Apparatus

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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 1h ago
Flights observed
654
Distinct callsigns
20
Country
US
Last broadcast
1h ago

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 Republic Airlines 7 2026-04-23
RPA4724 - 7 2026-07-13
RPA4649 - 7 2026-07-02
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
RPA4490 Republic Airlines 6 2026-05-04
RPA4453 - 6 2026-07-09
RPA4747 Republic Airlines 5 2026-06-14
RPA4710 - 5 2026-07-01
RPA4626 - 5 2026-07-02

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 RPA4663 ORD → BWI Jul 14, 03:00 UTCJul 14, 04:25 UTC1h 25m
2026-07-13 RPA4724 OMA → ORD Jul 13, 23:30 UTCJul 14, 01:10 UTC1h 40m
2026-07-13 RPA4724 - Jul 13, 21:20 UTCJul 13, 22:15 UTC55m
2026-07-13 RPA4748 - Jul 13, 19:30 UTCJul 13, 19:55 UTC25m
2026-07-13 RPA4748 - Jul 13, 17:40 UTCJul 13, 19:55 UTC2h 15m
2026-07-13 RPA4748 MSY → ORD Jul 13, 17:39 UTCJul 13, 19:11 UTC1h 32m
2026-07-13 RPA4748 - Jul 13, 14:25 UTCJul 13, 16:20 UTC1h 55m
2026-07-13 RPA4444 - Jul 13, 11:15 UTCJul 13, 12:20 UTC1h 5m
2026-07-13 RPA4472 - Jul 13, 03:50 UTCJul 13, 04:50 UTC1h 0m
2026-07-13 RPA4472 ORD → MSP Jul 13, 03:50 UTCJul 13, 04:46 UTC56m
2026-07-13 RPA4455 - Jul 13, 01:05 UTCJul 13, 02:01 UTC55m
2026-07-12 RPA4462 LGA → CMH Jul 12, 21:46 UTCJul 12, 23:00 UTC1h 14m
2026-07-12 RPA4462 LGA → CMH Jul 12, 21:45 UTCJul 12, 23:00 UTC1h 15m
2026-07-12 RPA4620 - Jul 12, 16:01 UTCJul 12, 18:40 UTC2h 40m
2026-07-12 RPA4620 LGA → XNA Jul 12, 11:45 UTCJul 12, 14:10 UTC2h 25m
2026-07-12 RPA4605 ATL → LGA Jul 12, 03:30 UTCJul 12, 05:20 UTC1h 50m
2026-07-11 RPA4605 - Jul 11, 23:15 UTCJul 11, 23:45 UTC30m
2026-07-11 RPA4605 - Jul 11, 17:15 UTCJul 11, 19:35 UTC2h 20m
2026-07-11 RPA4669 STL → LGA Jul 11, 11:55 UTCJul 11, 13:50 UTC1h 55m
2026-07-11 RPA4728 - Jul 11, 05:25 UTCJul 11, 06:01 UTC35m
2026-07-11 RPA4728 LGA → STL Jul 11, 02:55 UTCJul 11, 05:08 UTC2h 13m
2026-07-11 RPA4728 LGA → STL Jul 11, 02:55 UTCJul 11, 06:01 UTC3h 5m
2026-07-10 RPA4619 - Jul 10, 19:20 UTCJul 10, 22:00 UTC2h 40m
2026-07-10 RPA4619 LGA → TUL Jul 10, 15:15 UTCJul 10, 18:05 UTC2h 50m
2026-07-10 RPA4581 - Jul 10, 11:15 UTCJul 10, 14:10 UTC2h 55m
2026-07-10 RPA9947 - Jul 10, 01:30 UTCJul 10, 03:30 UTC2h 0m
2026-07-09 RPA4453 JFK → CLE Jul 9, 17:13 UTCJul 9, 18:26 UTC1h 13m
2026-07-09 RPA4453 JFK → CLE Jul 9, 17:15 UTCJul 9, 18:30 UTC1h 15m
2026-07-09 RPA4476 - Jul 9, 14:45 UTCJul 9, 15:55 UTC1h 10m
2026-07-09 RPA4476 CLE → JFK Jul 9, 14:40 UTCJul 9, 15:52 UTC1h 12m
2026-07-09 RPA4387 LGA → CLE Jul 9, 12:39 UTCJul 9, 13:44 UTC1h 5m
2026-07-09 RPA4387 LGA → CLE Jul 9, 12:40 UTCJul 9, 13:45 UTC1h 5m
2026-07-09 RPA4693 ORF → LGA Jul 9, 10:10 UTCJul 9, 11:05 UTC55m
2026-07-09 RPA4693 ORF → LGA Jul 9, 10:08 UTCJul 9, 11:04 UTC56m
2026-07-09 RPA4589 LGA → ORF Jul 9, 00:50 UTCJul 9, 02:00 UTC1h 10m
2026-07-09 RPA4589 LGA → ORF Jul 9, 00:48 UTCJul 9, 01:56 UTC1h 8m
2026-07-08 RPA4437 - Jul 8, 21:55 UTCJul 8, 23:35 UTC1h 40m
2026-07-08 RPA4636 BOS → IND Jul 8, 17:45 UTCJul 8, 19:40 UTC1h 55m
2026-07-08 RPA4666 - Jul 8, 15:45 UTCJul 8, 16:50 UTC1h 5m
2026-07-08 RPA4666 BOS → BUF Jul 8, 13:30 UTCJul 8, 14:35 UTC1h 5m
2026-07-08 RPA4788 BUF → BOS Jul 8, 11:25 UTCJul 8, 12:25 UTC1h 0m
2026-07-08 RPA4788 BUF → BOS Jul 8, 11:20 UTCJul 8, 12:24 UTC1h 4m
2026-07-08 RPA4521 LGA → BUF Jul 8, 00:15 UTCJul 8, 01:05 UTC50m
2026-07-07 RPA4509 STL → LGA Jul 7, 20:25 UTCJul 7, 22:45 UTC2h 20m
2026-07-07 RPA4509 LGA → STL Jul 7, 17:25 UTCJul 7, 19:25 UTC2h 0m
2026-07-07 RPA4373 BOS → LGA Jul 7, 15:35 UTCJul 7, 16:25 UTC50m
2026-07-07 RPA4373 BOS → LGA Jul 7, 15:31 UTCJul 7, 16:22 UTC51m
2026-07-07 RPA4373 - Jul 7, 14:10 UTCJul 7, 14:45 UTC35m
2026-07-07 RPA4396 PWM → PHL Jul 7, 12:25 UTCJul 7, 13:15 UTC50m
2026-07-07 RPA9942 JFK → BOS Jul 7, 05:20 UTCJul 7, 05:55 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 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 1h ago.
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, RPA4724, RPA4649.