Shooting at timed airstrikes

In the rules it states that timed airstrikes can be engaged by the opponent by any units using reaction orders. But do you need to destroy the plane to stop the airstrike or just pin it. Pinning it seems possible but getting enough hits to kill it seems unlikely unless there are a lot of units on ambush fire.

If you pin it and that stops the airstrike can your opponent unpin it on a later turn and the airstrike continues the following turn or is it just done.

I assume it's done, just want to check for thoroughness as I'm asking the first part of the question.

Once a timed airstrike is pinned it is lost since it is a timed mission and that turn is the only time it is allowed to attack. It can't come back later.

If you pin it, the timed strike is gone.
A very weird incident can occur though (sanctioned by Warwick), where you do damage the aircraft, and the consequent morale test results in a successful BTCOD (treat all aircraft as regular). Then the timed attacks is cancelled, but the aircraft remains in table to pound your enemies until his ammo is out! (Or shot down/driven away)