sensors Mode-S transponder

A1515B

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N184US · AIRBUS A-321 · operated by AMERICAN AIRLINES INC

Hex
A1515B
Octal
50250533
Decimal
10,572,123
Country
US
Tail
N184US
Type
A321
Broadcasting now · callsign AAL2104 · 0 ft
Flights observed
25
Distinct callsigns
11
Country
US
Last broadcast
59m ago

Current position

A1515B is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A1515B 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 11 distinct

Callsign Airline Flights Last seen
AAL2852 American Airlines 6 2026-04-17
AAL1177 American Airlines 4 2026-04-15
AAL2671 American Airlines 3 2026-04-16
AAL558 American Airlines 2 2026-04-15
AAL2531 American Airlines 2 2026-04-16
AAL2502 American Airlines 2 2026-04-17
AAL1670 American Airlines 2 2026-04-17
AAL9804 American Airlines 1 2026-04-15
AAL700 - 1 2026-04-18
AAL2209 American Airlines 1 2026-04-18
AAL2104 - 1 2026-04-18

Recent flights last 25

DateFlightRouteTakeoffLandingDuration
2026-04-18 AAL2104 - Apr 18, 15:20 UTCApr 18, 16:40 UTC1h 20m
2026-04-18 AAL700 - Apr 18, 13:05 UTCApr 18, 13:50 UTC45m
2026-04-18 AAL2209 DFW → IAH Apr 18, 02:30 UTCApr 18, 03:10 UTC40m
2026-04-17 AAL2852 DFW → MBJ Apr 17, 23:25 UTCApr 18, 00:25 UTC1h 0m
2026-04-17 AAL2852 DFW → MBJ Apr 17, 21:25 UTCApr 17, 23:20 UTC1h 55m
2026-04-17 AAL2852 DFW → MBJ Apr 17, 19:40 UTCApr 17, 19:55 UTC15m
2026-04-17 AAL2852 DFW → MBJ Apr 17, 18:00 UTCApr 17, 18:15 UTC15m
2026-04-17 AAL2852 DFW → MBJ Apr 17, 15:20 UTCApr 17, 16:30 UTC1h 10m
2026-04-17 AAL2852 DFW → MBJ Apr 17, 14:10 UTCApr 17, 15:15 UTC1h 4m
2026-04-17 AAL1670 PHL → DFW Apr 17, 11:20 UTCApr 17, 12:10 UTC50m
2026-04-17 AAL1670 PHL → DFW Apr 17, 09:20 UTCApr 17, 11:15 UTC1h 55m
2026-04-17 AAL2502 MCO → PHL Apr 17, 01:20 UTCApr 17, 02:55 UTC1h 35m
2026-04-17 AAL2502 MCO → PHL Apr 17, 00:55 UTCApr 17, 01:15 UTC20m
2026-04-16 AAL2531 PHL → MCO Apr 16, 21:14 UTCApr 16, 22:40 UTC1h 25m
2026-04-16 AAL2531 PHL → MCO Apr 16, 20:34 UTCApr 16, 22:34 UTC2h 0m
2026-04-16 AAL2671 CLT → VPS Apr 16, 17:15 UTCApr 16, 18:00 UTC45m
2026-04-16 AAL2671 CLT → VPS Apr 16, 15:15 UTCApr 16, 17:10 UTC1h 55m
2026-04-16 AAL2671 CLT → VPS Apr 16, 14:15 UTCApr 16, 15:10 UTC55m
2026-04-15 AAL558 DFW → EWR Apr 15, 23:10 UTCApr 16, 01:05 UTC1h 55m
2026-04-15 AAL558 DFW → EWR Apr 15, 22:40 UTCApr 15, 23:00 UTC20m
2026-04-15 AAL1177 ORD → PHL Apr 15, 19:05 UTCApr 15, 20:50 UTC1h 45m
2026-04-15 AAL1177 ORD → PHL Apr 15, 18:00 UTCApr 15, 19:00 UTC1h 0m
2026-04-15 AAL1177 ORD → PHL Apr 15, 15:05 UTCApr 15, 16:05 UTC1h 0m
2026-04-15 AAL1177 ORD → PHL Apr 15, 13:45 UTCApr 15, 14:55 UTC1h 9m
2026-04-15 AAL9804 ORD → TUL Apr 15, 00:55 UTCApr 15, 01:45 UTC50m

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 N184US page for operator, model, and routing details .

Mode-S A1515B frequently asked

What is Mode-S code A1515B?
A1515B is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N184US.
Where is Mode-S A1515B registered?
Mode-S code A1515B 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 A1515B broadcasting right now?
Yes. Mode-S A1515B is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A1515B, octal 50250533, decimal 10,572,123.
What flights does A1515B operate?
Mode-S A1515B has broadcast 11 distinct callsigns, including AAL2852, AAL1177, AAL2671, AAL558, AAL2531.