The Pilot missions are common to both the Heist Prep: Alkonost and Heist Prep: Stealth helicopter Approach Vehicle missions. Completing it once unlocks the pilot for both aircraft approaches. The Pilot mission is locked until one of the vehicles are stolen.
“There is only one pilot who combines the necessary skills for this operation with necessary indifference for international law. Retired from air force. Very experienced, very bored. In fact, he is so bored he has picked up little gambling habit, and owes some nasty people too much money. We get rid of these people, he will owe us favor, yes? He has given us coordinates... should be with you now. Some kind of house on stilts.”
“There is only one pilot we need for this operation. Air force veteran with a chest full of ribbons and no fear of causing international incident. He is perfect... but not a man who works for money. Still, there is always a way. Not so long ago his pet plane... a project of his... was stolen. You recover this, he will be in your debt, yes? He has given its location... let's do our good deed for the day.”