sensors Mode-S transponder
A8BF91
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N663CA · BOEING 747-400 · operated by AC SPE 9 LLC
- Hex
- A8BF91
- Octal
- 52137621
- Decimal
- 11,059,089
- Country
- US
- Tail
- N663CA
- Type
- B744
- Flights observed
- 65
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 6h ago
Last known position
Country allocation
The ICAO 24-bit address A8BF91 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 |
|---|---|---|---|
| NCR4818 | - | 10 | 2026-04-18 |
| NCR873 | - | 5 | 2026-05-20 |
| NCR824 | - | 4 | 2026-05-10 |
| NCR822 | - | 4 | 2026-04-30 |
| NCR934 | - | 3 | 2026-05-29 |
| NCR440 | - | 3 | 2026-05-03 |
| NCR884 | - | 2 | 2026-05-07 |
| NCR812 | - | 2 | 2026-04-14 |
| NCR4971 | - | 2 | 2026-04-20 |
| NCR4286 | - | 2 | 2026-04-26 |
| NCR423 | - | 2 | 2026-05-01 |
| NCR970 | - | 1 | 2026-04-19 |
| NCR9663 | - | 1 | 2026-05-14 |
| NCR935 | - | 1 | 2026-04-19 |
| NCR919 | - | 1 | 2026-05-24 |
| NCR890 | National Air Cargo | 1 | 2026-05-24 |
| NCR862 | - | 1 | 2026-04-24 |
| NCR861 | National Air Cargo | 1 | 2026-04-23 |
| NCR841 | - | 1 | 2026-04-27 |
| NCR832 | - | 1 | 2026-05-23 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-05-29 | NCR934 | - | May 29, 23:40 UTC | May 30, 04:20 UTC | 4h 40m |
| 2026-05-24 | NCR934 | - | May 24, 23:10 UTC | May 25, 06:45 UTC | 7h 35m |
| 2026-05-24 | NCR919 | - | May 24, 09:15 UTC | May 24, 13:25 UTC | 4h 10m |
| 2026-05-24 | NCR890 | LGG → GSP | May 24, 01:00 UTC | May 24, 03:15 UTC | 2h 15m |
| 2026-05-23 | NCR832 | YYZ → ORD | May 23, 19:30 UTC | May 23, 20:50 UTC | 1h 20m |
| 2026-05-20 | NCR873 | - | May 20, 18:25 UTC | May 21, 02:35 UTC | 8h 10m |
| 2026-05-14 | NCR9663 | - | May 14, 20:50 UTC | May 15, 02:50 UTC | 6h 0m |
| 2026-05-10 | NCR824 | BGR → BGR | May 10, 06:04 UTC | May 10, 14:25 UTC | 8h 20m |
| 2026-05-10 | NCR824 | - | May 10, 01:14 UTC | May 10, 02:24 UTC | 1h 10m |
| 2026-05-09 | NCR824 | - | May 9, 18:15 UTC | May 9, 18:50 UTC | 35m |
| 2026-05-07 | NCR884 | - | May 7, 13:05 UTC | May 7, 21:05 UTC | 8h 0m |
| 2026-05-05 | NCR884 | - | May 5, 04:50 UTC | May 5, 08:55 UTC | 4h 5m |
| 2026-05-04 | NCR817 | - | May 4, 17:10 UTC | May 4, 21:10 UTC | 4h 1m |
| 2026-05-03 | NCR440 | AMM → TLV | May 3, 04:40 UTC | May 3, 05:05 UTC | 25m |
| 2026-05-02 | NCR440 | - | May 2, 18:35 UTC | May 2, 21:45 UTC | 3h 10m |
| 2026-05-02 | NCR440 | - | May 2, 08:30 UTC | May 2, 13:15 UTC | 4h 45m |
| 2026-05-01 | NCR423 | - | May 1, 20:15 UTC | May 2, 04:10 UTC | 7h 56m |
| 2026-05-01 | NCR423 | - | May 1, 14:00 UTC | May 1, 16:50 UTC | 2h 50m |
| 2026-04-30 | NCR822 | - | Apr 30, 22:20 UTC | May 1, 09:05 UTC | 10h 45m |
| 2026-04-30 | NCR821 | JFK → STN | Apr 30, 15:25 UTC | Apr 30, 17:00 UTC | 1h 35m |
| 2026-04-29 | NCR829 | GSP → EMA | Apr 29, 22:45 UTC | Apr 30, 08:15 UTC | 9h 29m |
| 2026-04-29 | NCR828 | HSV → OST | Apr 29, 12:40 UTC | Apr 29, 13:55 UTC | 1h 15m |
| 2026-04-28 | NCR826 | - | Apr 28, 21:55 UTC | Apr 29, 08:45 UTC | 10h 50m |
| 2026-04-28 | NCR825 | - | Apr 28, 15:35 UTC | Apr 28, 16:45 UTC | 1h 10m |
| 2026-04-28 | NCR4808 | - | Apr 28, 02:55 UTC | Apr 28, 11:35 UTC | 8h 40m |
| 2026-04-27 | NCR841 | - | Apr 27, 15:50 UTC | Apr 27, 19:50 UTC | 4h 0m |
| 2026-04-27 | NCR822 | - | Apr 27, 13:15 UTC | Apr 27, 13:40 UTC | 25m |
| 2026-04-26 | NCR822 | - | Apr 26, 20:45 UTC | Apr 27, 07:20 UTC | 10h 35m |
| 2026-04-26 | NCR822 | - | Apr 26, 20:30 UTC | Apr 26, 20:40 UTC | 10m |
| 2026-04-26 | NCR820 | JFK → PRN | Apr 26, 13:35 UTC | Apr 26, 15:45 UTC | 2h 10m |
| 2026-04-26 | NCR4286 | - | Apr 26, 00:15 UTC | Apr 26, 00:45 UTC | 30m |
| 2026-04-25 | NCR4286 | - | Apr 25, 21:40 UTC | Apr 25, 21:45 UTC | 5m |
| 2026-04-25 | NCR4287 | - | Apr 25, 15:15 UTC | Apr 25, 15:30 UTC | 15m |
| 2026-04-24 | NCR4902 | - | Apr 24, 23:00 UTC | Apr 25, 08:10 UTC | 9h 10m |
| 2026-04-24 | NCR815 | PRG → MXP | Apr 24, 18:25 UTC | Apr 24, 19:25 UTC | 1h 0m |
| 2026-04-24 | NCR4977 | - | Apr 24, 07:50 UTC | Apr 24, 14:35 UTC | 6h 45m |
| 2026-04-24 | NCR862 | - | Apr 24, 04:25 UTC | Apr 24, 04:50 UTC | 25m |
| 2026-04-23 | NCR861 | NRT → SUB | Apr 23, 14:30 UTC | Apr 24, 02:50 UTC | 12h 20m |
| 2026-04-22 | NCR873 | - | Apr 22, 21:50 UTC | Apr 23, 08:40 UTC | 10h 50m |
| 2026-04-22 | NCR873 | - | Apr 22, 14:55 UTC | Apr 22, 16:30 UTC | 1h 35m |
| 2026-04-22 | NCR824 | - | Apr 22, 01:35 UTC | Apr 22, 09:55 UTC | 8h 20m |
| 2026-04-21 | NCR823 | JFK → LGG | Apr 21, 18:40 UTC | Apr 21, 22:40 UTC | 4h 0m |
| 2026-04-21 | NCR873 | JFK → TLV | Apr 21, 05:35 UTC | Apr 21, 15:55 UTC | 10h 20m |
| 2026-04-20 | NCR873 | - | Apr 20, 23:10 UTC | Apr 21, 01:35 UTC | 2h 25m |
| 2026-04-20 | NCR4971 | - | Apr 20, 08:20 UTC | Apr 20, 16:40 UTC | 8h 20m |
| 2026-04-19 | NCR4971 | - | Apr 19, 20:35 UTC | Apr 20, 05:20 UTC | 8h 45m |
| 2026-04-19 | NCR970 | - | Apr 19, 16:05 UTC | Apr 19, 16:15 UTC | 10m |
| 2026-04-19 | NCR935 | - | Apr 19, 02:40 UTC | Apr 19, 08:15 UTC | 5h 35m |
| 2026-04-18 | NCR934 | - | Apr 18, 23:30 UTC | Apr 19, 00:25 UTC | 55m |
| 2026-04-18 | NCR814 | HSV → LGG | Apr 18, 19:05 UTC | Apr 18, 20:35 UTC | 1h 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 N663CA page for operator, model, and routing details .