Fifteen minutes
to four
`` If anything happens so we have to land again -- well , it 's just too bad , '' Charlie said grimly . `` But we 've got to go this way . It 's something over six hundred miles in a straight line . Fifteen minutes to four , now . We have to average nearly three hundred miles an hour to get there . '' He was silent and intent over his maps and instruments as we flew on over the lofty Sierra Madre Range , and over a long slope down to the Gulf of California . Head-winds beset us as we were over the stretch of blue water , and we flew on into a storm .