sensors Mode-S transponder

A891B7

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N651PA · CESSNA 172 Skyhawk · operated by SMN INVESTMENTS INC

Hex
A891B7
Octal
52110667
Decimal
11,047,351
Country
US
Tail
N651PA
Type
C172
No current signal · last broadcast 1d ago
Flights observed
6
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A891B7.

Country allocation

The ICAO 24-bit address A891B7 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 1 distinct

Callsign Airline Flights Last seen
N651PA - 6 2026-04-13

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-13 N651PA - Apr 13, 22:35 UTCApr 13, 23:40 UTC1h 5m
2026-04-13 N651PA LAF → LAF Apr 13, 20:30 UTCApr 13, 22:25 UTC1h 55m
2026-04-13 N651PA LAF → LAF Apr 13, 17:00 UTCApr 13, 18:45 UTC1h 45m
2026-04-13 N651PA LAF → LAF Apr 13, 14:15 UTCApr 13, 15:50 UTC1h 35m
2026-04-13 N651PA LAF → LAF Apr 13, 12:35 UTCApr 13, 13:30 UTC55m
2026-04-12 N651PA - Apr 12, 19:30 UTCApr 12, 20:15 UTC45m

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 N651PA page for operator, model, and routing details .

Mode-S A891B7 frequently asked

What is Mode-S code A891B7?
A891B7 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N651PA.
Where is Mode-S A891B7 registered?
Mode-S code A891B7 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 A891B7 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 A891B7, octal 52110667, decimal 11,047,351.
What flights does A891B7 operate?
Mode-S A891B7 has broadcast 1 distinct callsign, including N651PA.