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sensors Mode-S transponder

A8540B

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N636AE · EMBRAER ERJ-145 · operated by AMERICAN AIRLINES INC

Hex
A8540B
Octal
52052013
Decimal
11,031,563
Country
US
Tail
N636AE
Type
E145
Broadcasting now · callsign PDT5866 · 36,000 ft
Flights observed
833
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:45 UTC

Current position

A8540B is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A8540B 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
PDT5974 - 12 2026-07-05
PDT5805 - 11 2026-07-03
PDT6054 - 10 2026-07-16
PDT6004 Piedmont Airlines 10 2026-07-26
PDT5884 - 10 2026-07-10
PDT5840 - 10 2026-06-29
PDT6042 - 9 2026-06-22
PDT6032 - 9 2026-06-30
PDT6127 Piedmont Airlines 8 2026-06-11
PDT6053 - 8 2026-07-18
PDT5980 Piedmont Airlines 8 2026-05-15
PDT6112 - 7 2026-06-30
PDT6074 Piedmont Airlines 7 2026-07-20
PDT6046 Piedmont Airlines 7 2026-07-25
PDT6033 - 7 2026-07-21
PDT5953 - 7 2026-07-21
PDT5942 Piedmont Airlines 7 2026-05-23
PDT5870 - 7 2026-06-14
PDT5861 - 7 2026-06-25
PDT5832 - 7 2026-07-01

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 PDT5845 BGR → PHL Jul 26, 21:50 UTCJul 26, 22:45 UTC55m
2026-07-26 PDT5845 BGR → PHL Jul 26, 19:40 UTCJul 26, 21:05 UTC1h 25m
2026-07-26 PDT6004 DAY → PHL Jul 26, 18:10 UTCJul 26, 18:30 UTC20m
2026-07-26 PDT5893 CLT → FLO Jul 26, 03:35 UTCJul 26, 03:50 UTC15m
2026-07-26 PDT5899 TYS → PHL Jul 26, 00:00 UTCJul 26, 00:40 UTC40m
2026-07-25 PDT5899 TYS → PHL Jul 25, 23:56 UTCJul 26, 00:39 UTC43m
2026-07-25 PDT5899 TYS → PHL Jul 25, 22:20 UTCJul 25, 22:50 UTC30m
2026-07-25 PDT6046 MHT → PHL Jul 25, 20:15 UTCJul 25, 20:35 UTC20m
2026-07-25 PDT6046 MHT → PHL Jul 25, 20:10 UTCJul 25, 20:34 UTC24m
2026-07-25 PDT6046 MHT → PHL Jul 25, 19:05 UTCJul 25, 19:20 UTC15m
2026-07-25 PDT5810 MHT → PHL Jul 25, 16:40 UTCJul 25, 17:40 UTC1h 0m
2026-07-25 PDT5810 MHT → PHL Jul 25, 16:38 UTCJul 25, 17:42 UTC1h 4m
2026-07-25 PDT5810 MHT → PHL Jul 25, 14:20 UTCJul 25, 15:20 UTC1h 0m
2026-07-25 PDT5897 SBY → CLT Jul 25, 12:10 UTCJul 25, 13:15 UTC1h 5m
2026-07-24 PDT5788 PHL → SYR Jul 24, 23:30 UTCJul 25, 00:30 UTC1h 0m
2026-07-24 PDT5788 PHL → SYR Jul 24, 23:24 UTCJul 25, 00:27 UTC1h 3m
2026-07-24 PDT5839 PHL → SCE Jul 24, 20:35 UTCJul 24, 21:30 UTC55m
2026-07-24 PDT5839 PHL → SCE Jul 24, 18:30 UTCJul 24, 19:25 UTC55m
2026-07-24 PDT6062 ILM → PHL Jul 24, 15:45 UTCJul 24, 16:55 UTC1h 10m
2026-07-24 PDT6062 ILM → PHL Jul 24, 15:39 UTCJul 24, 16:56 UTC1h 17m
2026-07-24 PDT6062 ILM → PHL Jul 24, 12:00 UTCJul 24, 13:10 UTC1h 10m
2026-07-24 PDT6007 LEX → PHL Jul 24, 09:10 UTCJul 24, 09:55 UTC45m
2026-07-24 PDT5931 ROA → PHL Jul 24, 04:05 UTCJul 24, 04:35 UTC30m
2026-07-24 PDT5814 BOS → MDT Jul 24, 01:50 UTCJul 24, 02:30 UTC40m
2026-07-24 PDT5814 BOS → MDT Jul 24, 00:10 UTCJul 24, 00:45 UTC35m
2026-07-23 PDT6045 PHL → ART Jul 23, 22:15 UTCJul 23, 23:00 UTC45m
2026-07-23 PDT6044 BOS → MDT Jul 23, 19:45 UTCJul 23, 21:10 UTC1h 25m
2026-07-23 PDT6044 BOS → MDT Jul 23, 19:43 UTCJul 23, 21:17 UTC1h 34m
2026-07-23 PDT5978 DTW → PHL Jul 23, 17:15 UTCJul 23, 18:10 UTC55m
2026-07-23 PDT5978 DTW → PHL Jul 23, 15:20 UTCJul 23, 16:20 UTC1h 0m
2026-07-23 PDT5901 TYS → PHL Jul 23, 12:10 UTCJul 23, 13:00 UTC50m
2026-07-23 PDT5877 SDF → PHL Jul 23, 02:25 UTCJul 23, 03:10 UTC45m
2026-07-23 PDT5877 SDF → PHL Jul 23, 02:23 UTCJul 23, 03:24 UTC1h 1m
2026-07-22 PDT5918 TVC → ORD Jul 22, 23:40 UTCJul 23, 00:10 UTC30m
2026-07-22 PDT5918 TVC → ORD Jul 22, 22:25 UTCJul 22, 22:50 UTC25m
2026-07-22 PDT6005 CLE → PHL Jul 22, 20:10 UTCJul 22, 21:05 UTC55m
2026-07-22 PDT5900 ORD → TYS Jul 22, 17:55 UTCJul 22, 18:30 UTC35m
2026-07-22 PDT5900 ORD → TYS Jul 22, 17:49 UTCJul 22, 18:28 UTC39m
2026-07-22 PDT5898 PHL → MDT Jul 22, 15:45 UTCJul 22, 16:20 UTC35m
2026-07-22 PDT5898 PHL → MDT Jul 22, 13:55 UTCJul 22, 14:40 UTC45m
2026-07-22 PDT5992 GSP → PHL Jul 22, 11:15 UTCJul 22, 11:30 UTC15m
2026-07-22 PDT5912 PHL → MDT Jul 22, 01:20 UTCJul 22, 01:45 UTC25m
2026-07-21 PDT6078 PIT → PHL Jul 21, 22:35 UTCJul 21, 23:45 UTC1h 10m
2026-07-21 PDT6078 PIT → PHL Jul 21, 19:55 UTCJul 21, 21:35 UTC1h 40m
2026-07-21 PDT5953 - Jul 21, 17:15 UTCJul 21, 17:45 UTC30m
2026-07-21 PDT5953 - Jul 21, 15:45 UTCJul 21, 16:20 UTC35m
2026-07-21 PDT6033 - Jul 21, 13:15 UTCJul 21, 13:35 UTC20m
2026-07-21 PDT6033 - Jul 21, 11:45 UTCJul 21, 12:10 UTC25m
2026-07-21 PDT6104 SYR → BOS Jul 21, 09:10 UTCJul 21, 09:50 UTC40m
2026-07-21 PDT6015 - Jul 21, 01:40 UTCJul 21, 02:15 UTC35m

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 N636AE page for operator, model, and routing details .

Mode-S A8540B frequently asked

What is Mode-S code A8540B?
A8540B is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N636AE.
Where is Mode-S A8540B registered?
Mode-S code A8540B 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 A8540B broadcasting right now?
Yes. Mode-S A8540B is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A8540B, octal 52052013, decimal 11,031,563.
What flights does A8540B operate?
Mode-S A8540B has broadcast 20 distinct callsigns, including PDT5974, PDT5805, PDT6054, PDT6004, PDT5884.