The breakdown was due to a mechanical failure.

抛锚是机械故障造成的。

《牛津词典》

The airplane crash was caused by mechanical failure.

这一次坠机事件是因为机械故障造成的。

youdao

The crash was likely caused by mechanical failure and not hostile fire, Crawley added.

Crawley补充说，此次坠机事件可能是由于机械故障引起的，而不是被利比亚方火力击中所致。

youdao

But the Frenchman's back wheels locked up early on and he had to pull out due to mechanical failure.

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Ryan Farquhar and John McGuinness retired during the race because of mechanical failure.

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Note: We changed this story on 15th February 2013 to reflect the fact that the accident was caused by structural rather than mechanical failure.

BBC: Ely helicopter crash