YOU SAID:

they flew unbearably high, and there was danger from several conditions

INTO JAPANESE

彼らは耐え難いほど高く飛んでいました、そしていくつかの条件から危険がありました

BACK INTO ENGLISH

They were flying unbearably high and were in danger from some conditions

INTO JAPANESE

彼らは耐え難いほど高く飛んでいて、いくつかの条件から危険にさらされていました

BACK INTO ENGLISH

They were flying unbearably high and were in danger from some conditions