It seems like a pretty simple question but I've never found a good answer. It was always left pretty vague. I always heard it was an engine malfunction or something of that sort. Can anyone give me a good answer? Note: I haven't played Resident Evil Zero in a long time.

I have a personal theory. Wesker broke it. In RE1 Rebecca said that she had serviced the helicopter a few days before the mission, but something went wrong with the engine. I'm guessing Wesker messed the helicopter up to make them land in raccoon forest

It could be anything from; Drunk Driving to Sabotage.

I think Wesker sabotaging it is the actual/official reason, although GL has a good point.

Yeah Wesker must have messed around with before hand

I thought it was common knowledge that Wesker sabotaged it. He needed them to land. He needed battle data. So he sabotaged the engine. My personal theory is that he placed a small explosive on some part of the engine and detonated it remotely.

The goal was to lure STARS into the mansion, not the woods around it. I still think Rebecca fucked the engine up when she monkeyed with it.

You're right, he should have planned to crash land the chopper in the mansion's foyer.

Wesker couldn't crash land it anywhere, he wasn't piloting it.

You and your damn technicalities.

I just rain logic down on everyone around me.

I think Richard did it. I mean, come on.

Did you see his face in the opening cutscene of RE0? Looked pretty guilty.