Interesting point raised about the MEP class rating. I had been led to believe that differences training is indeed mandatory, so given the different view held here I decided to check on it.
The first port of call was
JAR-FCL 1. Section 1.215 deals with Class Ratings and can be quoted as follows.
Originally Posted by JAR-FCL 1.215
JAR–FCL 1.215 Class ratings (A)
(a) Divisions. Class ratings shall be
established for single-pilot aeroplanes not
requiring a type rating as follows:
...
(6) all multi-engine piston aeroplanes
(land); and
...
It goes on to say:
Originally Posted by JAR-FCL 1.215
(b) Listings
(1) Class ratings for aeroplanes will
be issued according with the associated
administrative procedures accepted by the
JAA. In order to change to another type or
variant of the aeroplane within one class
rating, differences or familiarisation training is
required.
Note the use of the word
required rather than
recommended. Further on, part 1.235 refers to privileges and states:
Originally Posted by JAR-FCL 1.235
JAR–FCL 1.235 Type and class ratings – Privileges, number and variants
(a) Privileges. Subject to JAR–FCL
1.215(b) & (c) and JAR-FCL 1.220(a) & (b)
above, the privileges of the holder of a type or
class rating are to act as a pilot on the type or
class of aeroplane specified in the rating.
Finally, the second half of Table 1 of the
JAA class & type ratings suggests that differences training applies when moving between variants of the MEP class rating.
These are the bits of info I managed to find, what I couldn't find is any UK exemption or differences filed by the CAA. One could be forgiven for believing that differences training is required between between MEP aircraft.