Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

AA91B6

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N780ND · PIPER PA-44 Seminole · operated by UNIVERSITY OF NORTH DAKOTA, C/O JOHN D ODEGARD SCHOOL OF AEROSPACE SCIENCES

Hex
AA91B6
Octal
52510666
Decimal
11,178,422
Country
US
Tail
N780ND
Type
PA44
No current signal · last broadcast Jul 22, 21:30 UTC
Flights observed
119
Distinct callsigns
1
Country
US
Last broadcast
Jul 22, 21:30 UTC

Last known position

Most recent position reported by Mode-S AA91B6.

Country allocation

The ICAO 24-bit address AA91B6 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
NDU80T - 119 2026-07-22

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-22 NDU80T - Jul 22, 21:00 UTCJul 22, 21:30 UTC30m
2026-07-22 NDU80T - Jul 22, 19:00 UTCJul 22, 19:15 UTC15m
2026-07-22 NDU80T - Jul 22, 14:30 UTCJul 22, 15:00 UTC30m
2026-07-22 NDU80T - Jul 22, 03:25 UTCJul 22, 04:50 UTC1h 25m
2026-07-21 NDU80T - Jul 21, 12:30 UTCJul 21, 13:00 UTC30m
2026-07-20 NDU80T - Jul 20, 13:35 UTCJul 20, 13:45 UTC10m
2026-07-17 NDU80T - Jul 17, 15:10 UTCJul 17, 16:55 UTC1h 45m
2026-07-15 NDU80T - Jul 15, 21:35 UTCJul 15, 22:40 UTC1h 5m
2026-07-15 NDU80T - Jul 15, 18:10 UTCJul 15, 18:30 UTC20m
2026-07-11 NDU80T - Jul 11, 19:55 UTCJul 11, 20:25 UTC30m
2026-07-11 NDU80T - Jul 11, 16:50 UTCJul 11, 17:25 UTC35m
2026-07-09 NDU80T - Jul 9, 23:00 UTCJul 9, 23:35 UTC35m
2026-07-09 NDU80T - Jul 9, 21:05 UTCJul 9, 21:30 UTC25m
2026-07-08 NDU80T - Jul 8, 16:35 UTCJul 8, 17:10 UTC35m
2026-07-02 NDU80T - Jul 2, 15:25 UTCJul 2, 15:35 UTC10m
2026-07-01 NDU80T - Jul 1, 23:35 UTCJul 1, 23:50 UTC15m
2026-07-01 NDU80T - Jul 1, 19:50 UTCJul 1, 20:15 UTC25m
2026-07-01 NDU80T - Jul 1, 17:40 UTCJul 1, 18:00 UTC20m
2026-07-01 NDU80T - Jul 1, 12:55 UTCJul 1, 13:25 UTC30m
2026-06-26 NDU80T - Jun 26, 18:49 UTCJun 26, 19:04 UTC15m
2026-06-26 NDU80T - Jun 26, 13:15 UTCJun 26, 13:49 UTC35m
2026-06-25 NDU80T - Jun 25, 22:34 UTCJun 25, 22:49 UTC15m
2026-06-25 NDU80T - Jun 25, 16:05 UTCJun 25, 16:39 UTC35m
2026-06-25 NDU80T - Jun 25, 12:10 UTCJun 25, 12:50 UTC40m
2026-06-25 NDU80T - Jun 25, 03:40 UTCJun 25, 05:25 UTC1h 45m
2026-06-24 NDU80T - Jun 24, 23:04 UTCJun 25, 00:40 UTC1h 35m
2026-06-16 NDU80T - Jun 16, 13:40 UTCJun 16, 14:09 UTC30m
2026-06-15 NDU80T - Jun 15, 17:25 UTCJun 15, 17:34 UTC10m
2026-06-15 NDU80T - Jun 15, 13:00 UTCJun 15, 13:40 UTC40m
2026-06-12 NDU80T - Jun 12, 16:50 UTCJun 12, 17:15 UTC25m
2026-06-12 NDU80T - Jun 12, 15:40 UTCJun 12, 16:15 UTC35m
2026-06-12 NDU80T - Jun 12, 13:00 UTCJun 12, 13:10 UTC10m
2026-06-11 NDU80T - Jun 11, 12:30 UTCJun 11, 13:55 UTC1h 25m
2026-06-11 NDU80T - Jun 11, 03:35 UTCJun 11, 05:10 UTC1h 35m
2026-06-10 NDU80T - Jun 10, 18:25 UTCJun 10, 18:50 UTC25m
2026-06-10 NDU80T - Jun 10, 13:25 UTCJun 10, 14:15 UTC50m
2026-06-09 NDU80T - Jun 9, 12:55 UTCJun 9, 13:35 UTC40m
2026-06-08 NDU80T - Jun 8, 20:10 UTCJun 8, 20:40 UTC30m
2026-06-06 NDU80T - Jun 6, 19:44 UTCJun 6, 20:14 UTC30m
2026-06-06 NDU80T - Jun 6, 18:25 UTCJun 6, 19:04 UTC40m
2026-06-06 NDU80T - Jun 6, 15:44 UTCJun 6, 16:34 UTC50m
2026-06-05 NDU80T - Jun 5, 19:35 UTCJun 5, 19:55 UTC20m
2026-06-05 NDU80T - Jun 5, 13:25 UTCJun 5, 13:35 UTC10m
2026-06-05 NDU80T - Jun 5, 05:05 UTCJun 5, 05:30 UTC25m
2026-06-05 NDU80T - Jun 5, 03:55 UTCJun 5, 04:25 UTC30m
2026-06-04 NDU80T - Jun 4, 22:20 UTCJun 4, 22:55 UTC35m
2026-06-04 NDU80T - Jun 4, 15:30 UTCJun 4, 15:40 UTC10m
2026-06-03 NDU80T - Jun 3, 16:35 UTCJun 3, 16:55 UTC20m
2026-06-02 NDU80T - Jun 2, 20:55 UTCJun 2, 22:20 UTC1h 25m
2026-06-02 NDU80T - Jun 2, 18:35 UTCJun 2, 18:45 UTC10m

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 N780ND page for operator, model, and routing details .

Mode-S AA91B6 frequently asked

What is Mode-S code AA91B6?
AA91B6 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N780ND.
Where is Mode-S AA91B6 registered?
Mode-S code AA91B6 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 AA91B6 broadcasting right now?
No active broadcast right now. Last signal was Jul 22, 21:30 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AA91B6, octal 52510666, decimal 11,178,422.
What flights does AA91B6 operate?
Mode-S AA91B6 has broadcast 1 distinct callsign, including NDU80T.