Simviation Forums

What are they for? i only see them on props?

They're for controlling airflow through the engine cowling.

They need to be open on the ground to let extra air through at slow speeds.. and open during climbs at full power when the extra cooling is needed... They can be closed during cruise, as the air is flowing pretty well and the engine isn't working hard.  And on some planes, varying degrees of open-ness are required.

It's all about engine temperature management...

thanks guys