Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A4CE71

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N409DX · AIRBUS A-330-900 · operated by BANK OF UTAH TRUSTEE

Hex
A4CE71
Octal
51147161
Decimal
10,800,753
Country
US
Tail
N409DX
Type
A339
No current signal · last broadcast Jul 26, 18:50 UTC
Flights observed
223
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 18:50 UTC

Last known position

Most recent position reported by Mode-S A4CE71.

Country allocation

The ICAO 24-bit address A4CE71 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
DAL81 Delta Air Lines 8 2026-05-23
DAL63 Delta Air Lines 8 2026-07-24
DAL59 Delta Air Lines 8 2026-06-08
DAL108 Delta Air Lines 8 2026-07-24
DAL243 - 7 2026-06-18
DAL240 Delta Air Lines 7 2026-06-18
DAL16 Delta Air Lines 7 2026-06-07
DAL70 Delta Air Lines 6 2026-06-06
DAL57 Delta Air Lines 6 2026-06-09
DAL20 Delta Air Lines 6 2026-05-24
DAL133 Delta Air Lines 6 2026-06-07
DAL742 - 5 2026-04-13
DAL71 Delta Air Lines 5 2026-06-06
DAL62 Delta Air Lines 5 2026-07-19
DAL242 - 5 2026-07-15
DAL225 Delta Air Lines 5 2026-06-10
DAL224 Delta Air Lines 5 2026-07-24
DAL220 Delta Air Lines 5 2026-06-09
DAL145 Delta Air Lines 5 2026-05-22
DAL109 Delta Air Lines 5 2026-07-20

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 DAL237 KEF → DTW Jul 26, 16:50 UTCJul 26, 18:50 UTC2h 0m
2026-07-26 DAL56 SLC → AMS Jul 26, 05:35 UTCJul 26, 14:15 UTC8h 41m
2026-07-26 DAL56 SLC → AMS Jul 26, 05:32 UTCJul 26, 14:21 UTC8h 49m
2026-07-25 DAL221 CDG → SLC Jul 25, 09:45 UTCJul 25, 20:00 UTC10h 15m
2026-07-24 DAL224 SEA → AMS Jul 24, 23:20 UTCJul 25, 05:40 UTC6h 20m
2026-07-24 DAL63 FCO → ATL Jul 24, 13:10 UTCJul 24, 19:55 UTC6h 45m
2026-07-24 DAL108 ATL → MAD Jul 24, 02:37 UTCJul 24, 10:41 UTC8h 4m
2026-07-24 DAL108 ATL → MAD Jul 24, 02:40 UTCJul 24, 10:55 UTC8h 15m
2026-07-23 DAL297 SPN → NRT Jul 23, 10:00 UTCJul 23, 21:15 UTC11h 15m
2026-07-22 DAL296 HND → ATL Jul 22, 20:30 UTCJul 23, 06:40 UTC10h 10m
2026-07-21 DAL55 - Jul 21, 07:30 UTCJul 22, 00:30 UTC17h 0m
2026-07-21 DAL55 - Jul 21, 00:20 UTCJul 22, 00:15 UTC23h 55m
2026-07-20 DAL54 ATL → LOS Jul 20, 23:30 UTCJul 21, 16:45 UTC17h 14m
2026-07-20 DAL109 MAD → ATL Jul 20, 08:15 UTCJul 20, 16:50 UTC8h 35m
2026-07-19 DAL62 ATL → FCO Jul 19, 22:10 UTCJul 20, 04:31 UTC6h 21m
2026-07-19 DAL62 ATL → FCO Jul 19, 22:10 UTCJul 20, 04:15 UTC6h 5m
2026-07-18 DAL257 AMS → BOS Jul 18, 13:08 UTCJul 18, 20:02 UTC6h 54m
2026-07-18 DAL257 - Jul 18, 13:10 UTCJul 18, 14:15 UTC1h 5m
2026-07-18 DAL144 SEA → AMS Jul 18, 01:00 UTCJul 18, 09:45 UTC8h 46m
2026-07-17 DAL249 BCN → SEA Jul 17, 12:00 UTCJul 17, 22:51 UTC10h 51m
2026-07-17 DAL249 - Jul 17, 12:04 UTCJul 17, 14:15 UTC2h 10m
2026-07-16 DAL248 SEA → BCN Jul 16, 23:07 UTCJul 17, 09:15 UTC10h 8m
2026-07-16 DAL248 SEA → BCN Jul 16, 23:10 UTCJul 17, 09:20 UTC10h 10m
2026-07-16 DAL143 - Jul 16, 08:45 UTCJul 16, 18:15 UTC9h 30m
2026-07-15 DAL242 BOS → AMS Jul 15, 23:15 UTCJul 16, 05:34 UTC6h 19m
2026-07-15 DAL242 - Jul 15, 23:15 UTCJul 16, 00:15 UTC1h 0m
2026-07-15 DAL63 - Jul 15, 13:00 UTCJul 15, 20:15 UTC7h 15m
2026-07-15 DAL63 MAD → BOS Jul 15, 12:57 UTCJul 15, 20:13 UTC7h 16m
2026-07-15 DAL108 ATL → MAD Jul 15, 02:10 UTCJul 15, 10:10 UTC8h 0m
2026-07-14 DAL1425 TPA → ATL Jul 14, 00:00 UTCJul 14, 01:05 UTC1h 5m
2026-07-13 DAL1425 ATL → TPA Jul 13, 21:05 UTCJul 13, 22:20 UTC1h 15m
2026-06-19 DAL223 ATH → ATL Jun 19, 07:09 UTCJun 19, 18:49 UTC11h 40m
2026-06-18 DAL240 BOS → ATH Jun 18, 19:45 UTCJun 19, 04:28 UTC8h 43m
2026-06-18 DAL240 BOS → ATH Jun 18, 19:45 UTCJun 19, 04:14 UTC8h 29m
2026-06-18 DAL243 - Jun 18, 09:40 UTCJun 18, 10:15 UTC35m
2026-06-18 DAL243 AMS → BOS Jun 18, 09:41 UTCJun 18, 16:39 UTC6h 58m
2026-06-18 DAL243 AMS → BOS Jun 18, 09:41 UTCJun 18, 16:49 UTC7h 8m
2026-06-17 DAL242 BOS → AMS Jun 17, 23:25 UTCJun 18, 05:40 UTC6h 15m
2026-06-17 DAL63 FCO → ATL Jun 17, 13:15 UTCJun 17, 20:20 UTC7h 5m
2026-06-17 DAL108 - Jun 17, 02:00 UTCJun 17, 09:40 UTC7h 40m
2026-06-16 DAL215 - Jun 16, 08:25 UTCJun 16, 18:50 UTC10h 25m
2026-06-15 DAL214 ATL → FCO Jun 15, 20:10 UTCJun 16, 04:50 UTC8h 40m
2026-06-14 DAL759 - Jun 14, 22:45 UTCJun 14, 23:50 UTC1h 4m
2026-06-14 DAL759 ATL → TPA Jun 14, 20:20 UTCJun 14, 21:30 UTC1h 10m
2026-06-14 DAL109 - Jun 14, 17:15 UTCJun 14, 17:30 UTC15m
2026-06-14 DAL109 - Jun 14, 08:15 UTCJun 14, 09:20 UTC1h 5m
2026-06-14 DAL109 MAD → ATL Jun 14, 08:13 UTCJun 14, 17:00 UTC8h 47m
2026-06-13 DAL62 ATL → FCO Jun 13, 23:05 UTCJun 14, 04:15 UTC5h 10m
2026-06-13 DAL62 ATL → FCO Jun 13, 23:03 UTCJun 14, 05:15 UTC6h 12m
2026-06-13 DAL125 LIS → BOS Jun 13, 12:10 UTCJun 13, 18:45 UTC6h 35m

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 N409DX page for operator, model, and routing details .

Mode-S A4CE71 frequently asked

What is Mode-S code A4CE71?
A4CE71 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N409DX.
Where is Mode-S A4CE71 registered?
Mode-S code A4CE71 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 A4CE71 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 18:50 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A4CE71, octal 51147161, decimal 10,800,753.
What flights does A4CE71 operate?
Mode-S A4CE71 has broadcast 20 distinct callsigns, including DAL81, DAL63, DAL59, DAL108, DAL243.