sensors Mode-S transponder

A858F6

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N637NN · operated by AMERICAN AIRLINES INC

Hex
A858F6
Octal
52054366
Decimal
11,032,822
Country
US
Tail
N637NN
Type
CRJ9
Broadcasting now · callsign JIA5128 · 34,000 ft
Flights observed
11
Distinct callsigns
8
Country
US
Last broadcast
14h ago

Current position

A858F6 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A858F6 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 8 distinct

Callsign Airline Flights Last seen
JIA5183 PSA Airlines 3 2026-04-13
JIA5267 - 2 2026-04-13
JIA5625 - 1 2026-04-13
JIA5500 - 1 2026-04-13
JIA5461 - 1 2026-04-12
JIA5382 - 1 2026-04-13
JIA5268 - 1 2026-04-13
JIA5149 PSA Airlines 1 2026-04-14

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-14 JIA5149 TYS → DCA Apr 14, 10:05 UTCApr 14, 11:05 UTC1h 0m
2026-04-13 JIA5625 - Apr 13, 22:27 UTCApr 13, 23:21 UTC54m
2026-04-13 JIA5267 - Apr 13, 19:50 UTCApr 13, 20:30 UTC40m
2026-04-13 JIA5267 - Apr 13, 19:40 UTCApr 13, 20:10 UTC30m
2026-04-13 JIA5268 - Apr 13, 17:30 UTCApr 13, 18:28 UTC58m
2026-04-13 JIA5183 IND → DCA Apr 13, 15:50 UTCApr 13, 16:05 UTC15m
2026-04-13 JIA5183 IND → DCA Apr 13, 15:21 UTCApr 13, 16:01 UTC40m
2026-04-13 JIA5183 IND → DCA Apr 13, 13:31 UTCApr 13, 14:30 UTC59m
2026-04-13 JIA5500 - Apr 13, 11:07 UTCApr 13, 11:51 UTC44m
2026-04-13 JIA5382 - Apr 13, 00:40 UTCApr 13, 01:15 UTC35m
2026-04-12 JIA5461 - Apr 12, 18:20 UTCApr 12, 19:40 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 N637NN page for operator, model, and routing details .

Mode-S A858F6 frequently asked

What is Mode-S code A858F6?
A858F6 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N637NN.
Where is Mode-S A858F6 registered?
Mode-S code A858F6 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 A858F6 broadcasting right now?
Yes. Mode-S A858F6 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A858F6, octal 52054366, decimal 11,032,822.
What flights does A858F6 operate?
Mode-S A858F6 has broadcast 8 distinct callsigns, including JIA5183, JIA5267, JIA5625, JIA5500, JIA5461.