sensors Mode-S transponder

A87318

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N64321 · operated by UNITED AIRLINES INC

Hex
A87318
Octal
52071430
Decimal
11,039,512
Country
US
Tail
N64321
No current signal · last broadcast 5d ago
Flights observed
7
Distinct callsigns
3
Country
US
Last broadcast
5d ago

Last known position

Most recent position reported by Mode-S A87318.

Country allocation

The ICAO 24-bit address A87318 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 3 distinct

Callsign Airline Flights Last seen
UAL4214 United Airlines 4 2026-06-06
UAL4211 - 2 2026-06-13
UAL4207 United Airlines 1 2026-07-08

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-07-08 UAL4207 BFI → SEA Jul 8, 14:05 UTCJul 8, 15:55 UTC1h 50m
2026-06-13 UAL4211 - Jun 13, 15:35 UTCJun 13, 16:00 UTC25m
2026-06-13 UAL4211 MLB → TPA Jun 13, 15:08 UTCJun 13, 15:59 UTC51m
2026-06-06 UAL4214 TLS → NQY Jun 6, 14:54 UTCJun 6, 15:25 UTC30m
2026-06-03 UAL4214 TLS → NQY Jun 3, 11:00 UTCJun 3, 21:28 UTC10h 28m
2026-06-03 UAL4214 TLS → NQY Jun 3, 11:00 UTCJun 3, 21:35 UTC10h 35m
2026-06-03 UAL4214 TLS → NQY Jun 3, 11:30 UTCJun 3, 12:00 UTC30m

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 N64321 page for operator, model, and routing details .

Mode-S A87318 frequently asked

What is Mode-S code A87318?
A87318 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N64321.
Where is Mode-S A87318 registered?
Mode-S code A87318 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 A87318 broadcasting right now?
No active broadcast right now. Last signal was 5d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A87318, octal 52071430, decimal 11,039,512.
What flights does A87318 operate?
Mode-S A87318 has broadcast 3 distinct callsigns, including UAL4214, UAL4211, UAL4207.