The plans are in the right locker
A set of plans for building Vertibirds.”— In-game desciption
The Brotherhood of Steel, the Shi and the Hubologists all wanted the Chosen One to get these plans for them from the Enclave. It is unknown what his eventual decision was, however. It is possible he gave all three factions a copy of the plans: the Brotherhood chose to repay him for the completion of the mission with his own copy, and it's possible to steal them from either the Shi or the Hubologists.