A total of 222 flight crew members of a Japanese commercial airline company responded anonymously to a preliminary questionnaire with respect to their fatigue. We analyzed the data of 196 flight crew members of two large airline companies who had experience of long sequences of transmeridian international flights on B767, B777and B787. For analyzing the pilots' fatigue, we used long-haul operations (8 hours or more in length), two-person crews each consisting of a captain and a first officer without relief crews, night time operations between 22:00-05:00 and flights around departure or arrival times during windows of circadian low (WOCL;02:00-06:00), flights of multiple time zones and early morning operations before 7:00. Flight crews of Company A and Company B also felt fatigue strongly on the long-haul operations. These long-haul operations were placed before and after middle range Asian operations. Flight crews of Company A felt more tired than flight crews of Company B because their long haul operations were performed by only two-person crews. The reason why the flight crews experienced strong fatigue during the night operations were because they could not be taking naps before and after the operations. Also, in transmeridian flights, they felt strong sleep disturbance, dullness and circadian disruptions. Flight crews strive to control their physical conditions before the flight, but they often do not necessarily succeed. Therefore, they claim to have an interval of two days before the early morning flights, two days or more after late night flights, four days after the westward and the eastward flights. They would like to take a nap at the bunk on an airplane several times rather than only once. In addition, they claimed taking a nap of 143.0 min if they could take a nap before flights and 207.4 min. if they could not take it.