Blackfyre

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You picked up bandit at approximately 42nm in the track, it is fine and how it should be.
Beside that, why are you keeping low? If you gain altitude (like AI did), you will be able shoot down him from far more distant range, therefore keeping yourself safer (imagine Flanker had R-27ET). Also, I'd suggest take less missiles and tanks versus single target, because these create drag, so it is more difficult to gain speed.
I've played through your mission, designated target at 46 nm, shot him down with single missile launched from 33nm.