Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A4B0BB

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N401DZ · AIRBUS A-330-900 · operated by DELTA AIR LINES INC

Hex
A4B0BB
Octal
51130273
Decimal
10,793,147
Country
US
Tail
N401DZ
Type
A339
No current signal · last broadcast 2h ago
Flights observed
272
Distinct callsigns
20
Country
US
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S A4B0BB.

Country allocation

The ICAO 24-bit address A4B0BB 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
DAL257 - 10 2026-06-18
DAL296 - 9 2026-07-12
DAL221 - 9 2026-06-16
DAL162 Delta Air Lines 9 2026-05-09
DAL58 - 8 2026-06-18
DAL56 - 8 2026-06-16
DAL137 Delta Air Lines 8 2026-06-26
DAL4 - 7 2026-07-01
DAL297 - 7 2026-07-13
DAL223 - 7 2026-07-12
DAL17 Delta Air Lines 7 2026-06-19
DAL165 Delta Air Lines 7 2026-06-27
DAL16 Delta Air Lines 7 2026-06-03
DAL136 - 7 2026-06-27
DAL124 Delta Air Lines 7 2026-05-10
DAL10 - 7 2026-07-01
DAL972 - 6 2026-07-04
DAL48 - 6 2026-06-26
DAL241 Delta Air Lines 6 2026-05-18
DAL224 - 6 2026-06-15

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 DAL222 - Jul 14, 01:35 UTCJul 14, 04:30 UTC2h 55m
2026-07-13 DAL297 ATH → ATL Jul 13, 10:27 UTCJul 13, 21:58 UTC11h 31m
2026-07-13 DAL297 ATH → ATL Jul 13, 10:30 UTCJul 13, 22:00 UTC11h 30m
2026-07-12 DAL296 - Jul 12, 23:05 UTCJul 13, 07:55 UTC8h 50m
2026-07-12 DAL296 - Jul 12, 21:30 UTCJul 12, 23:00 UTC1h 30m
2026-07-12 DAL296 ATL → ATH Jul 12, 21:29 UTCJul 13, 07:49 UTC10h 20m
2026-07-12 DAL223 ATH → ATL Jul 12, 07:05 UTCJul 12, 18:25 UTC11h 20m
2026-07-11 DAL202 JFK → ATH Jul 11, 19:30 UTCJul 12, 04:25 UTC8h 55m
2026-07-10 DAL213 ATH → JFK Jul 10, 15:35 UTCJul 11, 01:36 UTC10h 1m
2026-07-10 DAL213 ATH → JFK Jul 10, 15:35 UTCJul 11, 01:46 UTC10h 11m
2026-07-10 DAL213 - Jul 10, 15:40 UTCJul 10, 18:45 UTC3h 5m
2026-07-10 DAL212 JFK → ATH Jul 10, 04:20 UTCJul 10, 13:15 UTC8h 55m
2026-07-09 DAL203 ATH → JFK Jul 9, 07:20 UTCJul 9, 17:25 UTC10h 5m
2026-07-08 DAL202 JFK → ATH Jul 8, 19:25 UTCJul 9, 04:25 UTC9h 0m
2026-07-08 DAL1034 ATL → JFK Jul 8, 14:42 UTCJul 8, 16:26 UTC1h 44m
2026-07-08 DAL1034 ATL → JFK Jul 8, 14:45 UTCJul 8, 16:25 UTC1h 40m
2026-07-08 DAL104 - Jul 8, 02:15 UTCJul 8, 11:25 UTC9h 10m
2026-07-06 DAL105 - Jul 6, 23:15 UTCJul 7, 08:15 UTC9h 0m
2026-07-06 DAL195 BCN → ATL Jul 6, 09:50 UTCJul 6, 19:15 UTC9h 25m
2026-07-05 DAL128 BCN → JFK Jul 5, 23:41 UTCJul 6, 06:37 UTC6h 56m
2026-07-05 DAL128 BCN → JFK Jul 5, 23:45 UTCJul 6, 01:15 UTC1h 30m
2026-07-05 DAL939 YQG → JFK Jul 5, 16:15 UTCJul 5, 17:40 UTC1h 25m
2026-07-04 DAL939 LAX → DTW Jul 4, 19:45 UTCJul 5, 00:55 UTC5h 10m
2026-07-04 DAL713 JFK → LAX Jul 4, 12:30 UTCJul 4, 18:05 UTC5h 35m
2026-07-04 DAL972 - Jul 4, 02:40 UTCJul 4, 03:15 UTC35m
2026-07-04 DAL972 PHL → PHL Jul 4, 02:25 UTCJul 4, 02:30 UTC5m
2026-07-03 DAL972 LAX → PHL Jul 3, 18:55 UTCJul 4, 00:50 UTC5h 55m
2026-07-03 DAL742 JFK → LAX Jul 3, 11:45 UTCJul 3, 16:54 UTC5h 9m
2026-07-03 DAL742 JFK → LAX Jul 3, 11:45 UTCJul 3, 17:00 UTC5h 15m
2026-07-03 DAL226 - Jul 3, 00:00 UTCJul 3, 09:10 UTC9h 10m
2026-07-02 DAL227 - Jul 2, 02:50 UTCJul 2, 11:50 UTC9h 0m
2026-07-01 DAL4 - Jul 1, 16:05 UTCJul 1, 23:25 UTC7h 20m
2026-07-01 DAL10 MSP → LHR Jul 1, 04:15 UTCJul 1, 11:20 UTC7h 5m
2026-06-30 DAL9 - Jun 30, 11:55 UTCJun 30, 20:00 UTC8h 5m
2026-06-30 DAL3 JFK → LHR Jun 30, 02:55 UTCJun 30, 09:15 UTC6h 20m
2026-06-29 DAL972 LAX → JFK Jun 29, 18:44 UTCJun 29, 23:25 UTC4h 40m
2026-06-29 DAL742 - Jun 29, 11:29 UTCJun 29, 16:44 UTC5h 15m
2026-06-28 DAL4 - Jun 28, 22:59 UTCJun 29, 00:29 UTC1h 30m
2026-06-28 DAL4 - Jun 28, 17:30 UTCJun 28, 22:55 UTC5h 25m
2026-06-28 DAL4 LHR → JFK Jun 28, 17:25 UTCJun 29, 00:20 UTC6h 55m
2026-06-28 DAL10 MSP → LHR Jun 28, 04:32 UTCJun 28, 11:51 UTC7h 19m
2026-06-28 DAL10 MSP → LHR Jun 28, 04:35 UTCJun 28, 11:59 UTC7h 25m
2026-06-27 DAL165 AMS → MSP Jun 27, 14:12 UTCJun 27, 22:28 UTC8h 16m
2026-06-27 DAL165 AMS → MSP Jun 27, 14:14 UTCJun 27, 22:29 UTC8h 15m
2026-06-27 DAL136 - Jun 27, 02:39 UTCJun 27, 09:55 UTC7h 15m
2026-06-26 DAL137 AMS → DTW Jun 26, 12:50 UTCJun 26, 20:40 UTC7h 50m
2026-06-26 DAL48 - Jun 26, 03:05 UTCJun 26, 09:30 UTC6h 25m
2026-06-26 DAL48 JFK → AMS Jun 26, 03:04 UTCJun 26, 09:26 UTC6h 22m
2026-06-25 DAL972 LAX → JFK Jun 25, 18:59 UTCJun 25, 23:24 UTC4h 25m
2026-06-25 DAL972 LAX → JFK Jun 25, 18:58 UTCJun 25, 23:19 UTC4h 21m

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 N401DZ page for operator, model, and routing details .

Mode-S A4B0BB frequently asked

What is Mode-S code A4B0BB?
A4B0BB is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N401DZ.
Where is Mode-S A4B0BB registered?
Mode-S code A4B0BB 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 A4B0BB 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 A4B0BB, octal 51130273, decimal 10,793,147.
What flights does A4B0BB operate?
Mode-S A4B0BB has broadcast 20 distinct callsigns, including DAL257, DAL296, DAL221, DAL162, DAL58.