Originally Posted by
Dave Therhino
But yes, if it sticks open you will almost always end up with a shutdown, and if it sticks on both engines it's likely to be a forced landing. The AD was issued because the first few flights after a storage period have a risk of dual engine shutdown that is quite high.
Dave, do you know why this is 737 specific and doesn't apply to the CFM powered A320? That check valve is usually considered part of the engine and I'd expect if they used the same valve on both the CFM56-3 and -7, I would have expected them to use the valve on the CFM56-5 on the A320.