yes and no..
yes air would should and can come out if you are running the engine with them out (your shouldn't thow)
there just plugs to give access to bolts below them that holds the cylinder-head extension on
but why are you running the engine without them on, just curiosity ?
these should be kept done up with the seals still on them, it helps the engine run smooth by keeping the CKP ( crank case pressure) contained
Ash