sensors Mode-S transponder

AA7F02

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N77572 · BOEING 737 MAX 9 · operated by UNITED AIRLINES INC

Hex
AA7F02
Octal
52477402
Decimal
11,173,634
Country
US
Tail
N77572
Type
B39M
No current signal · last broadcast 1d ago
Flights observed
8
Distinct callsigns
4
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S AA7F02.

Country allocation

The ICAO 24-bit address AA7F02 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 4 distinct

Callsign Airline Flights Last seen
UAL2861 - 4 2026-04-13
UAL2044 - 2 2026-04-13
UAL2217 United Airlines 1 2026-04-13
UAL1628 United Airlines 1 2026-04-12

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-13 UAL2217 ORD → PIT Apr 13, 22:45 UTCApr 13, 23:45 UTC1h 0m
2026-04-13 UAL2861 - Apr 13, 19:50 UTCApr 13, 20:00 UTC10m
2026-04-13 UAL2861 - Apr 13, 16:15 UTCApr 13, 20:00 UTC3h 45m
2026-04-13 UAL2861 - Apr 13, 15:50 UTCApr 13, 19:45 UTC3h 55m
2026-04-13 UAL2861 - Apr 13, 15:23 UTCApr 13, 19:54 UTC4h 31m
2026-04-13 UAL2044 - Apr 13, 04:55 UTCApr 13, 05:55 UTC1h 0m
2026-04-13 UAL2044 - Apr 13, 00:58 UTCApr 13, 05:47 UTC4h 49m
2026-04-12 UAL1628 MBJ → EWR Apr 12, 18:05 UTCApr 12, 21:19 UTC3h 14m

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 N77572 page for operator, model, and routing details .

Mode-S AA7F02 frequently asked

What is Mode-S code AA7F02?
AA7F02 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N77572.
Where is Mode-S AA7F02 registered?
Mode-S code AA7F02 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 AA7F02 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AA7F02, octal 52477402, decimal 11,173,634.
What flights does AA7F02 operate?
Mode-S AA7F02 has broadcast 4 distinct callsigns, including UAL2861, UAL2044, UAL2217, UAL1628.