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sensors Mode-S transponder

A8C439

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N664MS · EMBRAER ERJ-145 · operated by AMERICAN AIRLINES INC

Hex
A8C439
Octal
52142071
Decimal
11,060,281
Country
US
Tail
N664MS
Type
E145
No current signal · last broadcast Jul 21, 17:15 UTC
Flights observed
793
Distinct callsigns
20
Country
US
Last broadcast
Jul 21, 17:15 UTC

Last known position

Most recent position reported by Mode-S A8C439.

Country allocation

The ICAO 24-bit address A8C439 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
PDT5824 - 12 2026-07-02
PDT5835 - 10 2026-07-03
PDT5817 - 10 2026-07-01
PDT6127 - 9 2026-06-22
PDT6062 Piedmont Airlines 9 2026-05-27
PDT5918 - 9 2026-06-24
PDT5813 Piedmont Airlines 9 2026-06-06
PDT6105 Piedmont Airlines 8 2026-06-06
PDT5989 - 8 2026-07-11
PDT5910 - 8 2026-07-11
PDT5902 - 8 2026-06-22
PDT5865 - 8 2026-07-08
PDT6122 - 7 2026-06-28
PDT6120 Piedmont Airlines 7 2026-06-11
PDT6065 Piedmont Airlines 7 2026-06-03
PDT6048 - 7 2026-07-03
PDT6028 - 7 2026-06-23
PDT5990 Piedmont Airlines 7 2026-06-04
PDT5955 Piedmont Airlines 7 2026-06-08
PDT5803 Piedmont Airlines 7 2026-06-01

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-21 PDT9975 CLT → ALO Jul 21, 14:05 UTCJul 21, 17:15 UTC3h 10m
2026-07-20 PDT6084 - Jul 20, 00:30 UTCJul 20, 01:50 UTC1h 20m
2026-07-20 PDT6084 CAE → PHL Jul 20, 00:25 UTCJul 20, 01:46 UTC1h 21m
2026-07-19 PDT6044 BOS → MDT Jul 19, 21:55 UTCJul 19, 23:35 UTC1h 40m
2026-07-19 PDT6044 BOS → MDT Jul 19, 19:50 UTCJul 19, 20:15 UTC25m
2026-07-19 PDT6011 YUL → PHL Jul 19, 17:20 UTCJul 19, 18:25 UTC1h 5m
2026-07-19 PDT6011 YUL → PHL Jul 19, 17:19 UTCJul 19, 18:26 UTC1h 7m
2026-07-19 PDT6011 YUL → PHL Jul 19, 14:45 UTCJul 19, 16:05 UTC1h 20m
2026-07-19 PDT5887 YYZ → PHL Jul 19, 12:30 UTCJul 19, 13:25 UTC55m
2026-07-18 PDT5884 YYZ → PHL Jul 18, 20:10 UTCJul 18, 21:10 UTC1h 0m
2026-07-18 PDT5982 - Jul 18, 17:55 UTCJul 18, 18:45 UTC50m
2026-07-18 PDT5982 SYR → PHL Jul 18, 17:50 UTCJul 18, 18:43 UTC53m
2026-07-18 PDT5982 - Jul 18, 15:50 UTCJul 18, 17:00 UTC1h 10m
2026-07-17 PDT6108 ROC → PHL Jul 17, 00:35 UTCJul 17, 01:15 UTC40m
2026-07-17 PDT6108 ROC → PHL Jul 17, 00:30 UTCJul 17, 01:13 UTC43m
2026-07-16 PDT6108 - Jul 16, 22:05 UTCJul 16, 22:55 UTC50m
2026-07-16 PDT5837 - Jul 16, 00:40 UTCJul 16, 01:25 UTC45m
2026-07-16 PDT5837 SYR → PHL Jul 16, 00:34 UTCJul 16, 01:19 UTC45m
2026-07-15 PDT5837 - Jul 15, 22:35 UTCJul 15, 23:45 UTC1h 10m
2026-07-15 PDT6133 - Jul 15, 20:35 UTCJul 15, 21:40 UTC1h 5m
2026-07-15 PDT6133 ILM → PHL Jul 15, 20:26 UTCJul 15, 21:33 UTC1h 7m
2026-07-15 PDT6133 - Jul 15, 17:40 UTCJul 15, 18:35 UTC55m
2026-07-14 PDT5849 - Jul 14, 23:10 UTCJul 15, 00:40 UTC1h 30m
2026-07-14 PDT5849 - Jul 14, 20:20 UTCJul 14, 21:20 UTC1h 0m
2026-07-14 PDT5997 - Jul 14, 14:55 UTCJul 14, 15:40 UTC45m
2026-07-14 PDT5997 - Jul 14, 13:25 UTCJul 14, 14:10 UTC45m
2026-07-14 PDT5973 - Jul 14, 10:40 UTCJul 14, 11:25 UTC45m
2026-07-13 PDT5969 - Jul 13, 22:55 UTCJul 13, 23:35 UTC40m
2026-07-13 PDT5974 - Jul 13, 20:40 UTCJul 13, 21:30 UTC50m
2026-07-13 PDT5974 - Jul 13, 18:30 UTCJul 13, 19:15 UTC45m
2026-07-13 PDT6121 - Jul 13, 16:40 UTCJul 13, 17:25 UTC45m
2026-07-13 PDT6121 PHL → ORF Jul 13, 15:00 UTCJul 13, 15:45 UTC45m
2026-07-13 PDT6111 - Jul 13, 10:25 UTCJul 13, 11:15 UTC50m
2026-07-12 PDT6107 - Jul 12, 23:55 UTCJul 13, 00:50 UTC55m
2026-07-12 PDT6025 YUL → PHL Jul 12, 20:35 UTCJul 12, 21:40 UTC1h 5m
2026-07-12 PDT6023 PHL → YUL Jul 12, 17:50 UTCJul 12, 19:05 UTC1h 15m
2026-07-12 PDT6124 - Jul 12, 15:25 UTCJul 12, 16:35 UTC1h 10m
2026-07-12 PDT6124 - Jul 12, 13:20 UTCJul 12, 14:20 UTC1h 0m
2026-07-12 PDT6013 - Jul 12, 11:30 UTCJul 12, 11:55 UTC25m
2026-07-11 PDT5989 - Jul 11, 22:50 UTCJul 11, 23:50 UTC1h 0m
2026-07-11 PDT6069 - Jul 11, 19:30 UTCJul 11, 20:10 UTC40m
2026-07-11 PDT6069 - Jul 11, 17:30 UTCJul 11, 18:05 UTC35m
2026-07-11 PDT5910 - Jul 11, 15:15 UTCJul 11, 16:00 UTC45m
2026-07-11 PDT5910 - Jul 11, 12:50 UTCJul 11, 13:30 UTC40m
2026-07-11 PDT6087 - Jul 11, 10:25 UTCJul 11, 11:35 UTC1h 10m
2026-07-11 PDT5961 - Jul 11, 01:15 UTCJul 11, 02:30 UTC1h 15m
2026-07-11 PDT5961 CLT → FWA Jul 11, 01:10 UTCJul 11, 02:34 UTC1h 24m
2026-07-10 PDT6078 - Jul 10, 22:40 UTCJul 10, 23:55 UTC1h 15m
2026-07-10 PDT6078 - Jul 10, 20:35 UTCJul 10, 21:35 UTC1h 0m
2026-07-10 PDT5890 - Jul 10, 17:15 UTCJul 10, 18:00 UTC45m

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 N664MS page for operator, model, and routing details .

Mode-S A8C439 frequently asked

What is Mode-S code A8C439?
A8C439 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N664MS.
Where is Mode-S A8C439 registered?
Mode-S code A8C439 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 A8C439 broadcasting right now?
No active broadcast right now. Last signal was Jul 21, 17:15 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A8C439, octal 52142071, decimal 11,060,281.
What flights does A8C439 operate?
Mode-S A8C439 has broadcast 20 distinct callsigns, including PDT5824, PDT5835, PDT5817, PDT6127, PDT6062.