Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A91DFB

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N687HV · BEECH T-34 Mentor · operated by AMERICAN AIRPOWER HERITAGE FLYING MUSEUM

Hex
A91DFB
Octal
52216773
Decimal
11,083,259
Country
US
Tail
N687HV
Type
T34P
No current signal · last broadcast 6d ago
Flights observed
56
Distinct callsigns
1
Country
US
Last broadcast
6d ago

Last known position

Most recent position reported by Mode-S A91DFB.

Country allocation

The ICAO 24-bit address A91DFB 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
N687HV - 56 2026-07-26

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 N687HV - Jul 26, 21:55 UTCJul 26, 22:45 UTC50m
2026-07-26 N687HV - Jul 26, 19:10 UTCJul 26, 20:25 UTC1h 15m
2026-07-26 N687HV - Jul 26, 17:05 UTCJul 26, 17:40 UTC35m
2026-07-25 N687HV FLD → FLD Jul 25, 18:45 UTCJul 25, 19:05 UTC20m
2026-07-25 N687HV - Jul 25, 16:30 UTCJul 25, 16:50 UTC20m
2026-07-25 N687HV - Jul 25, 15:25 UTCJul 25, 15:45 UTC20m
2026-07-25 N687HV - Jul 25, 14:15 UTCJul 25, 14:35 UTC20m
2026-07-23 N687HV - Jul 23, 21:45 UTCJul 23, 22:50 UTC1h 5m
2026-07-23 N687HV - Jul 23, 19:15 UTCJul 23, 19:35 UTC20m
2026-07-23 N687HV FLD → FLD Jul 23, 18:10 UTCJul 23, 18:30 UTC20m
2026-07-23 N687HV FLD → FLD Jul 23, 17:05 UTCJul 23, 17:25 UTC20m
2026-07-23 N687HV - Jul 23, 13:55 UTCJul 23, 14:25 UTC30m
2026-07-22 N687HV - Jul 22, 21:30 UTCJul 22, 22:45 UTC1h 15m
2026-07-22 N687HV - Jul 22, 20:15 UTCJul 22, 20:35 UTC20m
2026-07-22 N687HV - Jul 22, 15:15 UTCJul 22, 15:40 UTC25m
2026-07-22 N687HV - Jul 22, 14:10 UTCJul 22, 14:30 UTC20m
2026-07-21 N687HV - Jul 21, 21:45 UTCJul 21, 22:05 UTC20m
2026-07-21 N687HV - Jul 21, 14:55 UTCJul 21, 15:20 UTC25m
2026-07-19 N687HV - Jul 19, 21:05 UTCJul 19, 22:55 UTC1h 50m
2026-07-19 N687HV - Jul 19, 18:10 UTCJul 19, 19:40 UTC1h 30m
2026-07-18 N687HV - Jul 18, 17:25 UTCJul 18, 19:15 UTC1h 50m
2026-07-18 N687HV - Jul 18, 14:45 UTCJul 18, 15:05 UTC20m
2026-07-18 N687HV - Jul 18, 12:15 UTCJul 18, 13:25 UTC1h 10m
2026-07-17 N687HV - Jul 17, 13:40 UTCJul 17, 13:50 UTC10m
2026-07-16 N687HV - Jul 16, 13:25 UTCJul 16, 15:30 UTC2h 5m
2026-07-11 N687HV - Jul 11, 17:10 UTCJul 11, 18:30 UTC1h 20m
2026-07-11 N687HV - Jul 11, 15:35 UTCJul 11, 16:00 UTC25m
2026-07-09 N687HV - Jul 9, 16:55 UTCJul 9, 18:30 UTC1h 35m
2026-07-02 N687HV - Jul 2, 17:10 UTCJul 2, 18:45 UTC1h 35m
2026-07-02 N687HV - Jul 2, 14:35 UTCJul 2, 15:35 UTC1h 0m
2026-06-30 N687HV - Jun 30, 19:15 UTCJun 30, 20:15 UTC1h 0m
2026-06-23 N687HV - Jun 23, 18:25 UTCJun 23, 19:34 UTC1h 10m
2026-06-20 N687HV - Jun 20, 17:10 UTCJun 20, 17:44 UTC35m
2026-06-14 N687HV - Jun 14, 20:15 UTCJun 14, 20:55 UTC40m
2026-06-13 N687HV - Jun 13, 17:10 UTCJun 13, 17:45 UTC35m
2026-06-13 N687HV - Jun 13, 14:05 UTCJun 13, 15:10 UTC1h 5m
2026-06-11 N687HV - Jun 11, 16:40 UTCJun 11, 17:05 UTC25m
2026-05-21 N687HV - May 21, 16:45 UTCMay 21, 17:15 UTC30m
2026-05-17 N687HV - May 17, 11:40 UTCMay 17, 12:01 UTC20m
2026-05-16 N687HV - May 16, 21:25 UTCMay 16, 21:50 UTC25m
2026-05-16 N687HV - May 16, 18:55 UTCMay 16, 19:15 UTC20m
2026-05-16 N687HV - May 16, 11:51 UTCMay 16, 12:11 UTC20m
2026-05-14 N687HV - May 14, 18:50 UTCMay 14, 19:40 UTC50m
2026-05-14 N687HV - May 14, 16:15 UTCMay 14, 17:10 UTC55m
2026-05-14 N687HV - May 14, 15:01 UTCMay 14, 15:25 UTC25m
2026-05-12 N687HV - May 12, 17:50 UTCMay 12, 18:45 UTC55m
2026-05-05 N687HV - May 5, 15:50 UTCMay 5, 16:40 UTC50m
2026-05-01 N687HV - May 1, 18:35 UTCMay 1, 18:55 UTC20m
2026-05-01 N687HV - May 1, 18:15 UTCMay 1, 18:30 UTC15m
2026-05-01 N687HV - May 1, 17:45 UTCMay 1, 18:10 UTC25m

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 N687HV page for operator, model, and routing details .

Mode-S A91DFB frequently asked

What is Mode-S code A91DFB?
A91DFB is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N687HV.
Where is Mode-S A91DFB registered?
Mode-S code A91DFB 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 A91DFB broadcasting right now?
No active broadcast right now. Last signal was 6d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A91DFB, octal 52216773, decimal 11,083,259.
What flights does A91DFB operate?
Mode-S A91DFB has broadcast 1 distinct callsign, including N687HV.