Apparatus

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sensors Mode-S transponder

A9F87D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N741YX · EMBRAER ERJ-170-200 (long wing) · operated by UNITED AIRLINES INC

Hex
A9F87D
Octal
52374175
Decimal
11,139,197
Country
US
Tail
N741YX
Type
E75L
Broadcasting now · callsign RPA3405 · 15,875 ft
Flights observed
632
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:15 UTC

Current position

A9F87D is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A9F87D 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
RPA3422 - 9 2026-07-11
RPA3702 Republic Airlines 8 2026-06-13
RPA3533 - 8 2026-07-16
RPA3450 - 8 2026-07-16
RPA3659 Republic Airlines 7 2026-07-25
RPA3621 Republic Airlines 7 2026-07-24
RPA3680 - 6 2026-06-30
RPA3614 Republic Airlines 6 2026-07-20
RPA3580 - 6 2026-07-16
RPA3549 - 6 2026-07-09
RPA3715 - 5 2026-07-09
RPA3708 - 5 2026-07-07
RPA3707 - 5 2026-07-15
RPA3686 - 5 2026-07-04
RPA3661 - 5 2026-06-27
RPA3658 Republic Airlines 5 2026-07-22
RPA3657 Republic Airlines 5 2026-07-25
RPA3604 - 5 2026-06-18
RPA3598 Republic Airlines 5 2026-06-27
RPA3594 - 5 2026-07-07

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 RPA3436 CLT → EWR Jul 26, 19:15 UTCJul 26, 21:15 UTC2h 0m
2026-07-26 RPA3448 EWR → EYW Jul 26, 15:35 UTCJul 26, 16:50 UTC1h 15m
2026-07-26 RPA3517 EWR → YYZ Jul 26, 12:00 UTCJul 26, 13:25 UTC1h 25m
2026-07-26 RPA3655 EWR → SDF Jul 26, 01:25 UTCJul 26, 02:20 UTC55m
2026-07-25 RPA3651 EWR → CVG Jul 25, 21:55 UTCJul 25, 23:05 UTC1h 10m
2026-07-25 RPA3401 BNA → EWR Jul 25, 18:55 UTCJul 25, 20:00 UTC1h 5m
2026-07-25 RPA3401 BNA → EWR Jul 25, 19:03 UTCJul 25, 19:59 UTC56m
2026-07-25 RPA3646 MEM → EWR Jul 25, 16:05 UTCJul 25, 17:40 UTC1h 35m
2026-07-25 RPA3696 EWR → CLT Jul 25, 13:10 UTCJul 25, 14:05 UTC55m
2026-07-25 RPA3696 EWR → CLT Jul 25, 13:17 UTCJul 25, 13:57 UTC40m
2026-07-25 RPA3659 GSO → EWR Jul 25, 03:00 UTCJul 25, 03:55 UTC55m
2026-07-25 RPA3659 GSO → EWR Jul 25, 02:58 UTCJul 25, 03:53 UTC55m
2026-07-25 RPA3657 SAV → EWR Jul 25, 00:20 UTCJul 25, 01:05 UTC45m
2026-07-24 RPA3585 IND → EWR Jul 24, 21:46 UTCJul 24, 23:11 UTC1h 25m
2026-07-24 RPA3414 EWR → BNA Jul 24, 18:45 UTCJul 24, 20:00 UTC1h 15m
2026-07-24 RPA3621 IAD → EWR Jul 24, 16:45 UTCJul 24, 17:45 UTC1h 0m
2026-07-24 RPA3621 IAD → EWR Jul 24, 16:52 UTCJul 24, 17:41 UTC49m
2026-07-24 RPA3560 - Jul 24, 13:25 UTCJul 24, 14:25 UTC1h 0m
2026-07-23 RPA3447 IAD → JAX Jul 23, 22:50 UTCJul 23, 23:45 UTC55m
2026-07-23 RPA3471 EWR → GSO Jul 23, 18:20 UTCJul 23, 20:10 UTC1h 50m
2026-07-23 RPA3471 EWR → GSO Jul 23, 18:04 UTCJul 23, 20:00 UTC1h 56m
2026-07-23 RPA3513 EWR → BTV Jul 23, 15:40 UTCJul 23, 16:50 UTC1h 10m
2026-07-23 RPA3560 - Jul 23, 13:30 UTCJul 23, 14:20 UTC50m
2026-07-23 RPA3464 BUF → EWR Jul 23, 02:45 UTCJul 23, 03:45 UTC1h 0m
2026-07-22 RPA3597 SRQ → EWR Jul 22, 22:40 UTCJul 23, 00:35 UTC1h 55m
2026-07-22 RPA3658 GRR → EWR Jul 22, 19:40 UTCJul 22, 21:30 UTC1h 50m
2026-07-22 RPA3617 EWR → PVD Jul 22, 15:55 UTCJul 22, 16:05 UTC10m
2026-07-22 RPA3617 EWR → PVD Jul 22, 14:40 UTCJul 22, 16:05 UTC1h 25m
2026-07-22 RPA3617 EWR → PVD Jul 22, 14:35 UTCJul 22, 15:36 UTC1h 1m
2026-07-21 RPA3431 BUF → EWR Jul 21, 12:55 UTCJul 21, 13:55 UTC1h 0m
2026-07-21 RPA3693 IAD → BTV Jul 21, 10:25 UTCJul 21, 11:00 UTC35m
2026-07-21 RPA3502 IAD → PHL Jul 21, 02:30 UTCJul 21, 03:05 UTC35m
2026-07-21 RPA3445 EWR → MKE Jul 21, 00:15 UTCJul 21, 01:25 UTC1h 10m
2026-07-20 RPA3418 - Jul 20, 22:40 UTCJul 20, 23:15 UTC35m
2026-07-20 RPA3427 - Jul 20, 19:25 UTCJul 20, 20:10 UTC45m
2026-07-20 RPA3446 CLT → EWR Jul 20, 16:16 UTCJul 20, 17:46 UTC1h 30m
2026-07-20 RPA3446 CLT → EWR Jul 20, 16:15 UTCJul 20, 17:15 UTC1h 0m
2026-07-20 RPA3467 CMH → EWR Jul 20, 13:20 UTCJul 20, 14:35 UTC1h 15m
2026-07-20 RPA3614 STL → EWR Jul 20, 01:55 UTCJul 20, 02:25 UTC30m
2026-07-20 RPA3614 STL → EWR Jul 20, 01:40 UTCJul 20, 02:25 UTC45m
2026-07-19 RPA3659 GSO → EWR Jul 19, 22:40 UTCJul 20, 00:20 UTC1h 40m
2026-07-19 RPA3452 - Jul 19, 20:00 UTCJul 19, 21:10 UTC1h 10m
2026-07-19 RPA3452 EWR → YOW Jul 19, 19:55 UTCJul 19, 20:59 UTC1h 4m
2026-07-19 RPA3697 - Jul 19, 15:40 UTCJul 19, 16:45 UTC1h 5m
2026-07-19 RPA3509 EWR → BNA Jul 19, 02:31 UTCJul 19, 03:51 UTC1h 20m
2026-07-19 RPA3509 EWR → BNA Jul 19, 02:30 UTCJul 19, 03:15 UTC45m
2026-07-19 RPA3485 - Jul 19, 00:00 UTCJul 19, 01:00 UTC1h 0m
2026-07-18 RPA3485 CVG → ORD Jul 18, 23:35 UTCJul 19, 00:46 UTC1h 11m
2026-07-18 RPA3321 PVD → MSN Jul 18, 21:35 UTCJul 18, 22:20 UTC45m
2026-07-18 RPA3321 PVD → MSN Jul 18, 21:31 UTCJul 18, 22:24 UTC53m

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 N741YX page for operator, model, and routing details .

Mode-S A9F87D frequently asked

What is Mode-S code A9F87D?
A9F87D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N741YX.
Where is Mode-S A9F87D registered?
Mode-S code A9F87D 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 A9F87D broadcasting right now?
Yes. Mode-S A9F87D is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A9F87D, octal 52374175, decimal 11,139,197.
What flights does A9F87D operate?
Mode-S A9F87D has broadcast 20 distinct callsigns, including RPA3422, RPA3702, RPA3533, RPA3450, RPA3659.