Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A539C9

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N436DX · AIRBUS A-330-900 · operated by BANK OF UTAH TRUSTEE

Hex
A539C9
Octal
51234711
Decimal
10,828,233
Country
US
Tail
N436DX
Type
A339
No current signal · last broadcast 1h ago
Flights observed
290
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S A539C9.

Country allocation

The ICAO 24-bit address A539C9 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
DAL133 - 11 2026-06-25
DAL132 - 10 2026-07-13
DAL273 - 9 2026-07-04
DAL58 - 8 2026-07-12
DAL272 - 8 2026-07-04
DAL17 - 8 2026-07-13
DAL240 Delta Air Lines 7 2026-06-16
DAL157 - 7 2026-07-02
DAL70 Delta Air Lines 6 2026-05-18
DAL223 - 6 2026-06-17
DAL215 Delta Air Lines 6 2026-06-10
DAL71 Delta Air Lines 5 2026-05-18
DAL67 Delta Air Lines 5 2026-05-14
DAL55 - 5 2026-06-18
DAL54 - 5 2026-06-17
DAL213 Delta Air Lines 5 2026-07-05
DAL207 Delta Air Lines 5 2026-04-16
DAL16 - 5 2026-06-23
DAL156 - 5 2026-07-01
DAL108 - 5 2026-06-15

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-13 DAL132 - Jul 13, 20:40 UTCJul 14, 04:15 UTC7h 35m
2026-07-13 DAL17 - Jul 13, 10:05 UTCJul 13, 11:25 UTC1h 20m
2026-07-13 DAL17 LHR → DTW Jul 13, 10:02 UTCJul 13, 17:39 UTC7h 37m
2026-07-12 DAL58 BOS → LHR Jul 12, 23:23 UTCJul 13, 05:35 UTC6h 12m
2026-07-12 DAL58 - Jul 12, 23:25 UTCJul 13, 05:40 UTC6h 15m
2026-07-12 DAL257 AMS → BOS Jul 12, 13:04 UTCJul 12, 19:52 UTC6h 48m
2026-07-12 DAL257 - Jul 12, 13:05 UTCJul 12, 14:45 UTC1h 40m
2026-07-12 DAL144 SEA → AMS Jul 12, 01:12 UTCJul 12, 10:13 UTC9h 1m
2026-07-12 DAL144 - Jul 12, 01:15 UTCJul 12, 01:55 UTC40m
2026-07-11 DAL43 FCO → SEA Jul 11, 10:40 UTCJul 11, 22:15 UTC11h 35m
2026-07-10 DAL42 SEA → FCO Jul 10, 21:30 UTCJul 11, 08:06 UTC10h 36m
2026-07-10 DAL42 - Jul 10, 21:30 UTCJul 10, 22:15 UTC45m
2026-07-09 DAL21 - Jul 9, 17:20 UTCJul 9, 18:15 UTC55m
2026-07-09 DAL21 LHR → SEA Jul 9, 17:19 UTCJul 10, 02:40 UTC9h 21m
2026-07-09 DAL20 - Jul 9, 05:25 UTCJul 9, 08:05 UTC2h 40m
2026-07-09 DAL20 SEA → LHR Jul 9, 05:25 UTCJul 9, 14:39 UTC9h 14m
2026-07-08 DAL81 - Jul 8, 14:40 UTCJul 9, 00:15 UTC9h 35m
2026-07-08 DAL81 CDG → SEA Jul 8, 14:39 UTCJul 9, 00:11 UTC9h 32m
2026-07-08 DAL80 SEA → CDG Jul 8, 02:45 UTCJul 8, 12:04 UTC9h 19m
2026-07-07 DAL145 - Jul 7, 14:10 UTCJul 8, 00:00 UTC9h 50m
2026-07-07 DAL164 MSP → AMS Jul 7, 03:37 UTCJul 7, 11:21 UTC7h 44m
2026-07-07 DAL164 MSP → AMS Jul 7, 03:40 UTCJul 7, 11:20 UTC7h 40m
2026-07-06 DAL9 - Jul 6, 13:55 UTCJul 6, 22:05 UTC8h 10m
2026-07-06 DAL9 LHR → MSP Jul 6, 13:54 UTCJul 6, 22:02 UTC8h 8m
2026-07-06 DAL3 JFK → LHR Jul 6, 05:20 UTCJul 6, 11:40 UTC6h 20m
2026-07-05 DAL213 ATH → JFK Jul 5, 12:49 UTCJul 5, 23:13 UTC10h 24m
2026-07-05 DAL213 ATH → JFK Jul 5, 12:49 UTCJul 5, 23:08 UTC10h 19m
2026-07-05 DAL213 ATH → JFK Jul 5, 12:50 UTCJul 5, 16:15 UTC3h 25m
2026-07-05 DAL212 JFK → ATH Jul 5, 01:00 UTCJul 5, 09:45 UTC8h 45m
2026-07-04 DAL273 LIS → JFK Jul 4, 09:52 UTCJul 4, 16:51 UTC6h 59m
2026-07-04 DAL273 LIS → JFK Jul 4, 09:55 UTCJul 4, 16:55 UTC7h 0m
2026-07-04 DAL272 JFK → LIS Jul 4, 01:06 UTCJul 4, 07:32 UTC6h 26m
2026-07-04 DAL272 - Jul 4, 01:10 UTCJul 4, 02:25 UTC1h 15m
2026-07-03 DAL273 LIS → JFK Jul 3, 09:15 UTCJul 3, 16:05 UTC6h 50m
2026-07-03 DAL272 JFK → LIS Jul 3, 00:22 UTCJul 3, 06:53 UTC6h 31m
2026-07-03 DAL272 - Jul 3, 00:25 UTCJul 3, 01:35 UTC1h 10m
2026-07-02 DAL157 JFK → JFK Jul 2, 19:50 UTCJul 2, 19:55 UTC5m
2026-07-02 DAL157 ACC → JFK Jul 2, 09:35 UTCJul 2, 19:35 UTC10h 0m
2026-07-02 DAL157 ACC → JFK Jul 2, 09:35 UTCJul 2, 19:47 UTC10h 12m
2026-07-01 DAL156 - Jul 1, 20:55 UTCJul 2, 12:15 UTC15h 20m
2026-07-01 DAL273 LIS → JFK Jul 1, 09:37 UTCJul 1, 16:32 UTC6h 55m
2026-07-01 DAL273 LIS → JFK Jul 1, 09:40 UTCJul 1, 16:30 UTC6h 50m
2026-07-01 DAL272 JFK → LIS Jul 1, 00:20 UTCJul 1, 06:40 UTC6h 20m
2026-06-30 DAL49 AMS → JFK Jun 30, 18:50 UTCJun 30, 20:15 UTC1h 25m
2026-06-30 DAL49 AMS → JFK Jun 30, 12:55 UTCJun 30, 18:45 UTC5h 50m
2026-06-30 DAL236 - Jun 30, 01:25 UTCJun 30, 05:05 UTC3h 41m
2026-06-30 DAL236 TPA → AMS Jun 30, 01:24 UTCJun 30, 10:10 UTC8h 46m
2026-06-29 DAL237 - Jun 29, 13:09 UTCJun 29, 22:39 UTC9h 30m
2026-06-29 DAL237 AMS → TPA Jun 29, 13:07 UTCJun 29, 22:35 UTC9h 28m
2026-06-29 DAL144 SEA → AMS Jun 29, 01:10 UTCJun 29, 10:34 UTC9h 25m

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 N436DX page for operator, model, and routing details .

Mode-S A539C9 frequently asked

What is Mode-S code A539C9?
A539C9 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N436DX.
Where is Mode-S A539C9 registered?
Mode-S code A539C9 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 A539C9 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 A539C9, octal 51234711, decimal 10,828,233.
What flights does A539C9 operate?
Mode-S A539C9 has broadcast 20 distinct callsigns, including DAL133, DAL132, DAL273, DAL58, DAL272.