What's the O in BOUMFISH/BOUMFAH?
I was taught:
Brakes pressure check
Oil Temperatures and Pressures Green
Undercarriage down
Mixture full rich, Masters On, Magnetos on both
Fuel Selector to both, fuel contents checked
Instruments (DG aligned)
Switches, beacon, landing, strobe and auto-pilot off
Hatches and Harnesses secure