On the Baron 58 when should the cowl flaps be opened and closed?

Follow the checklist available from the Kneeboard.

 

In brief - open for start and taxi, for take off and full power climb, close for cruise/climb, cruise, descent and approach. CHT is the most useful gauge for when you need them cracked open in normal flight - generally, you will have them closed.

 

For checklist referral you can also d/l what you need from http://www.freechecklists.net/simchecklists.asp

 

B)

Always open for start up.  Monitor cyclinder head temperatures, but generally speaking, if outside air temps are above freezing, you will want the flaps open for all ground operations and climb.  Close them for cruising so long as cylinder head temps are within normal limits.  Closed during descent, and landing, open them again after landing.

Harmony!  :Whistle: