Unlock? – F18 Flight Simulator Review

Anyone know why or how to unlock the 3rd aircraft in series 1? The first 5 planes required 6K coins for each to be able to unlock but won't let me. I got 1, 2, 4, and 5th aircraft unlocked but won't allow the 3rd even though it takes the same amount of coins to unlock like the others?
Review by Ccnyc2010 on F18 Flight Simulator.