"HMRC’s stance is that no deduction should normally be permitted under Section 336 ITEPA 2003 for expenses incurred by an employee for external education. This is so even where the subject of the education is closely relevant to the nature of the employment. The expenses are not deductible because they are not incurred in the performance of the duties of the employment."
In simple terms, if the type rating was done by the employer as "part of the performance of the duties" then there may be a slim chance , on the other hand if the type rating was given by a "third party" and your contract states " on successful completion of the rating etc etc" , in other words your "contract of employment " started after completion of the rating then the answer is No. Of course this assume you have an employment contract and are paying tax within the HMRC environment, if you are working abroad than forget it.