I was under the impression that it was 6 months but then I checked AMC FCL 1.261 (C) and found this.
14. The Head of Training, or a nominated representative, is required to certify that all training has
been carried out before an applicant undertakes a skill test for the type rating to be included in the pilot’s
licence. It is not uncommon for an approved TRTO to be unable to provide, or have direct supervision over
any training that is required to be carried out on an aeroplane conducted by a third party such as the
operator. In such cases, and with the agreement of the approving Authority, a TRTO Course Completion
Certificate may be issued confirming completion of ground and STD flight training. Confirmation of the
completion of aeroplane training should then be provided by the organisation undertaking this training, as a
requirement for issue of the type rating. The period of time between any two phases of training should not
exceed 60 days otherwise refresher training at the discretion of the Authority will be required.
So 60 days then?
bjb