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sensors Mode-S transponder

A645B4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N503GJ · BOMBARDIER Regional Jet CRJ-700 · operated by BANK OF UTAH TRUSTEE

Hex
A645B4
Octal
51442664
Decimal
10,896,820
Country
US
Tail
N503GJ
Type
CRJ7
No current signal · last broadcast Jul 26, 21:25 UTC
Flights observed
700
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:25 UTC

Last known position

Most recent position reported by Mode-S A645B4.

Country allocation

The ICAO 24-bit address A645B4 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
GJS4482 - 14 2026-06-24
GJS4190 - 12 2026-06-24
GJS4480 GoJet Airlines 10 2026-06-16
GJS4439 - 10 2026-06-23
GJS4472 - 9 2026-07-10
GJS4400 GoJet Airlines 9 2026-07-24
GJS4188 - 9 2026-07-20
GJS4176 - 9 2026-07-10
GJS4582 GoJet Airlines 8 2026-06-20
GJS4603 - 7 2026-07-12
GJS4495 GoJet Airlines 7 2026-06-10
GJS4430 - 7 2026-07-17
GJS4429 - 7 2026-06-20
GJS4428 - 7 2026-07-20
GJS4191 GoJet Airlines 7 2026-06-07
GJS4604 - 6 2026-07-16
GJS4591 GoJet Airlines 6 2026-07-23
GJS4565 GoJet Airlines 6 2026-07-24
GJS4498 GoJet Airlines 6 2026-05-15
GJS4442 - 6 2026-07-17

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 GJS4441 GSO → EWR Jul 26, 20:15 UTCJul 26, 21:25 UTC1h 10m
2026-07-26 GJS4443 ILM → EWR Jul 26, 18:10 UTCJul 26, 19:20 UTC1h 10m
2026-07-26 GJS4584 IAD → EWR Jul 26, 14:35 UTCJul 26, 15:50 UTC1h 15m
2026-07-26 GJS4584 IAD → EWR Jul 26, 14:33 UTCJul 26, 15:36 UTC1h 3m
2026-07-26 GJS4551 ORD → XNA Jul 26, 12:25 UTCJul 26, 13:25 UTC1h 0m
2026-07-26 GJS4415 EWR → PHL Jul 26, 10:05 UTCJul 26, 11:00 UTC55m
2026-07-26 GJS4415 EWR → PHL Jul 26, 10:13 UTCJul 26, 11:03 UTC50m
2026-07-26 GJS4484 EWR → HHH Jul 26, 00:00 UTCJul 26, 00:40 UTC40m
2026-07-25 GJS4182 EWR → STL Jul 25, 20:55 UTCJul 25, 21:55 UTC1h 0m
2026-07-25 GJS4509 EWR → GSO Jul 25, 18:15 UTCJul 25, 19:05 UTC50m
2026-07-25 GJS4583 ORD → OMA Jul 25, 15:55 UTCJul 25, 16:30 UTC35m
2026-07-25 GJS4592 EWR → RIC Jul 25, 11:05 UTCJul 25, 11:40 UTC35m
2026-07-24 GJS4400 IAD → LGA Jul 24, 21:45 UTCJul 24, 23:25 UTC1h 40m
2026-07-24 GJS4523 ORD → RIC Jul 24, 19:25 UTCJul 24, 20:50 UTC1h 25m
2026-07-24 GJS4523 ORD → RIC Jul 24, 19:31 UTCJul 24, 20:50 UTC1h 19m
2026-07-24 GJS4525 EWR → PVD Jul 24, 16:25 UTCJul 24, 17:35 UTC1h 10m
2026-07-24 GJS4525 EWR → PVD Jul 24, 16:35 UTCJul 24, 17:14 UTC39m
2026-07-24 GJS4529 - Jul 24, 14:10 UTCJul 24, 15:15 UTC1h 5m
2026-07-24 GJS4565 ORD → ROC Jul 24, 11:05 UTCJul 24, 12:30 UTC1h 25m
2026-07-24 GJS4565 ORD → ROC Jul 24, 11:18 UTCJul 24, 12:22 UTC1h 4m
2026-07-23 GJS4591 DCA → EWR Jul 23, 20:55 UTCJul 23, 22:15 UTC1h 20m
2026-07-23 GJT4404 - Jul 23, 18:20 UTCJul 23, 19:15 UTC55m
2026-07-23 GJS4502 - Jul 23, 16:00 UTCJul 23, 16:50 UTC50m
2026-07-23 GJS4557 ORD → MSN Jul 23, 14:00 UTCJul 23, 14:45 UTC45m
2026-07-22 GJS4179 IAD → EWR Jul 22, 23:25 UTCJul 23, 00:00 UTC35m
2026-07-22 GJS4466 - Jul 22, 20:25 UTCJul 22, 21:30 UTC1h 5m
2026-07-22 GJS4466 SGF → ORD Jul 22, 20:23 UTCJul 22, 21:13 UTC50m
2026-07-22 GJS4569 - Jul 22, 17:40 UTCJul 22, 18:50 UTC1h 10m
2026-07-22 GJS4579 - Jul 22, 13:50 UTCJul 22, 15:15 UTC1h 25m
2026-07-21 GJS4425 IAD → STL Jul 21, 13:20 UTCJul 21, 15:05 UTC1h 45m
2026-07-21 GJS4503 EWR → DCA Jul 21, 10:40 UTCJul 21, 11:10 UTC30m
2026-07-21 GJS4503 EWR → DCA Jul 21, 10:47 UTCJul 21, 11:07 UTC20m
2026-07-20 GJS4393 - Jul 20, 22:10 UTCJul 20, 22:35 UTC25m
2026-07-20 GJS4418 ROA → IAD Jul 20, 18:50 UTCJul 20, 19:30 UTC40m
2026-07-20 GJS4612 IAD → ROA Jul 20, 17:20 UTCJul 20, 17:55 UTC35m
2026-07-20 GJS4181 DAY → IAD Jul 20, 14:35 UTCJul 20, 15:45 UTC1h 10m
2026-07-20 GJS4188 IAD → DAY Jul 20, 12:40 UTCJul 20, 13:45 UTC1h 5m
2026-07-20 GJS4428 CMH → IAD Jul 20, 10:35 UTCJul 20, 11:30 UTC55m
2026-07-20 GJS4414 IAD → CMH Jul 20, 02:45 UTCJul 20, 03:35 UTC50m
2026-07-20 GJS4593 EWR → STL Jul 20, 00:15 UTCJul 20, 01:05 UTC50m
2026-07-19 GJS4593 EWR → STL Jul 19, 23:58 UTCJul 20, 01:07 UTC1h 9m
2026-07-19 GJS4588 EWR → RIC Jul 19, 22:00 UTCJul 19, 22:55 UTC55m
2026-07-19 GJS4505 - Jul 19, 18:45 UTCJul 19, 19:35 UTC50m
2026-07-19 GJS4499 - Jul 19, 17:00 UTCJul 19, 17:40 UTC40m
2026-07-19 GJS4459 - Jul 19, 14:20 UTCJul 19, 15:35 UTC1h 15m
2026-07-19 GJS4459 YOW → IAD Jul 19, 14:16 UTCJul 19, 15:41 UTC1h 25m
2026-07-19 GJS4398 EWR → YOW Jul 19, 11:56 UTCJul 19, 12:53 UTC57m
2026-07-19 GJS4398 - Jul 19, 11:50 UTCJul 19, 12:50 UTC1h 0m
2026-07-18 GJS4526 ORF → IAD Jul 18, 02:09 UTCJul 18, 03:00 UTC51m
2026-07-17 GJS4552 EWR → BUF Jul 17, 20:55 UTCJul 17, 21:50 UTC55m

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 N503GJ page for operator, model, and routing details .

Mode-S A645B4 frequently asked

What is Mode-S code A645B4?
A645B4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N503GJ.
Where is Mode-S A645B4 registered?
Mode-S code A645B4 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 A645B4 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 21:25 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A645B4, octal 51442664, decimal 10,896,820.
What flights does A645B4 operate?
Mode-S A645B4 has broadcast 20 distinct callsigns, including GJS4482, GJS4190, GJS4480, GJS4439, GJS4472.