Actually I just read the 10K filing.... the 5 aircraft were to come from the E-170s coming offline the S5 Delta op..... It clearly states 16 E170s being replaced by 16 E175's .... 10 E-170s going to UAL express operations... and 5 going to Frontier ... with 1 left unallocated......

Now...that might conflict with what has been said... but it is clear as day in the 10K filing.