How do I get the Condor VTOL out of the park for the related vehicle delivery mission?

If you've reached respect level 20, you can buy Notoriety Wipe: Police from the Upgrade Store. This adds a number to your cell phone's contact list which, as the name implies, completely removes your police notoriety when called.

Call that number as soon as you enter the Falcon and your notoriety spikes — you'll be able to fly off at your leisure, unmolested by local law enforcement. Avoid causing any property damage along the way, and you'll be allowed to land peacefully, as well.

I completed the game's Campaign (missions). And that place was still there even though STAG was evicted from Steelport. There are two Condors and an F-69 parked there. No STAG soldiers or anything. Took one for Vehicle Theft and one for myself.

Without using the "police forgiveness" perk, I was able to get the Condor out of there by immediately switching to fixed-wing mode and then flying low through the skyscrapers; this somehow prevented me from picking up random ground fire. It was a close-run thing once I got to the airport & the soldiers massed there, but doable.