36 months
JAR–FCL 1.485 Responsibilities of the
applicant
(a) A pass in the theoretical knowledge
examinations given in accordance with JAR–FCL
1.490 will be accepted for the grant of the CPL(A)
or IR(A) during the 36 months from the date of
gaining a Pass in all the required examination
papers.
(b) Provided that an IR(A) is obtained in
accordance with (a) above, a pass in the ATPL(A)
theoretical knowledge examination will remain
valid for a period of 7 years from the last validity
date of the IR(A) entered in the CPL(A) for the
issuance of an ATPL(A).
Under JAA rules you have to complete both IR and CPL practical exams within 36 months otherwise you forfeit the fATPL. The fATPL status can be maintained by renewing the IR on a 7 year cycle
Why all that knowledge is deemed to disappear so quickly has never been explained lthough the regulatory authorities make a large wedge of cash from the MCQ tests that they host