Can the firewall shutoff valve be reset by pushing the handle down?

The statement is true because, in the T-6A, the firewall shutoff valve operates in such a way that it can be reset by pushing the handle down. This process is essential during certain emergency procedures or when a fuel shutoff is necessary for safety reasons.

Being able to reset the valve quickly and easily is crucial in maintaining the proper functioning of the aircraft's fuel system. By pushing the handle down, pilots can restore fuel flow, allowing for a return to normal operation. This capability is designed to enhance the safety and efficiency of flight operations, which is a key principle in aircraft design and emergency management.

Other options would imply limitations or restrictions in resetting the valve that do not align with the functionality of the T-6A's systems. Hence, knowing and understanding this process is integral for T-6A operations and emergency situation management.