sensors Mode-S transponder

A7A257

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N591NN · BOMBARDIER Regional Jet CRJ-900 · operated by AMERICAN AIRLINES INC

Hex
A7A257
Octal
51721127
Decimal
10,986,071
Country
US
Tail
N591NN
Type
CRJ9
No current signal · last broadcast 1d ago
Flights observed
14
Distinct callsigns
4
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A7A257.

Country allocation

The ICAO 24-bit address A7A257 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 4 distinct

Callsign Airline Flights Last seen
JIA5324 - 7 2026-04-13
JIA5079 - 4 2026-04-13
JIA5199 PSA Airlines 2 2026-04-13
JIA5273 PSA Airlines 1 2026-04-13

Recent flights last 14

DateFlightRouteTakeoffLandingDuration
2026-04-13 JIA5273 PHL → DAY Apr 13, 22:20 UTCApr 13, 23:45 UTC1h 25m
2026-04-13 JIA5324 - Apr 13, 19:45 UTCApr 13, 19:55 UTC10m
2026-04-13 JIA5324 - Apr 13, 18:16 UTCApr 13, 20:21 UTC2h 5m
2026-04-13 JIA5324 - Apr 13, 18:01 UTCApr 13, 19:53 UTC1h 52m
2026-04-13 JIA5324 - Apr 13, 16:15 UTCApr 13, 17:05 UTC50m
2026-04-13 JIA5324 - Apr 13, 15:50 UTCApr 13, 17:05 UTC1h 15m
2026-04-13 JIA5324 - Apr 13, 15:02 UTCApr 13, 17:22 UTC2h 20m
2026-04-13 JIA5079 - Apr 13, 12:20 UTCApr 13, 13:10 UTC50m
2026-04-13 JIA5079 - Apr 13, 11:55 UTCApr 13, 13:10 UTC1h 15m
2026-04-13 JIA5079 - Apr 13, 11:39 UTCApr 13, 13:28 UTC1h 49m
2026-04-13 JIA5079 - Apr 13, 11:39 UTCApr 13, 13:28 UTC1h 49m
2026-04-13 JIA5199 PIT → PHL Apr 13, 04:20 UTCApr 13, 06:00 UTC1h 40m
2026-04-13 JIA5199 PIT → PHL Apr 13, 04:10 UTCApr 13, 06:00 UTC1h 50m
2026-04-12 JIA5324 - Apr 12, 19:10 UTCApr 12, 20:15 UTC1h 5m

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 N591NN page for operator, model, and routing details .

Mode-S A7A257 frequently asked

What is Mode-S code A7A257?
A7A257 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N591NN.
Where is Mode-S A7A257 registered?
Mode-S code A7A257 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 A7A257 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A7A257, octal 51721127, decimal 10,986,071.
What flights does A7A257 operate?
Mode-S A7A257 has broadcast 4 distinct callsigns, including JIA5324, JIA5079, JIA5199, JIA5273.