Malta mod question: magic?

[planespotter]

I am in mission 11 in the Malta mod flying RAF 261 Sq. We are sent up to intercept Luftwaffe fighter sweep.

I am crap Hurricane pilot and do not get altitude in time and we are bounced and many Hurricanes lost. That sucks, and then Luftwaffe goes home.

This is the awesome part.

I follow Luftwaffe to Sicily, to try to bounce them on their landing, get some revenge.

Sneaky idea, yeah?

No.

As I get near Luftwaffe airfield CR42s appear from nowhere and bam, knock out my engine.

I land in the desert on fire, end of my mission for me!

How do I create this type of mission so that enemy 'guards' appear/spawn when you get near a target?

What is trigger language? Any?