sensors Mode-S transponder

AA127E

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N748YX · EMBRAER ERJ-170-200 (long wing) · operated by UNITED AIRLINES INC

Hex
AA127E
Octal
52411176
Decimal
11,145,854
Country
US
Tail
N748YX
Type
E75L
No current signal · last broadcast 23h ago
Flights observed
11
Distinct callsigns
5
Country
US
Last broadcast
23h ago

Last known position

Most recent position reported by Mode-S AA127E.

Country allocation

The ICAO 24-bit address AA127E 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 5 distinct

Callsign Airline Flights Last seen
RPA3618 - 4 2026-04-13
RPA3532 - 3 2026-04-13
RPA3488 - 2 2026-04-13
RPA3671 - 1 2026-04-13
RPA3573 - 1 2026-04-12

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-13 RPA3671 - Apr 13, 23:20 UTCApr 13, 23:45 UTC25m
2026-04-13 RPA3532 - Apr 13, 19:50 UTCApr 13, 20:45 UTC55m
2026-04-13 RPA3532 - Apr 13, 18:18 UTCApr 13, 21:35 UTC3h 17m
2026-04-13 RPA3532 - Apr 13, 18:18 UTCApr 13, 21:04 UTC2h 46m
2026-04-13 RPA3618 - Apr 13, 16:15 UTCApr 13, 17:05 UTC50m
2026-04-13 RPA3618 - Apr 13, 15:50 UTCApr 13, 17:05 UTC1h 15m
2026-04-13 RPA3618 - Apr 13, 15:34 UTCApr 13, 17:01 UTC1h 27m
2026-04-13 RPA3618 - Apr 13, 12:21 UTCApr 13, 13:56 UTC1h 35m
2026-04-13 RPA3488 - Apr 13, 00:20 UTCApr 13, 01:00 UTC40m
2026-04-12 RPA3488 - Apr 12, 23:55 UTCApr 13, 01:00 UTC1h 5m
2026-04-12 RPA3573 - Apr 12, 17:15 UTCApr 12, 18:45 UTC1h 30m

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 N748YX page for operator, model, and routing details .

Mode-S AA127E frequently asked

What is Mode-S code AA127E?
AA127E is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N748YX.
Where is Mode-S AA127E registered?
Mode-S code AA127E 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 AA127E broadcasting right now?
No active broadcast right now. Last signal was 23h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AA127E, octal 52411176, decimal 11,145,854.
What flights does AA127E operate?
Mode-S AA127E has broadcast 5 distinct callsigns, including RPA3618, RPA3532, RPA3488, RPA3671, RPA3573.