Reading the OP more carefully:
Originally Posted by
AeroTech
Extract from FAR 25.149:
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Does it mean that the rudder and the aileron are oversized to cope with engine failure so that the banking angle will not exceed 5 degrees?
No.
The VMC rule you quoted cites a 5 degree bank angle to be used for the demonstration of straight flight. It does not mean that an engine failure will always result in a bank of 5 degrees or less.
25.143 also addresses engine failure, and the following is extracted from AC25-7A which provides guidance on interpretation of the regulation:
c Controllability Following Engine Failure. Section 25.143(b)(1) requires the airplane tbe controllable following the sudden failure of the critical engine.
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Additionally, the airplane will be considered to have reached an unacceptable attitude if the bank angle exceeds 45 degrees during the recovery.
So 25.143 allows up to 45 degrees bank following an engine failure.
Additionally, a "dynamic VMCA" test is required as part of compliance to 25.149. The guidance for conduct of this test specifies heading control, but does not constrain the bank angle directly.