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sensors Mode-S transponder

A517DC

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N427YX · EMBRAER ERJ-170-200 (long wing) · operated by REPUBLIC AIRWAYS INC

Hex
A517DC
Octal
51213734
Decimal
10,819,548
Country
US
Tail
N427YX
Type
E75L
No current signal · last broadcast Jul 26, 19:55 UTC
Flights observed
741
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 19:55 UTC

Last known position

Most recent position reported by Mode-S A517DC.

Country allocation

The ICAO 24-bit address A517DC 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
RPA4704 Republic Airlines 13 2026-06-30
RPA4472 - 10 2026-07-13
RPA4768 - 9 2026-07-23
RPA4490 Republic Airlines 8 2026-07-18
RPA4724 - 7 2026-07-13
RPA4649 - 7 2026-07-02
RPA4607 Republic Airlines 7 2026-07-24
RPA4431 Republic Airlines 7 2026-07-21
RPA4405 - 7 2026-07-18
RPA4396 Republic Airlines 7 2026-07-07
RPA4364 Republic Airlines 7 2026-06-03
RPA4805 Republic Airlines 6 2026-06-10
RPA4754 - 6 2026-07-06
RPA4748 - 6 2026-07-13
RPA4728 - 6 2026-07-11
RPA4717 - 6 2026-06-30
RPA4666 - 6 2026-07-08
RPA4601 Republic Airlines 6 2026-06-07
RPA4553 Republic Airlines 6 2026-06-09
RPA4453 - 6 2026-07-09

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 RPA4600 LGA → PIT Jul 26, 18:15 UTCJul 26, 19:55 UTC1h 40m
2026-07-26 RPA4600 LGA → PIT Jul 26, 18:15 UTCJul 26, 19:56 UTC1h 41m
2026-07-26 RPA4783 EYW → LGA Jul 26, 12:00 UTCJul 26, 13:15 UTC1h 15m
2026-07-25 RPA4674 BOS → TVC Jul 25, 21:31 UTCJul 25, 22:53 UTC1h 22m
2026-07-25 RPA4674 BOS → TVC Jul 25, 21:35 UTCJul 25, 22:45 UTC1h 10m
2026-07-25 RPA4415 ATL → LGA Jul 25, 15:40 UTCJul 25, 16:55 UTC1h 15m
2026-07-25 RPA4415 ATL → LGA Jul 25, 13:15 UTCJul 25, 14:35 UTC1h 20m
2026-07-24 RPA4607 BOS → MEM Jul 24, 23:50 UTCJul 25, 01:20 UTC1h 30m
2026-07-24 RPA4607 BOS → MEM Jul 24, 20:50 UTCJul 24, 22:20 UTC1h 30m
2026-07-24 RPA4730 BOS → IND Jul 24, 18:25 UTCJul 24, 19:10 UTC45m
2026-07-24 RPA4730 BOS → IND Jul 24, 18:24 UTCJul 24, 19:08 UTC44m
2026-07-24 RPA4349 JFK → BOS Jul 24, 15:48 UTCJul 24, 17:05 UTC1h 17m
2026-07-24 RPA4349 JFK → BOS Jul 24, 15:50 UTCJul 24, 17:10 UTC1h 20m
2026-07-24 RPA4687 JFK → DCA Jul 24, 12:35 UTCJul 24, 14:30 UTC1h 55m
2026-07-24 RPA4687 JFK → DCA Jul 24, 12:31 UTCJul 24, 14:29 UTC1h 58m
2026-07-24 RPA4692 BNA → PHL Jul 24, 02:18 UTCJul 24, 04:28 UTC2h 10m
2026-07-24 RPA4692 BNA → PHL Jul 24, 02:20 UTCJul 24, 04:35 UTC2h 15m
2026-07-23 RPA4384 LGA → GSO Jul 23, 23:30 UTCJul 24, 01:00 UTC1h 30m
2026-07-23 RPA4384 LGA → GSO Jul 23, 23:29 UTCJul 24, 01:20 UTC1h 51m
2026-07-23 RPA4759 ORD → TVC Jul 23, 19:45 UTCJul 23, 21:20 UTC1h 35m
2026-07-23 RPA4759 ORD → TVC Jul 23, 19:45 UTCJul 23, 21:19 UTC1h 34m
2026-07-23 RPA4759 ORD → TVC Jul 23, 17:00 UTCJul 23, 18:30 UTC1h 30m
2026-07-23 RPA4443 ORD → PVD Jul 23, 14:45 UTCJul 23, 15:25 UTC40m
2026-07-23 RPA4435 BOS → IND Jul 23, 11:15 UTCJul 23, 13:40 UTC2h 25m
2026-07-23 RPA4768 LGA → BOS Jul 23, 02:30 UTCJul 23, 03:15 UTC45m
2026-07-23 RPA4768 LGA → BOS Jul 23, 02:30 UTCJul 23, 03:11 UTC41m
2026-07-22 RPA4461 JFK → ORF Jul 22, 21:45 UTCJul 23, 00:00 UTC2h 15m
2026-07-22 RPA4461 JFK → ORF Jul 22, 18:20 UTCJul 22, 20:35 UTC2h 15m
2026-07-22 RPA4645 PHL → BTV Jul 22, 16:00 UTCJul 22, 16:45 UTC45m
2026-07-22 RPA4766 - Jul 22, 12:00 UTCJul 22, 14:05 UTC2h 5m
2026-07-22 RPA4694 LGA → SDF Jul 22, 02:30 UTCJul 22, 04:55 UTC2h 25m
2026-07-21 RPA4431 JFK → CMH Jul 21, 15:30 UTCJul 21, 17:45 UTC2h 15m
2026-07-21 RPA4431 JFK → CMH Jul 21, 15:29 UTCJul 21, 17:35 UTC2h 6m
2026-07-21 RPA4431 JFK → CMH Jul 21, 12:25 UTCJul 21, 14:30 UTC2h 5m
2026-07-21 RPA4612 PHL → BNA Jul 21, 10:15 UTCJul 21, 11:05 UTC50m
2026-07-21 RPA4660 JFK → PIT Jul 21, 03:20 UTCJul 21, 04:00 UTC40m
2026-07-21 RPA4660 JFK → PIT Jul 21, 03:16 UTCJul 21, 03:59 UTC43m
2026-07-20 RPA4459 CVG → JFK Jul 20, 23:40 UTCJul 21, 01:25 UTC1h 45m
2026-07-20 RPA4459 CVG → JFK Jul 20, 23:39 UTCJul 21, 01:19 UTC1h 40m
2026-07-20 RPA4647 - Jul 20, 21:10 UTCJul 20, 22:20 UTC1h 10m
2026-07-20 RPA4647 ORD → MEM Jul 20, 21:05 UTCJul 20, 22:16 UTC1h 11m
2026-07-20 RPA4386 BOS → ORD Jul 20, 17:10 UTCJul 20, 19:30 UTC2h 20m
2026-07-20 RPA4708 - Jul 20, 15:55 UTCJul 20, 16:20 UTC25m
2026-07-20 RPA4708 ACK → BOS Jul 20, 15:52 UTCJul 20, 16:22 UTC30m
2026-07-20 RPA4708 - Jul 20, 13:55 UTCJul 20, 14:15 UTC20m
2026-07-20 RPA4714 RDU → DCA Jul 20, 11:15 UTCJul 20, 12:20 UTC1h 5m
2026-07-20 RPA4715 - Jul 20, 03:45 UTCJul 20, 04:50 UTC1h 5m
2026-07-20 RPA4715 BOS → MDT Jul 20, 03:45 UTCJul 20, 04:47 UTC1h 2m
2026-07-20 RPA4709 - Jul 20, 01:50 UTCJul 20, 02:45 UTC55m
2026-07-19 RPA4709 BOS → ROC Jul 19, 23:35 UTCJul 20, 00:35 UTC1h 0m

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 N427YX page for operator, model, and routing details .

Mode-S A517DC frequently asked

What is Mode-S code A517DC?
A517DC is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N427YX.
Where is Mode-S A517DC registered?
Mode-S code A517DC 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 A517DC broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 19:55 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A517DC, octal 51213734, decimal 10,819,548.
What flights does A517DC operate?
Mode-S A517DC has broadcast 20 distinct callsigns, including RPA4704, RPA4472, RPA4768, RPA4490, RPA4724.