23
DAL221 - 8 2026-07-10
DAL227 - 7 2026-07-14
DAL165 - 7 2026-07-12
DAL164 - 7 2026-07-02
DAL220 Delta Air Lines 6 2026-06-27
DAL67 Delta Air Lines 5 2026-06-06
DAL243 - 5 2026-07-09
DAL226 - 5 2026-06-22
DAL225 - 5 2026-06-28
DAL224 - 5 2026-07-09
DAL223 Delta Air Lines 5 2026-06-05

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 DAL227 - Jul 14, 02:25 UTCJul 14, 02:55 UTC30m
2026-07-13 DAL4 - Jul 13, 16:25 UTCJul 13, 23:25 UTC7h 0m
2026-07-13 DAL4 LHR → JFK Jul 13, 16:22 UTCJul 13, 23:19 UTC6h 57m
2026-07-13 DAL10 MSP → LHR Jul 13, 04:17 UTCJul 13, 11:57 UTC7h 40m
2026-07-13 DAL10 - Jul 13, 04:20 UTCJul 13, 06:05 UTC1h 45m
2026-07-12 DAL165 - Jul 12, 12:55 UTCJul 12, 14:15 UTC1h 20m
2026-07-12 DAL165 AMS → MSP Jul 12, 12:54 UTCJul 12, 21:09 UTC8h 15m
2026-07-12 DAL136 - Jul 12, 02:45 UTCJul 12, 10:05 UTC7h 20m
2026-07-12 DAL136 DTW → AMS Jul 12, 02:42 UTCJul 12, 10:09 UTC7h 27m
2026-07-11 DAL137 - Jul 11, 13:00 UTCJul 11, 20:55 UTC7h 55m
2026-07-10 DAL56 SLC → AMS Jul 10, 22:55 UTCJul 11, 08:05 UTC9h 10m
2026-07-10 DAL221 - Jul 10, 09:30 UTCJul 10, 10:15 UTC45m
2026-07-10 DAL221 CDG → SLC Jul 10, 09:29 UTCJul 10, 19:31 UTC10h 2m
2026-07-09 DAL224 - Jul 9, 23:30 UTCJul 10, 05:50 UTC6h 20m
2026-07-09 DAL243 - Jul 9, 09:40 UTCJul 9, 10:15 UTC35m
2026-07-09 DAL243 AMS → BOS Jul 9, 09:40 UTCJul 9, 16:44 UTC7h 4m
2026-07-08 DAL132 - Jul 8, 20:40 UTCJul 8, 22:15 UTC1h 35m
2026-07-08 DAL132 DTW → AMS Jul 8, 20:35 UTCJul 9, 03:48 UTC7h 13m
2026-07-08 DAL23 - Jul 8, 07:15 UTCJul 8, 08:15 UTC1h 0m
2026-07-08 DAL23 MUC → DTW Jul 8, 07:15 UTCJul 8, 15:54 UTC8h 39m
2026-07-07 DAL22 DTW → MUC Jul 7, 20:45 UTCJul 8, 04:50 UTC8h 5m
2026-07-07 DAL207 - Jul 7, 07:20 UTCJul 7, 08:15 UTC55m
2026-07-07 DAL207 FCO → DTW Jul 7, 07:15 UTCJul 7, 16:22 UTC9h 7m
2026-07-06 DAL112 - Jul 6, 21:20 UTCJul 7, 04:40 UTC7h 20m
2026-07-06 DAL243 AMS → BOS Jul 6, 10:00 UTCJul 6, 17:15 UTC7h 15m
2026-07-05 DAL142 SEA → AMS Jul 5, 21:15 UTCJul 6, 06:10 UTC8h 55m
2026-07-04 DAL21 - Jul 4, 17:15 UTCJul 5, 03:10 UTC9h 55m
2026-07-04 DAL21 LHR → SEA Jul 4, 17:14 UTCJul 5, 03:09 UTC9h 55m
2026-07-04 DAL20 SEA → LHR Jul 4, 05:20 UTCJul 4, 14:15 UTC8h 55m
2026-07-04 DAL20 SEA → LHR Jul 4, 05:18 UTCJul 4, 14:12 UTC8h 54m
2026-07-03 DAL81 CDG → SEA Jul 3, 15:05 UTCJul 4, 01:00 UTC9h 55m
2026-07-03 DAL80 SEA → CDG Jul 3, 03:18 UTCJul 3, 12:20 UTC9h 2m
2026-07-03 DAL80 - Jul 3, 03:20 UTCJul 3, 05:45 UTC2h 25m
2026-07-02 DAL145 - Jul 2, 15:05 UTCJul 3, 00:25 UTC9h 20m
2026-07-02 DAL164 - Jul 2, 04:25 UTCJul 2, 11:25 UTC7h 0m
2026-07-01 DAL299 - Jul 1, 15:40 UTCJul 1, 20:05 UTC4h 25m
2026-07-01 DAL299 FCO → MSP Jul 1, 15:37 UTCJul 2, 01:48 UTC10h 11m
2026-07-01 DAL298 MSP → FCO Jul 1, 01:25 UTCJul 1, 10:25 UTC9h 0m
2026-06-30 DAL165 AMS → MSP Jun 30, 13:45 UTCJun 30, 22:10 UTC8h 25m
2026-06-30 DAL165 AMS → MSP Jun 30, 13:42 UTCJun 30, 22:05 UTC8h 23m
2026-06-29 DAL56 SLC → AMS Jun 29, 22:39 UTCJun 30, 07:35 UTC8h 56m
2026-06-29 DAL221 - Jun 29, 19:49 UTCJun 29, 20:09 UTC20m
2026-06-29 DAL221 - Jun 29, 09:34 UTCJun 29, 19:44 UTC10h 10m
2026-06-28 DAL224 - Jun 28, 23:34 UTCJun 29, 05:40 UTC6h 5m
2026-06-28 DAL225 - Jun 28, 10:24 UTCJun 28, 17:34 UTC7h 10m
2026-06-28 DAL225 CDG → BOS Jun 28, 10:24 UTCJun 28, 17:32 UTC7h 8m
2026-06-27 DAL220 SLC → CDG Jun 27, 22:15 UTCJun 28, 07:40 UTC9h 25m
2026-06-27 DAL220 SLC → CDG Jun 27, 22:13 UTCJun 28, 07:28 UTC9h 15m
2026-06-27 DAL57 AMS → SLC Jun 27, 09:35 UTCJun 27, 19:24 UTC9h 49m
2026-06-27 DAL57 - Jun 27, 09:40 UTCJun 27, 19:29 UTC9h 50m

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 N418DX page for operator, model, and routing details .

Mode-S A4F239 frequently asked

What is Mode-S code A4F239?
A4F239 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N418DX.
Where is Mode-S A4F239 registered?
Mode-S code A4F239 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 A4F239 broadcasting right now?
No active broadcast right now. Last signal was 2h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A4F239, octal 51171071, decimal 10,809,913.
What flights does A4F239 operate?
Mode-S A4F239 has broadcast 20 distinct callsigns, including DAL145, DAL56, DAL80, DAL21, DAL81.