Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A11BC8

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N17017 · BOEING 787-10 Dreamliner · operated by UNITED AIRLINES INC

Hex
A11BC8
Octal
50215710
Decimal
10,558,408
Country
US
Tail
N17017
Type
B78X
No current signal · last broadcast 15h ago
Flights observed
12
Distinct callsigns
2
Country
US
Last broadcast
15h ago

Last known position

Most recent position reported by Mode-S A11BC8.

Country allocation

The ICAO 24-bit address A11BC8 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 2 distinct

Callsign Airline Flights Last seen
UAL986 - 7 2026-04-14
UAL987 United Airlines 5 2026-04-14

Recent flights last 12

DateFlightRouteTakeoffLandingDuration
2026-04-14 UAL986 - Apr 14, 10:00 UTCApr 14, 11:05 UTC1h 5m
2026-04-14 UAL987 ORD → CDG Apr 14, 07:10 UTCApr 14, 07:20 UTC10m
2026-04-14 UAL987 ORD → CDG Apr 14, 06:10 UTCApr 14, 07:10 UTC1h 0m
2026-04-13 UAL986 - Apr 13, 19:45 UTCApr 13, 19:50 UTC5m
2026-04-13 UAL986 - Apr 13, 18:00 UTCApr 13, 19:50 UTC1h 50m
2026-04-13 UAL986 - Apr 13, 12:20 UTCApr 13, 12:40 UTC20m
2026-04-13 UAL986 - Apr 13, 11:55 UTCApr 13, 12:40 UTC45m
2026-04-13 UAL986 - Apr 13, 11:09 UTCApr 13, 19:48 UTC8h 39m
2026-04-13 UAL986 - Apr 13, 11:09 UTCApr 13, 19:24 UTC8h 15m
2026-04-13 UAL987 ORD → CDG Apr 13, 05:35 UTCApr 13, 07:00 UTC1h 25m
2026-04-13 UAL987 ORD → CDG Apr 13, 00:20 UTCApr 13, 02:20 UTC2h 0m
2026-04-12 UAL987 ORD → CDG Apr 12, 23:55 UTCApr 13, 02:20 UTC2h 25m

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 N17017 page for operator, model, and routing details .

Mode-S A11BC8 frequently asked

What is Mode-S code A11BC8?
A11BC8 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N17017.
Where is Mode-S A11BC8 registered?
Mode-S code A11BC8 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 A11BC8 broadcasting right now?
No active broadcast right now. Last signal was 15h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A11BC8, octal 50215710, decimal 10,558,408.
What flights does A11BC8 operate?
Mode-S A11BC8 has broadcast 2 distinct callsigns, including UAL986, UAL987.