What are the three positions of the interseat sequencing system (ISS)?

The interseat sequencing system (ISS) in the T-6A is designed to enhance safety by controlling the activation of ejection seats and ensuring that both pilot and instructor can operate the seats appropriately in various flight situations. The three positions of the ISS include BOTH, SOLO, and CMD FWD.

In the "BOTH" position, both seats are activated, allowing either crew member to eject as necessary during emergencies. The "SOLO" position is used when only one seat is needed, typically when a single pilot is flying the aircraft, ensuring that the ejection system is only armed for the active seat. The "CMD FWD" position allows the instructor pilot to have control over the ejection of the front seat while the rear remains inactive.

This configuration ensures that the seats can be managed effectively depending on the flight crew's setup, enhancing safety and operability during flight training missions. Hence, the answer detailing BOTH, SOLO, and CMD FWD is the accurate choice as it correctly captures the intended functionality of the ISS in the T-6A.