Checklists
Can someone explain why items on checklists aren't always confirmed by both pilots? Some actions are called by the PNF and the PF checks the item and responds, where as other items are sometimes actioned and checked by the PNF.
For example (747-400 Normal Checklist)
PNF: Flaps
PF: 20, 20, and GREEN
PNF: 20, 20, and GREEN
or
PNF: Speedbrakes
PF: ARMED