Hi Aero,
Wether you want to revalidate the ratings is up to you. However, I have found that a valid ME rating is often one of the requirements for airliners. Thats why I kept mine valid. All I did was a check ride with an examinor from my local flight club.
If we take a look at JAR FCL 1.245 it says
JAR–FCL 1.245 Type and class ratings –
Validity, revalidation and
renewal
(a) Type ratings and multi-engine class
ratings, aeroplane – Validity. Type ratings and
multi-engine class ratings for aeroplanes are
valid for one year from the date of issue, or the
date of expiry if revalidated within the validity
period.
(b) Type ratings and multi-engine class
ratings, aeroplane – Revalidation. For
revalidation of type ratings and multi-engine
class ratings, aeroplane, the applicant shall
complete:
(1) a proficiency check in accordance
with Appendix 1 to JAR–FCL 1.240 in the
relevant type or class of aeroplane within the
three months immediately preceding the
expiry date of the rating; and
(2) at least ten route sectors as pilot
of the relevant type or class of aeroplane, or
one route sector as pilot of the relevant type
or class of aeroplane or flight simulator flown
with an examiner during the period of validity
of the rating.
(3) The revalidation of an IR(A), if
held, should be combined with the type/class
rating proficiency check in accordance with
Appendix 1 to JAR–FCL 1.240 & 1.295.
(c) Single-pilot single-engine class ratings
– Validity and Revalidation. Single-pilot singleengine
class ratings are valid for two years from
the date of issue, or the date of expiry if
revalidated within the validity period.
(1) All single-engine piston aeroplane
class ratings (land) and all touring motor
glider’s ratings – Revalidation. For
revalidation of single-pilot single-engine
piston aeroplane (land) class ratings and/or
touring motor glider class ratings the
applicant shall:
(i) within the three months
preceding the expiry date of the rating,
pass a proficiency check in accordance
with Appendix 1 and 3 to JAR-FCL
1.240 or Appendix 1 and 2 to JAR-FCL
1.210 with an authorised examiner in
the relevant class; or
(ii) within the 12 months
preceding the expiry of the rating
complete 12 hours flight time in a single
engine piston aeroplane or touring
motor glider including:
(A) 6 hours of pilot-incommand
time;
(B) 12 take-offs and 12
landings; and
(C) a training flight of at
least one hour’s duration with a
FI(A) or CRI(A). This flight may
be replaced by any other
proficiency check or skill test.
(iii) When the applicant holds
both a single-engine piston aeroplane
(land) class rating and a touring motor
glider rating, he may complete the
requirements in (i) above in either class
or in (ii) above in either class or a
mixture of the classes, and achieve a
revalidation of both ratings.
Quite a bit to read trough it all, but its the most complete answer I can give you
Cheers,-