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sensors Mode-S transponder

A0634C

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N124HQ · EMBRAER ERJ-170-200 (long wing) · operated by REPUBLIC AIRWAYS INC

Hex
A0634C
Octal
50061514
Decimal
10,511,180
Country
US
Tail
N124HQ
Type
E75L
No current signal · last broadcast Jul 26, 01:45 UTC
Flights observed
747
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 01:45 UTC

Last known position

Most recent position reported by Mode-S A0634C.

Country allocation

The ICAO 24-bit address A0634C 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
RPA4524 - 14 2026-06-24
RPA4774 - 10 2026-07-16
RPA4620 - 9 2026-07-09
RPA4768 Republic Airlines 8 2026-05-19
RPA4596 - 8 2026-07-05
RPA4342 - 8 2026-07-19
RPA4565 - 7 2026-07-07
RPA4521 - 7 2026-07-14
RPA4493 Republic Airlines 7 2026-07-20
RPA4422 - 7 2026-07-20
RPA4719 Republic Airlines 6 2026-06-17
RPA4647 - 6 2026-07-01
RPA4616 - 6 2026-07-20
RPA4552 Republic Airlines 6 2026-06-14
RPA4510 Republic Airlines 6 2026-04-30
RPA4478 Republic Airlines 6 2026-07-23
RPA4470 - 6 2026-06-21
RPA4436 - 6 2026-07-10
RPA4428 - 6 2026-06-24
RPA4392 Republic Airlines 6 2026-05-06

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 RPA4611 JFK → PIT Jul 26, 00:49 UTCJul 26, 01:31 UTC42m
2026-07-26 RPA4611 JFK → PIT Jul 26, 00:50 UTCJul 26, 01:45 UTC55m
2026-07-25 RPA4389 DCA → PVD Jul 25, 21:10 UTCJul 25, 22:20 UTC1h 10m
2026-07-25 RPA4389 DCA → PVD Jul 25, 18:50 UTCJul 25, 20:00 UTC1h 10m
2026-07-25 RPA4366 DCA → MEM Jul 25, 16:30 UTCJul 25, 17:15 UTC45m
2026-07-25 RPA4716 IND → BOS Jul 25, 13:10 UTCJul 25, 15:00 UTC1h 50m
2026-07-24 RPA4449 JFK → IND Jul 24, 23:05 UTCJul 25, 00:45 UTC1h 40m
2026-07-24 RPA9931 IND → PIT Jul 24, 20:10 UTCJul 24, 20:50 UTC40m
2026-07-24 RPA4543 DCA → MSY Jul 24, 13:00 UTCJul 24, 14:00 UTC1h 0m
2026-07-24 RPA4351 CLE → ORD Jul 24, 10:20 UTCJul 24, 11:40 UTC1h 20m
2026-07-24 RPA4403 GSO → LGA Jul 24, 02:45 UTCJul 24, 04:30 UTC1h 45m
2026-07-24 RPA4403 GSO → LGA Jul 24, 02:40 UTCJul 24, 04:32 UTC1h 52m
2026-07-23 RPA4426 RIC → PHL Jul 23, 22:40 UTCJul 24, 01:05 UTC2h 25m
2026-07-23 RPA4426 RIC → PHL Jul 23, 19:05 UTCJul 23, 21:10 UTC2h 5m
2026-07-23 RPA4478 IAH → PHL Jul 23, 15:50 UTCJul 23, 16:55 UTC1h 5m
2026-07-23 RPA4478 IAH → PHL Jul 23, 13:25 UTCJul 23, 14:25 UTC1h 0m
2026-07-23 RPA4622 JFK → BOS Jul 23, 11:00 UTCJul 23, 12:10 UTC1h 10m
2026-07-23 RPA4622 JFK → BOS Jul 23, 10:59 UTCJul 23, 12:01 UTC1h 2m
2026-07-23 RPA4466 PHL → SDF Jul 23, 03:10 UTCJul 23, 04:45 UTC1h 35m
2026-07-22 RPA4749 PHL → DCA Jul 22, 23:35 UTCJul 23, 00:15 UTC40m
2026-07-22 RPA4749 PHL → DCA Jul 22, 21:50 UTCJul 22, 22:45 UTC55m
2026-07-22 RPA4430 IND → DCA Jul 22, 16:55 UTCJul 22, 17:55 UTC1h 0m
2026-07-22 RPA4561 - Jul 22, 15:05 UTCJul 22, 16:00 UTC55m
2026-07-22 RPA4613 - Jul 22, 12:15 UTCJul 22, 13:30 UTC1h 15m
2026-07-21 RPA9695 CMH → TUL Jul 21, 21:35 UTCJul 21, 22:05 UTC30m
2026-07-21 RPA4360 BTV → DCA Jul 21, 12:50 UTCJul 21, 14:40 UTC1h 50m
2026-07-21 RPA4529 - Jul 21, 10:35 UTCJul 21, 11:15 UTC40m
2026-07-21 RPA4529 PIT → DCA Jul 21, 10:30 UTCJul 21, 11:15 UTC45m
2026-07-20 RPA4493 LGA → BNA Jul 20, 23:10 UTCJul 21, 00:00 UTC50m
2026-07-20 RPA4493 LGA → BNA Jul 20, 21:15 UTCJul 20, 22:05 UTC50m
2026-07-20 RPA4479 - Jul 20, 17:55 UTCJul 20, 18:50 UTC55m
2026-07-20 RPA4422 - Jul 20, 15:10 UTCJul 20, 16:35 UTC1h 25m
2026-07-20 RPA4422 - Jul 20, 12:20 UTCJul 20, 13:45 UTC1h 25m
2026-07-20 RPA4522 PHL → SDF Jul 20, 10:10 UTCJul 20, 11:00 UTC50m
2026-07-20 RPA4616 BOS → BUF Jul 20, 00:45 UTCJul 20, 01:50 UTC1h 5m
2026-07-20 RPA4616 BOS → BUF Jul 20, 00:44 UTCJul 20, 01:46 UTC1h 2m
2026-07-19 RPA4374 LGA → BOS Jul 19, 22:35 UTCJul 19, 23:10 UTC35m
2026-07-19 RPA4374 LGA → BOS Jul 19, 22:34 UTCJul 19, 22:57 UTC23m
2026-07-19 RPA4342 - Jul 19, 20:15 UTCJul 19, 21:35 UTC1h 20m
2026-07-19 RPA4342 - Jul 19, 17:30 UTCJul 19, 19:10 UTC1h 40m
2026-07-19 RPA4581 MEM → LGA Jul 19, 13:20 UTCJul 19, 16:00 UTC2h 40m
2026-07-19 RPA4581 MEM → LGA Jul 19, 13:18 UTCJul 19, 16:00 UTC2h 42m
2026-07-19 RPA4547 RDU → LGA Jul 19, 04:15 UTCJul 19, 06:40 UTC2h 25m
2026-07-19 RPA4547 RDU → LGA Jul 19, 04:15 UTCJul 19, 06:37 UTC2h 22m
2026-07-19 RPA4395 - Jul 19, 00:30 UTCJul 19, 03:00 UTC2h 30m
2026-07-19 RPA4395 OKC → MIA Jul 19, 00:28 UTCJul 19, 02:58 UTC2h 30m
2026-07-18 RPA4395 - Jul 18, 20:45 UTCJul 18, 23:30 UTC2h 45m
2026-07-18 RPA4800 - Jul 18, 16:30 UTCJul 18, 19:30 UTC3h 0m
2026-07-18 RPA9931 - Jul 18, 14:45 UTCJul 18, 15:30 UTC45m
2026-07-18 RPA4391 - Jul 18, 11:05 UTCJul 18, 13:15 UTC2h 10m

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 N124HQ page for operator, model, and routing details .

Mode-S A0634C frequently asked

What is Mode-S code A0634C?
A0634C is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N124HQ.
Where is Mode-S A0634C registered?
Mode-S code A0634C 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 A0634C broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 01:45 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A0634C, octal 50061514, decimal 10,511,180.
What flights does A0634C operate?
Mode-S A0634C has broadcast 20 distinct callsigns, including RPA4524, RPA4774, RPA4620, RPA4768, RPA4596.