sensors Mode-S transponder

AC142E

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N878BG · BOEING 787-8 Dreamliner · operated by WILMINGTON TRUST CO TRUSTEE

Hex
AC142E
Octal
53012056
Decimal
11,277,358
Country
US
Tail
N878BG
Type
B788
Broadcasting now · callsign AAL957 · 41,000 ft
Flights observed
6
Distinct callsigns
2
Country
US
Last broadcast
22h ago

Current position

AC142E is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address AC142E 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
AAL957 - 4 2026-04-13
AAL912 American Airlines 2 2026-04-14

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-14 AAL912 SCL → MIA Apr 14, 08:05 UTCApr 14, 08:35 UTC30m
2026-04-14 AAL912 SCL → MIA Apr 14, 06:45 UTCApr 14, 07:05 UTC20m
2026-04-13 AAL957 - Apr 13, 08:20 UTCApr 13, 08:50 UTC30m
2026-04-13 AAL957 - Apr 13, 08:05 UTCApr 13, 08:50 UTC45m
2026-04-13 AAL957 - Apr 13, 04:20 UTCApr 13, 08:15 UTC3h 55m
2026-04-13 AAL957 - Apr 13, 04:03 UTCApr 13, 11:35 UTC7h 32m

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 N878BG page for operator, model, and routing details .

Mode-S AC142E frequently asked

What is Mode-S code AC142E?
AC142E is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N878BG.
Where is Mode-S AC142E registered?
Mode-S code AC142E 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 AC142E broadcasting right now?
Yes. Mode-S AC142E is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC142E, octal 53012056, decimal 11,277,358.
What flights does AC142E operate?
Mode-S AC142E has broadcast 2 distinct callsigns, including AAL957, AAL912.