sensors Mode-S transponder

ACF131

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N933DZ · operated by DELTA AIR LINES INC

Hex
ACF131
Octal
53170461
Decimal
11,333,937
Country
US
Tail
N933DZ
Type
B739
No current signal · last broadcast 1h ago
Flights observed
440
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S ACF131.

Country allocation

The ICAO 24-bit address ACF131 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
DAL728 - 8 2026-07-12
DAL2058 Delta Air Lines 8 2026-07-07
DAL637 - 7 2026-07-13
DAL481 - 5 2026-06-21
DAL3104 Delta Air Lines 5 2026-04-30
DAL3019 - 5 2026-07-10
DAL2999 Delta Air Lines 5 2026-05-20
DAL2738 - 5 2026-06-19
DAL2699 - 5 2026-06-28
DAL2651 - 5 2026-07-11
DAL1109 Delta Air Lines 5 2026-05-20
DAL904 - 4 2026-07-10
DAL682 - 4 2026-07-11
DAL3109 Delta Air Lines 4 2026-04-29
DAL2089 - 4 2026-07-06
DAL2022 Delta Air Lines 4 2026-06-15
DAL1663 Delta Air Lines 4 2026-06-04
DAL1437 Delta Air Lines 4 2026-05-21
DAL1244 - 4 2026-07-12
DAL1057 Delta Air Lines 4 2026-05-23

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-13 DAL637 ORD → SEA Jul 13, 23:20 UTCJul 14, 03:15 UTC3h 55m
2026-07-13 DAL637 SEA → ORD Jul 13, 18:00 UTCJul 13, 21:25 UTC3h 25m
2026-07-13 DAL354 - Jul 13, 10:50 UTCJul 13, 15:45 UTC4h 55m
2026-07-12 DAL489 SEA → RDU Jul 12, 23:10 UTCJul 13, 03:45 UTC4h 35m
2026-07-12 DAL728 DTW → SEA Jul 12, 16:50 UTCJul 12, 21:00 UTC4h 10m
2026-07-12 DAL728 DTW → SEA Jul 12, 16:50 UTCJul 12, 20:59 UTC4h 9m
2026-07-12 DAL2289 - Jul 12, 12:10 UTCJul 12, 15:10 UTC3h 0m
2026-07-12 DAL1244 - Jul 12, 00:20 UTCJul 12, 01:45 UTC1h 25m
2026-07-11 DAL1244 - Jul 11, 21:35 UTCJul 11, 23:05 UTC1h 30m
2026-07-11 DAL2651 MSP → SLC Jul 11, 17:50 UTCJul 11, 20:15 UTC2h 25m
2026-07-11 DAL2229 SMF → MSP Jul 11, 13:25 UTCJul 11, 16:20 UTC2h 55m
2026-07-11 DAL682 ATL → SMF Jul 11, 01:40 UTCJul 11, 06:05 UTC4h 25m
2026-07-11 DAL682 ATL → SMF Jul 11, 01:39 UTCJul 11, 06:09 UTC4h 30m
2026-07-10 DAL904 SMF → ATL Jul 10, 19:30 UTCJul 10, 23:30 UTC4h 0m
2026-07-10 DAL904 ATL → SMF Jul 10, 13:30 UTCJul 10, 17:45 UTC4h 15m
2026-07-10 DAL3019 PNS → ATL Jul 10, 11:05 UTCJul 10, 11:55 UTC50m
2026-07-10 DAL3021 ATL → PNS Jul 10, 00:40 UTCJul 10, 01:30 UTC50m
2026-07-09 DAL2427 COS → ATL Jul 9, 20:35 UTCJul 9, 23:00 UTC2h 25m
2026-07-09 DAL2427 COS → ATL Jul 9, 20:33 UTCJul 9, 22:58 UTC2h 25m
2026-07-09 DAL2427 ATL → COS Jul 9, 16:40 UTCJul 9, 19:05 UTC2h 25m
2026-07-09 DAL3100 - Jul 9, 14:40 UTCJul 9, 15:10 UTC30m
2026-07-09 DAL3100 - Jul 9, 12:45 UTCJul 9, 13:10 UTC25m
2026-07-08 DAL1150 MCO → ATL Jul 8, 22:25 UTCJul 8, 23:35 UTC1h 10m
2026-07-08 DAL1150 MCO → ATL Jul 8, 22:25 UTCJul 8, 23:34 UTC1h 9m
2026-07-08 DAL1150 ATL → MCO Jul 8, 19:50 UTCJul 8, 20:50 UTC1h 0m
2026-07-08 DAL1658 MCO → ATL Jul 8, 17:10 UTCJul 8, 18:10 UTC1h 0m
2026-07-08 DAL1658 MCO → ATL Jul 8, 17:08 UTCJul 8, 18:09 UTC1h 1m
2026-07-08 DAL1658 ATL → MCO Jul 8, 14:30 UTCJul 8, 15:35 UTC1h 5m
2026-07-07 DAL2058 GRR → ATL Jul 7, 22:30 UTCJul 8, 00:05 UTC1h 35m
2026-07-07 DAL2058 GRR → ATL Jul 7, 22:28 UTCJul 8, 00:02 UTC1h 34m
2026-07-07 DAL2058 GRR → ATL Jul 7, 19:35 UTCJul 7, 21:00 UTC1h 25m
2026-07-07 DAL741 SMF → ATL Jul 7, 13:50 UTCJul 7, 17:59 UTC4h 9m
2026-07-07 DAL741 SMF → ATL Jul 7, 13:50 UTCJul 7, 18:00 UTC4h 10m
2026-07-07 DAL682 ATL → SMF Jul 7, 01:30 UTCJul 7, 05:50 UTC4h 20m
2026-07-06 DAL1013 - Jul 6, 21:40 UTCJul 6, 22:25 UTC45m
2026-07-06 DAL1013 ATL → PNS Jul 6, 19:25 UTCJul 6, 20:15 UTC50m
2026-07-06 DAL570 ATL → BOS Jul 6, 13:25 UTCJul 6, 17:35 UTC4h 10m
2026-07-06 DAL2089 MSP → SFO Jul 6, 03:10 UTCJul 6, 06:35 UTC3h 25m
2026-07-06 DAL2089 MSP → SFO Jul 6, 03:09 UTCJul 6, 06:42 UTC3h 33m
2026-07-05 DAL703 - Jul 5, 23:50 UTCJul 6, 01:15 UTC1h 25m
2026-07-05 DAL703 MSP → CVG Jul 5, 21:05 UTCJul 5, 22:25 UTC1h 20m
2026-07-05 DAL1226 MSP → MSP Jul 5, 14:35 UTCJul 5, 19:35 UTC5h 0m
2026-07-05 DAL1274 - Jul 5, 11:10 UTCJul 5, 11:50 UTC40m
2026-07-05 DAL1599 - Jul 5, 02:40 UTCJul 5, 03:35 UTC55m
2026-07-04 DAL2843 - Jul 4, 22:05 UTCJul 4, 23:55 UTC1h 50m
2026-07-04 DAL2214 SLC → BNA Jul 4, 15:35 UTCJul 4, 18:30 UTC2h 55m
2026-07-04 DAL1440 GEG → SLC Jul 4, 12:15 UTCJul 4, 13:25 UTC1h 10m
2026-07-04 DAL1466 SLC → GEG Jul 4, 05:30 UTCJul 4, 07:00 UTC1h 30m
2026-07-04 DAL1244 - Jul 4, 01:05 UTCJul 4, 02:30 UTC1h 25m
2026-07-03 DAL1244 SLC → PDX Jul 3, 21:35 UTCJul 3, 23:05 UTC1h 30m

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 N933DZ page for operator, model, and routing details .

Mode-S ACF131 frequently asked

What is Mode-S code ACF131?
ACF131 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N933DZ.
Where is Mode-S ACF131 registered?
Mode-S code ACF131 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 ACF131 broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex ACF131, octal 53170461, decimal 11,333,937.
What flights does ACF131 operate?
Mode-S ACF131 has broadcast 20 distinct callsigns, including DAL728, DAL2058, DAL637, DAL481, DAL3104.