Will the Skywatch HP (SKY899) directly replace the standard Skywatch (SKY497)?
No. The mounting rack and connector for the system processors (TRC899 and TRC497) are the same. In addition, both systems utilize the same NY-156 antenna (non TCAS I). However, the wiring of the connector for each processor is different. Therefore, upgrading the SKY497 (Skywatch) to SKY899 (Skywatch HP) would be a wiring change only.