From
LASORS Section F:
Re-validation of Single-Engine Piston - SEP (Land) or TMG Class Ratings
May be revalidated by passing a Licensing Proficiency Check (LPC) with an authorised Flight Examiner (FE(A)) or Class Rating Examiner (CRE(A)) within the three months preceding the expiry date of the rating without loss of validity period.
Alternatively, both ratings may be revalidated by flying experience by producing logbook evidence to an authorised examiner of having completed the following within the 12 calendar months preceding the expiry date of the rating:-
i. 6 hours as pilot-in-command
ii. 12 take-offs and landings
iii. a training flight of at least 1 hour's duration with a FI(A) or CRI(A) who must countersign the appropriate logbook entry.
There is more detail on this in LASORS, but that's the basic requirements.
FFF
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