That would largely depend on whether or not the aviation school qualified as an eligible educational institution.
You can check that by going to fafsa.gov and see if the flight school has a Federal School Code. If it does he may be eligible for the Lifetime Learning Credit, but not the American Opportunity Credit as the lessons are not a part of his degree requirements.
Please look at the following information:
https://ttlc.intuit.com/replies/3300629