sensors Mode-S transponder

A631BA

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N499CA · CESSNA 402 Businessliner · operated by HYANNIS AIR SERVICE INC

Hex
A631BA
Octal
51430672
Decimal
10,891,706
Country
US
Tail
N499CA
Type
C402
No current signal · last broadcast 23h ago
Flights observed
87
Distinct callsigns
20
Country
US
Last broadcast
23h ago

Last known position

Most recent position reported by Mode-S A631BA.

Country allocation

The ICAO 24-bit address A631BA 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 20 distinct

Callsign Airline Flights Last seen
KAP519 Cape Air 15 2026-05-29
KAPT58 - 10 2026-05-12
KAPT818 - 6 2026-05-14
KAPT787 - 6 2026-06-01
KAP111 Cape Air 6 2026-05-23
KAPT978 - 4 2026-05-21
KAPT605 - 4 2026-05-20
KAP916 Cape Air 4 2026-04-24
KAP747 Cape Air 3 2026-04-26
KAP6789 Cape Air 3 2026-04-23
KAP616 Cape Air 3 2026-05-25
KAP1271 Cape Air 3 2026-05-22
N499CA - 2 2026-05-18
KAPT9 - 2 2026-04-20
KAPT747 - 2 2026-04-27
KAPT40 - 2 2026-04-15
KAP3081 Cape Air 2 2026-05-23
KAPT388 - 1 2026-04-22
KAPT1279 - 1 2026-05-01
KAPT111 - 1 2026-05-11

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-06-01 KAPT787 - Jun 1, 20:55 UTCJun 1, 22:05 UTC1h 10m
2026-06-01 KAPT787 - Jun 1, 17:45 UTCJun 1, 20:00 UTC2h 15m
2026-05-29 KAP519 BOS → ALB May 29, 19:00 UTCMay 29, 19:10 UTC10m
2026-05-29 KAP519 BOS → ALB May 29, 16:30 UTCMay 29, 17:50 UTC1h 20m
2026-05-29 KAP519 BOS → ALB May 29, 13:50 UTCMay 29, 15:00 UTC1h 10m
2026-05-29 KAP519 BOS → ALB May 29, 12:55 UTCMay 29, 13:05 UTC10m
2026-05-29 KAP519 BOS → ALB May 29, 11:30 UTCMay 29, 11:40 UTC10m
2026-05-28 KAP519 BOS → ALB May 28, 19:10 UTCMay 28, 19:25 UTC15m
2026-05-28 KAP519 BOS → ALB May 28, 16:05 UTCMay 28, 17:45 UTC1h 40m
2026-05-28 KAP519 BOS → ALB May 28, 13:55 UTCMay 28, 15:00 UTC1h 5m
2026-05-28 KAP519 BOS → ALB May 28, 13:10 UTCMay 28, 13:20 UTC10m
2026-05-28 KAP519 BOS → ALB May 28, 11:35 UTCMay 28, 11:45 UTC10m
2026-05-27 KAP519 BOS → ALB May 27, 19:00 UTCMay 27, 19:10 UTC10m
2026-05-27 KAP519 BOS → ALB May 27, 16:15 UTCMay 27, 17:40 UTC1h 25m
2026-05-27 KAP519 BOS → ALB May 27, 13:55 UTCMay 27, 15:00 UTC1h 5m
2026-05-27 KAP519 BOS → ALB May 27, 13:10 UTCMay 27, 13:20 UTC10m
2026-05-27 KAP519 BOS → ALB May 27, 11:35 UTCMay 27, 11:45 UTC10m
2026-05-25 KAP616 BOS → ACK May 25, 18:45 UTCMay 25, 19:10 UTC25m
2026-05-25 KAP3082 MVY → BOS May 25, 17:55 UTCMay 25, 18:25 UTC30m
2026-05-25 KAP616 BOS → ACK May 25, 16:35 UTCMay 25, 17:00 UTC25m
2026-05-25 KAP3241 MVY → BOS May 25, 15:30 UTCMay 25, 16:00 UTC30m
2026-05-25 KAP616 BOS → ACK May 25, 14:35 UTCMay 25, 14:50 UTC15m
2026-05-23 KAP111 BOS → LEB May 23, 22:05 UTCMay 23, 22:50 UTC45m
2026-05-23 KAP6199 HYA → BOS May 23, 20:05 UTCMay 23, 20:30 UTC25m
2026-05-23 KAP111 BOS → LEB May 23, 18:40 UTCMay 23, 19:10 UTC30m
2026-05-23 KAP3081 MVY → BOS May 23, 17:25 UTCMay 23, 17:55 UTC30m
2026-05-23 KAP111 BOS → LEB May 23, 16:30 UTCMay 23, 16:40 UTC10m
2026-05-22 KAP111 BOS → LEB May 22, 22:15 UTCMay 22, 23:00 UTC45m
2026-05-22 KAP3181 MVY → BOS May 22, 20:45 UTCMay 22, 21:15 UTC30m
2026-05-22 KAP111 BOS → LEB May 22, 19:00 UTCMay 22, 19:30 UTC30m
2026-05-22 KAP3081 MVY → BOS May 22, 17:35 UTCMay 22, 18:05 UTC30m
2026-05-22 KAP111 BOS → LEB May 22, 16:35 UTCMay 22, 16:50 UTC15m
2026-05-22 KAP1271 HYA → ACK May 22, 01:15 UTCMay 22, 01:30 UTC15m
2026-05-21 KAP1271 HYA → ACK May 21, 22:00 UTCMay 21, 22:40 UTC40m
2026-05-21 KAP1271 HYA → ACK May 21, 19:45 UTCMay 21, 20:30 UTC45m
2026-05-21 KAPT978 - May 21, 13:45 UTCMay 21, 14:10 UTC25m
2026-05-21 KAPT978 - May 21, 10:45 UTCMay 21, 11:50 UTC1h 5m
2026-05-20 KAPT605 - May 20, 10:50 UTCMay 20, 11:40 UTC50m
2026-05-19 KAPT978 - May 19, 11:40 UTCMay 19, 13:00 UTC1h 20m
2026-05-18 N499CA BBX → HYA May 18, 20:40 UTCMay 18, 22:05 UTC1h 25m
2026-05-17 N499CA - May 17, 12:35 UTCMay 17, 14:15 UTC1h 40m
2026-05-14 KAPT818 - May 14, 17:45 UTCMay 14, 19:30 UTC1h 45m
2026-05-13 KAPT605 - May 13, 17:35 UTCMay 13, 19:10 UTC1h 35m
2026-05-12 KAPT58 - May 12, 20:55 UTCMay 12, 21:55 UTC1h 0m
2026-05-12 KAPT58 - May 12, 16:40 UTCMay 12, 18:00 UTC1h 20m
2026-05-11 KAPT111 - May 11, 15:15 UTCMay 11, 16:55 UTC1h 40m
2026-05-06 KAPT58 - May 6, 16:15 UTCMay 6, 17:00 UTC45m
2026-05-05 KAPT58 - May 5, 18:55 UTCMay 5, 19:50 UTC55m
2026-05-05 KAPT978 - May 5, 14:05 UTCMay 5, 16:00 UTC1h 55m
2026-05-04 KAPT787 - May 4, 18:55 UTCMay 4, 20:00 UTC1h 5m

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 N499CA page for operator, model, and routing details .

Mode-S A631BA frequently asked

What is Mode-S code A631BA?
A631BA is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N499CA.
Where is Mode-S A631BA registered?
Mode-S code A631BA 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 A631BA broadcasting right now?
No active broadcast right now. Last signal was 23h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A631BA, octal 51430672, decimal 10,891,706.
What flights does A631BA operate?
Mode-S A631BA has broadcast 20 distinct callsigns, including KAP519, KAPT58, KAPT818, KAPT787, KAP111.