sensors Mode-S transponder

A2615E

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N25201 · BOEING 737-800 · operated by UNITED AIRLINES INC

Hex
A2615E
Octal
50460536
Decimal
10,641,758
Country
US
Tail
N25201
Type
B738
No current signal · last broadcast 19h ago
Flights observed
11
Distinct callsigns
6
Country
US
Last broadcast
19h ago

Last known position

Most recent position reported by Mode-S A2615E.

Country allocation

The ICAO 24-bit address A2615E 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 6 distinct

Callsign Airline Flights Last seen
UAL1883 United Airlines 3 2026-04-13
UAL1156 United Airlines 3 2026-04-13
UAL2189 United Airlines 2 2026-04-13
UAL2299 - 1 2026-04-13
UAL2287 - 1 2026-04-12
UAL1710 - 1 2026-04-14

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-14 UAL1710 - Apr 14, 05:15 UTCApr 14, 05:35 UTC20m
2026-04-13 UAL2299 - Apr 13, 21:35 UTCApr 13, 23:35 UTC2h 0m
2026-04-13 UAL2189 MSY → ORD Apr 13, 19:50 UTCApr 13, 20:45 UTC55m
2026-04-13 UAL2189 MSY → ORD Apr 13, 18:19 UTCApr 13, 20:04 UTC1h 45m
2026-04-13 UAL1883 SFO → SJD Apr 13, 16:15 UTCApr 13, 17:20 UTC1h 5m
2026-04-13 UAL1883 SFO → SJD Apr 13, 15:50 UTCApr 13, 17:20 UTC1h 30m
2026-04-13 UAL1883 SFO → SJD Apr 13, 14:05 UTCApr 13, 16:15 UTC2h 10m
2026-04-13 UAL1156 IAD → EWR Apr 13, 04:20 UTCApr 13, 05:00 UTC40m
2026-04-13 UAL1156 IAD → EWR Apr 13, 03:55 UTCApr 13, 05:00 UTC1h 5m
2026-04-13 UAL1156 IAD → EWR Apr 13, 01:25 UTCApr 13, 04:15 UTC2h 50m
2026-04-12 UAL2287 - Apr 12, 17:15 UTCApr 12, 18:50 UTC1h 35m

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 N25201 page for operator, model, and routing details .

Mode-S A2615E frequently asked

What is Mode-S code A2615E?
A2615E is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N25201.
Where is Mode-S A2615E registered?
Mode-S code A2615E 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 A2615E broadcasting right now?
No active broadcast right now. Last signal was 19h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A2615E, octal 50460536, decimal 10,641,758.
What flights does A2615E operate?
Mode-S A2615E has broadcast 6 distinct callsigns, including UAL1883, UAL1156, UAL2189, UAL2299, UAL2287.