Originally Posted by
sabenaboy
So here's what I dislike about the A320 FCOM: the lack of correct clear information! Surely one would think that rudder trim should be reset if rudder deflection is affected. Why use the word "may" in the FCOM?
It either does reduce rudder deflection in certain conditions or it doesn't!
From what I've read, FCOMs are a bugbear - not least because the procedure in writing them was to write them first in French, then have them translated into English (among other languages). This makes sense in terms of having them all say exactly the same thing no matter what language they are read in, but it definitely results in some curious use of language from the point of view of a native English speaker.
In this case however, I suspect there is method behind the choice of words. Technical writing exists in a state that is balanced on the edge of conciseness versus accuracy. If it is stated that something "will" have an effect, then it implies that all failure modes have been tested and behaviour has been shown to be constant. The use of "may" allows for the existence of failure modes that were not covered in the design and testing regime.