Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A90821

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N681NG · PILATUS PC-12 · operated by EXA LLC

Hex
A90821
Octal
52204041
Decimal
11,077,665
Country
US
Tail
N681NG
Type
PC12
No current signal · last broadcast 3d ago
Flights observed
101
Distinct callsigns
2
Country
US
Last broadcast
3d ago

Last known position

Most recent position reported by Mode-S A90821.

Country allocation

The ICAO 24-bit address A90821 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
TEK681 - 100 2026-07-17
N681NG - 1 2026-04-30

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-17 TEK681 - Jul 17, 15:49 UTCJul 17, 17:40 UTC1h 50m
2026-07-17 TEK681 - Jul 17, 12:55 UTCJul 17, 15:10 UTC2h 15m
2026-07-16 TEK681 - Jul 16, 19:10 UTCJul 16, 20:05 UTC55m
2026-07-16 TEK681 - Jul 16, 15:45 UTCJul 16, 16:30 UTC45m
2026-07-11 TEK681 LNS → LNS Jul 11, 12:55 UTCJul 11, 17:40 UTC4h 45m
2026-07-10 TEK681 - Jul 10, 00:35 UTCJul 10, 02:30 UTC1h 55m
2026-07-09 TEK681 - Jul 9, 20:30 UTCJul 9, 22:45 UTC2h 15m
2026-07-09 TEK681 - Jul 9, 17:55 UTCJul 9, 19:10 UTC1h 15m
2026-07-09 TEK681 - Jul 9, 15:55 UTCJul 9, 17:05 UTC1h 10m
2026-07-06 TEK681 - Jul 6, 21:55 UTCJul 6, 23:50 UTC1h 55m
2026-07-06 TEK681 - Jul 6, 19:10 UTCJul 6, 21:20 UTC2h 10m
2026-07-05 TEK681 - Jul 5, 18:00 UTCJul 5, 20:00 UTC2h 0m
2026-07-05 TEK681 - Jul 5, 15:15 UTCJul 5, 17:25 UTC2h 10m
2026-07-01 TEK681 - Jul 1, 16:00 UTCJul 1, 18:00 UTC2h 0m
2026-07-01 TEK681 - Jul 1, 13:00 UTCJul 1, 15:15 UTC2h 15m
2026-06-25 TEK681 - Jun 25, 22:10 UTCJun 25, 23:44 UTC1h 35m
2026-06-25 TEK681 - Jun 25, 18:59 UTCJun 25, 21:05 UTC2h 5m
2026-06-24 TEK681 - Jun 24, 23:40 UTCJun 25, 00:55 UTC1h 15m
2026-06-24 TEK681 - Jun 24, 21:14 UTCJun 24, 23:04 UTC1h 50m
2026-06-23 TEK681 - Jun 23, 16:09 UTCJun 23, 18:20 UTC2h 10m
2026-06-23 TEK681 LNS → OSU Jun 23, 14:04 UTCJun 23, 15:30 UTC1h 25m
2026-06-22 TEK681 - Jun 22, 12:15 UTCJun 22, 13:29 UTC1h 15m
2026-06-22 TEK681 - Jun 22, 10:10 UTCJun 22, 11:44 UTC1h 35m
2026-06-21 TEK681 BTV → LNS Jun 21, 15:15 UTCJun 21, 16:34 UTC1h 20m
2026-06-21 TEK681 - Jun 21, 13:54 UTCJun 21, 14:40 UTC45m
2026-06-21 TEK681 - Jun 21, 11:05 UTCJun 21, 13:04 UTC2h 0m
2026-06-17 TEK681 ALB → LNS Jun 17, 20:50 UTCJun 17, 21:50 UTC1h 0m
2026-06-17 TEK681 - Jun 17, 18:40 UTCJun 17, 19:55 UTC1h 15m
2026-06-17 TEK681 LNS → YQB Jun 17, 15:46 UTCJun 17, 17:45 UTC2h 0m
2026-06-14 TEK681 - Jun 14, 18:55 UTCJun 14, 20:10 UTC1h 15m
2026-06-14 TEK681 - Jun 14, 17:35 UTCJun 14, 18:25 UTC50m
2026-06-14 TEK681 - Jun 14, 15:55 UTCJun 14, 16:25 UTC30m
2026-06-14 TEK681 - Jun 14, 14:45 UTCJun 14, 15:15 UTC30m
2026-06-14 TEK681 - Jun 14, 13:25 UTCJun 14, 14:10 UTC45m
2026-06-09 TEK681 - Jun 9, 21:40 UTCJun 9, 22:10 UTC30m
2026-06-09 TEK681 - Jun 9, 19:50 UTCJun 9, 20:45 UTC55m
2026-06-08 TEK681 - Jun 8, 15:55 UTCJun 8, 16:50 UTC55m
2026-06-08 TEK681 - Jun 8, 14:10 UTCJun 8, 14:40 UTC30m
2026-06-08 TEK681 LNS → BBX Jun 8, 12:30 UTCJun 8, 12:45 UTC15m
2026-06-07 TEK681 IAD → LNS Jun 7, 21:10 UTCJun 7, 21:40 UTC30m
2026-06-07 TEK681 - Jun 7, 18:20 UTCJun 7, 20:15 UTC1h 55m
2026-06-07 TEK681 LNS → HTO Jun 7, 16:20 UTCJun 7, 17:10 UTC50m
2026-06-05 TEK681 - Jun 5, 20:05 UTCJun 5, 20:20 UTC15m
2026-06-05 TEK681 BED → ILG Jun 5, 18:15 UTCJun 5, 19:30 UTC1h 15m
2026-06-05 TEK681 IAD → BED Jun 5, 14:30 UTCJun 5, 16:40 UTC2h 10m
2026-06-05 TEK681 LNS → IAD Jun 5, 12:05 UTCJun 5, 12:35 UTC30m
2026-06-03 TEK681 - Jun 3, 20:05 UTCJun 3, 21:25 UTC1h 20m
2026-06-03 TEK681 - Jun 3, 10:10 UTCJun 3, 11:30 UTC1h 20m
2026-06-02 TEK681 - Jun 2, 16:50 UTCJun 2, 18:25 UTC1h 35m
2026-06-02 TEK681 - Jun 2, 14:40 UTCJun 2, 16:10 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 N681NG page for operator, model, and routing details .

Mode-S A90821 frequently asked

What is Mode-S code A90821?
A90821 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N681NG.
Where is Mode-S A90821 registered?
Mode-S code A90821 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 A90821 broadcasting right now?
No active broadcast right now. Last signal was 3d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A90821, octal 52204041, decimal 11,077,665.
What flights does A90821 operate?
Mode-S A90821 has broadcast 2 distinct callsigns, including TEK681, N681NG.