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sensors Mode-S transponder

A4C8DE

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N407YX · EMBRAER ERJ-170-200 (long wing) · operated by REPUBLIC AIRWAYS INC

Hex
A4C8DE
Octal
51144336
Decimal
10,799,326
Country
US
Tail
N407YX
Type
E75L
No current signal · last broadcast Jul 26, 21:30 UTC
Flights observed
765
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:30 UTC

Last known position

Most recent position reported by Mode-S A4C8DE.

Country allocation

The ICAO 24-bit address A4C8DE 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
RPA4754 - 9 2026-07-15
RPA4679 Republic Airlines 8 2026-07-24
RPA4449 Republic Airlines 8 2026-06-09
RPA4581 - 7 2026-07-05
RPA4539 Republic Airlines 7 2026-07-21
RPA4489 - 7 2026-07-21
RPA4481 Republic Airlines 7 2026-07-22
RPA4380 - 7 2026-07-06
RPA4774 - 6 2026-06-25
RPA4717 - 6 2026-07-14
RPA4709 - 6 2026-06-29
RPA4590 - 6 2026-07-20
RPA4584 Republic Airlines 6 2026-07-23
RPA4575 Republic Airlines 6 2026-07-19
RPA4518 - 6 2026-07-11
RPA4460 Republic Airlines 6 2026-07-24
RPA4454 Republic Airlines 6 2026-04-28
RPA4452 - 6 2026-06-26
RPA4436 - 6 2026-07-15
RPA4413 - 6 2026-07-13

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 RPA4724 IND → BOS Jul 26, 21:20 UTCJul 26, 21:30 UTC10m
2026-07-26 RPA4386 DCA → DSM Jul 26, 17:20 UTCJul 26, 19:30 UTC2h 10m
2026-07-26 RPA4635 ORD → LGA Jul 26, 15:30 UTCJul 26, 16:15 UTC45m
2026-07-26 RPA4635 ORD → LGA Jul 26, 15:28 UTCJul 26, 16:18 UTC50m
2026-07-26 RPA4635 ORD → LGA Jul 26, 13:35 UTCJul 26, 14:15 UTC40m
2026-07-26 RPA4642 DCA → PVD Jul 26, 10:55 UTCJul 26, 12:35 UTC1h 40m
2026-07-25 RPA4767 JFK → CMH Jul 25, 19:10 UTCJul 25, 20:25 UTC1h 15m
2026-07-25 RPA4408 YYZ → ORD Jul 25, 16:05 UTCJul 25, 17:35 UTC1h 30m
2026-07-25 RPA4408 YYZ → ORD Jul 25, 13:15 UTCJul 25, 14:50 UTC1h 35m
2026-07-25 RPA4551 DCA → JAX Jul 25, 10:40 UTCJul 25, 11:25 UTC45m
2026-07-24 RPA4459 CVG → JFK Jul 24, 23:40 UTCJul 25, 01:30 UTC1h 50m
2026-07-24 RPA4459 CVG → JFK Jul 24, 23:34 UTCJul 25, 01:31 UTC1h 57m
2026-07-24 RPA4460 SAV → PHL Jul 24, 20:33 UTCJul 24, 22:24 UTC1h 51m
2026-07-24 RPA4460 SAV → PHL Jul 24, 20:35 UTCJul 24, 22:20 UTC1h 45m
2026-07-24 RPA4523 LGA → MSP Jul 24, 17:45 UTCJul 24, 19:20 UTC1h 35m
2026-07-24 RPA4523 LGA → MSP Jul 24, 17:44 UTCJul 24, 19:13 UTC1h 29m
2026-07-24 RPA4523 LGA → MSP Jul 24, 15:15 UTCJul 24, 16:55 UTC1h 40m
2026-07-24 RPA4737 DCA → BOS Jul 24, 12:55 UTCJul 24, 13:55 UTC1h 0m
2026-07-24 RPA4737 DCA → BOS Jul 24, 12:54 UTCJul 24, 13:49 UTC55m
2026-07-24 RPA4737 DCA → BOS Jul 24, 10:55 UTCJul 24, 11:50 UTC55m
2026-07-24 RPA4679 JFK → IND Jul 24, 01:10 UTCJul 24, 02:15 UTC1h 5m
2026-07-24 RPA4679 JFK → IND Jul 24, 01:08 UTCJul 24, 02:12 UTC1h 4m
2026-07-23 RPA4679 JFK → IND Jul 23, 23:10 UTCJul 24, 00:10 UTC1h 0m
2026-07-23 RPA4584 LGA → CHO Jul 23, 20:35 UTCJul 23, 21:40 UTC1h 5m
2026-07-23 RPA4584 LGA → CHO Jul 23, 17:55 UTCJul 23, 19:05 UTC1h 10m
2026-07-23 RPA4543 DCA → MSY Jul 23, 15:05 UTCJul 23, 16:35 UTC1h 30m
2026-07-23 RPA4543 DCA → MSY Jul 23, 13:05 UTCJul 23, 13:55 UTC50m
2026-07-23 RPA4549 SDF → DCA Jul 23, 10:10 UTCJul 23, 11:20 UTC1h 10m
2026-07-23 RPA4549 SDF → DCA Jul 23, 10:08 UTCJul 23, 11:14 UTC1h 6m
2026-07-23 RPA4603 ORD → SDF Jul 23, 00:40 UTCJul 23, 01:30 UTC50m
2026-07-22 RPA4534 PIT → PHL Jul 22, 20:55 UTCJul 22, 22:55 UTC2h 0m
2026-07-22 RPA4534 PIT → PHL Jul 22, 18:10 UTCJul 22, 19:50 UTC1h 40m
2026-07-22 RPA407 JFK → IND Jul 22, 15:50 UTCJul 22, 17:05 UTC1h 15m
2026-07-22 RPA4532 DCA → PIT Jul 22, 12:55 UTCJul 22, 13:50 UTC55m
2026-07-22 RPA4532 DCA → PIT Jul 22, 12:53 UTCJul 22, 13:49 UTC56m
2026-07-22 RPA4494 BOS → DCA Jul 22, 11:10 UTCJul 22, 11:55 UTC45m
2026-07-22 RPA4481 JFK → RDU Jul 22, 00:15 UTCJul 22, 02:20 UTC2h 5m
2026-07-22 RPA4481 JFK → RDU Jul 22, 00:17 UTCJul 22, 02:13 UTC1h 56m
2026-07-21 RPA4489 RDU → BNA Jul 21, 20:15 UTCJul 21, 21:30 UTC1h 15m
2026-07-21 RPA4489 RDU → BNA Jul 21, 20:14 UTCJul 21, 21:29 UTC1h 15m
2026-07-21 RPA4639 BNA → RDU Jul 21, 17:15 UTCJul 21, 18:30 UTC1h 15m
2026-07-21 RPA4344 ORD → BOS Jul 21, 14:15 UTCJul 21, 15:25 UTC1h 10m
2026-07-21 RPA4344 ORD → BOS Jul 21, 14:12 UTCJul 21, 15:23 UTC1h 11m
2026-07-21 RPA4531 PIT → RDU Jul 21, 12:10 UTCJul 21, 13:05 UTC55m
2026-07-21 RPA4531 PIT → RDU Jul 21, 12:09 UTCJul 21, 12:47 UTC38m
2026-07-21 RPA4539 MEM → LGA Jul 21, 02:50 UTCJul 21, 03:50 UTC1h 0m
2026-07-21 RPA4539 MEM → LGA Jul 21, 02:47 UTCJul 21, 03:46 UTC59m
2026-07-20 RPA4457 - Jul 20, 23:25 UTCJul 21, 01:10 UTC1h 44m
2026-07-20 RPA4460 DCA → MEM Jul 20, 20:15 UTCJul 20, 22:00 UTC1h 45m
2026-07-20 RPA4590 LGA → DCA Jul 20, 18:25 UTCJul 20, 19:10 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 N407YX page for operator, model, and routing details .

Mode-S A4C8DE frequently asked

What is Mode-S code A4C8DE?
A4C8DE is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N407YX.
Where is Mode-S A4C8DE registered?
Mode-S code A4C8DE 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 A4C8DE broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 21:30 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A4C8DE, octal 51144336, decimal 10,799,326.
What flights does A4C8DE operate?
Mode-S A4C8DE has broadcast 20 distinct callsigns, including RPA4754, RPA4679, RPA4449, RPA4581, RPA4539.