Cabin air quality seen as airworthiness issue.

机舱空气质量被视为适航条件之一…。

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Foremost among the recommendations: the safety board said all of the unlimited class aircraft like the P-51 Mustang should be made to demonstrate their airworthiness at racing speeds before participating in a public air race.

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The Air Force was asked to stand by for possible mercy flights, but its planes are old and of dubious airworthiness.

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