Apparatus

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sensors Mode-S transponder

A19DFF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N203JQ · EMBRAER ERJ-170-200 (long wing) · operated by REPUBLIC AIRWAYS INC

Hex
A19DFF
Octal
50316777
Decimal
10,591,743
Country
US
Tail
N203JQ
Type
E75L
No current signal · last broadcast 17d ago
Flights observed
530
Distinct callsigns
20
Country
US
Last broadcast
17d ago

Last known position

Most recent position reported by Mode-S A19DFF.

Country allocation

The ICAO 24-bit address A19DFF 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
RPA5703 Republic Airlines 9 2026-06-01
RPA5689 - 9 2026-06-19
RPA5675 Republic Airlines 9 2026-06-05
RPA5829 Republic Airlines 8 2026-05-26
RPA5758 Republic Airlines 7 2026-06-02
RPA5682 Republic Airlines 7 2026-06-05
RPA5672 Republic Airlines 7 2026-05-19
RPA5641 - 7 2026-06-23
RPA5640 Republic Airlines 7 2026-05-06
RPA5628 Republic Airlines 7 2026-05-27
RPA5846 Republic Airlines 6 2026-05-01
RPA5790 - 6 2026-06-24
RPA5744 - 6 2026-06-17
RPA5649 - 6 2026-06-22
RPA5622 - 6 2026-06-19
RPA5621 - 6 2026-06-23
RPA5604 - 6 2026-06-18
RPA5852 Republic Airlines 5 2026-06-04
RPA5807 Republic Airlines 5 2026-05-07
RPA5806 Republic Airlines 5 2026-06-06

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-06-26 RPA5873 - Jun 26, 10:39 UTCJun 26, 11:24 UTC45m
2026-06-25 RPA5616 BOS → IND Jun 25, 22:04 UTCJun 26, 00:10 UTC2h 5m
2026-06-25 RPA5727 LGA → BOS Jun 25, 19:24 UTCJun 25, 19:59 UTC35m
2026-06-25 RPA5748 - Jun 25, 17:25 UTCJun 25, 18:19 UTC55m
2026-06-25 RPA5745 LGA → BOS Jun 25, 15:15 UTCJun 25, 15:54 UTC40m
2026-06-25 RPA5660 - Jun 25, 12:19 UTCJun 25, 13:55 UTC1h 35m
2026-06-25 RPA5696 LGA → IND Jun 25, 00:24 UTCJun 25, 01:59 UTC1h 35m
2026-06-24 RPA5763 DCA → LGA Jun 24, 22:23 UTCJun 24, 23:06 UTC43m
2026-06-24 RPA5763 DCA → LGA Jun 24, 22:25 UTCJun 24, 23:14 UTC50m
2026-06-24 RPA5699 JFK → DCA Jun 24, 20:04 UTCJun 24, 20:49 UTC45m
2026-06-24 RPA5699 JFK → DCA Jun 24, 20:05 UTCJun 24, 21:00 UTC55m
2026-06-24 RPA5859 MVY → JFK Jun 24, 17:29 UTCJun 24, 18:15 UTC45m
2026-06-24 RPA5859 JFK → MVY Jun 24, 15:35 UTCJun 24, 16:14 UTC40m
2026-06-24 RPA5720 BOS → JFK Jun 24, 13:50 UTCJun 24, 14:34 UTC45m
2026-06-24 RPA5790 - Jun 24, 10:10 UTCJun 24, 11:50 UTC1h 40m
2026-06-24 RPA5790 CVG → BOS Jun 24, 10:05 UTCJun 24, 11:49 UTC1h 44m
2026-06-24 RPA5801 ORF → LGA Jun 24, 02:15 UTCJun 24, 04:10 UTC1h 55m
2026-06-23 RPA5641 - Jun 23, 23:55 UTCJun 24, 01:19 UTC1h 25m
2026-06-23 RPA5641 CLE → BOS Jun 23, 23:51 UTCJun 24, 01:15 UTC1h 24m
2026-06-23 RPA5641 BOS → CLE Jun 23, 19:15 UTCJun 23, 20:49 UTC1h 35m
2026-06-23 RPA5861 - Jun 23, 16:24 UTCJun 23, 17:59 UTC1h 35m
2026-06-23 RPA5621 LGA → TVC Jun 23, 13:09 UTCJun 23, 14:36 UTC1h 27m
2026-06-23 RPA5621 - Jun 23, 13:09 UTCJun 23, 14:39 UTC1h 30m
2026-06-23 RPA5700 - Jun 23, 10:15 UTCJun 23, 11:35 UTC1h 20m
2026-06-23 RPA5700 CMH → LGA Jun 23, 10:14 UTCJun 23, 11:37 UTC1h 23m
2026-06-22 RPA5650 JFK → CMH Jun 22, 22:10 UTCJun 22, 23:35 UTC1h 25m
2026-06-22 RPA5649 - Jun 22, 19:29 UTCJun 22, 20:55 UTC1h 25m
2026-06-22 RPA5649 CMH → JFK Jun 22, 19:28 UTCJun 22, 20:58 UTC1h 30m
2026-06-22 RPA5649 - Jun 22, 14:19 UTCJun 22, 15:40 UTC1h 20m
2026-06-22 RPA5656 LGA → BOS Jun 22, 11:14 UTCJun 22, 12:34 UTC1h 20m
2026-06-22 RPA5656 LGA → BOS Jun 22, 11:14 UTCJun 22, 12:27 UTC1h 13m
2026-06-21 RPA5671 LGA → CMH Jun 21, 21:44 UTCJun 21, 23:05 UTC1h 20m
2026-06-21 RPA5736 BOS → LGA Jun 21, 20:00 UTCJun 21, 20:40 UTC40m
2026-06-21 RPA5861 - Jun 21, 16:14 UTCJun 21, 17:39 UTC1h 25m
2026-06-21 RPA5621 - Jun 21, 13:04 UTCJun 21, 14:40 UTC1h 35m
2026-06-21 RPA5621 LGA → TVC Jun 21, 13:02 UTCJun 21, 14:49 UTC1h 47m
2026-06-21 RPA5811 - Jun 21, 10:44 UTCJun 21, 11:30 UTC45m
2026-06-20 RPA5760 LGA → RIC Jun 20, 21:38 UTCJun 20, 22:36 UTC58m
2026-06-20 RPA5760 - Jun 20, 21:40 UTCJun 20, 22:35 UTC55m
2026-06-20 RPA5726 BOS → LGA Jun 20, 19:15 UTCJun 20, 20:00 UTC45m
2026-06-20 RPA5601 - Jun 20, 16:39 UTCJun 20, 18:14 UTC1h 35m
2026-06-20 RPA5601 - Jun 20, 13:44 UTCJun 20, 15:49 UTC2h 5m
2026-06-20 RPA5751 LGA → BNH Jun 20, 02:40 UTCJun 20, 03:19 UTC40m
2026-06-19 RPA5843 - Jun 19, 23:49 UTCJun 20, 00:59 UTC1h 10m
2026-06-19 RPA5843 - Jun 19, 20:59 UTCJun 19, 22:09 UTC1h 10m
2026-06-19 RPA5730 BOS → LGA Jun 19, 18:44 UTCJun 19, 19:25 UTC40m
2026-06-19 RPA5730 BOS → LGA Jun 19, 18:36 UTCJun 19, 19:25 UTC49m
2026-06-19 RPA5622 - Jun 19, 16:34 UTCJun 19, 17:34 UTC1h 0m
2026-06-19 RPA5622 RIC → BOS Jun 19, 16:29 UTCJun 19, 17:36 UTC1h 7m
2026-06-19 RPA5622 - Jun 19, 13:54 UTCJun 19, 15:14 UTC1h 20m

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 N203JQ page for operator, model, and routing details .

Mode-S A19DFF frequently asked

What is Mode-S code A19DFF?
A19DFF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N203JQ.
Where is Mode-S A19DFF registered?
Mode-S code A19DFF 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 A19DFF broadcasting right now?
No active broadcast right now. Last signal was 17d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A19DFF, octal 50316777, decimal 10,591,743.
What flights does A19DFF operate?
Mode-S A19DFF has broadcast 20 distinct callsigns, including RPA5703, RPA5689, RPA5675, RPA5829, RPA5758.