Originally Posted by
Small cog
lemme
As to (roll) spoilers, they operate off the Yellow system and will float up with the loss of that system.
I agree I was confused and confusing. From my fallible understanding the airbrake will stow in response to loss of power and may trail slightly open with loss of hydraulic power. The lift spoilers will remain locked down. The roll spoilers use a mechanical actuated hydraulic servo off of yellow.
Could windmilling #2 drive yellow enough to power the roll spoilers - that is the question.
A related issue is mentioned in the rudder discussion, where it is stated that
Hydraulic power is not available to the rudder from engine 2 because the power is absorbed by the standby fuel pumps. When main DC is lost, the standby fuel pumps:
• Automatically run
• Cannot be selected off.
So if yellow can't drive the rudder will it drive the roll spoilers?
This schematic seems to stack the services in order, and if nothing gets past the standby fuel pump to the rudder, it seems the roll spoilers are not going to work. I found no such reference, and appreciate your comment that they will float up a bit in response to bernoulli.
PS - this is a personnel quest along a professional curiosity.