AIR NAVIGATION.

Auckland Star, Volume LXXI, Issue 103, 2 May 1940, Page 8

AIR NAVIGATION.

CELESTIAL CHECKS. . . 1 Celestial position checks were taken on every voyage when weather conditions permitted, said the Aotearoa's navigating officer, Mr. W. J. Craig, when questioned on the return flight. Radio was not sufficiently accurate in the middle of the Tasman Sea, for the slightest error made a big difference. The radio direction-finding stations at Liverpool, New South Wales, and at Musick Point, Auckland, he said, were of great assistance. He had found that the Liverpool station was above the average. So far the station on Lord Howe Island had not been operated, but when it came in the accuracy with which they could fix their position by radio direction finding would be increased by 50 per cent. "On each of the ,11 crossings we.have made we have been able to get celestial checks," he added. Most of the bad weather that had been encountered could be classed as "local," the centres extending for a few hundred miles, and the flying boat on every occasion had run out of the bad conditions. "We reached an altitude of 11.000 feet this morning," he said. "That is about the maximum height we have flown the Tasman. So far we have had no electrical storms of any consequence." The New Zealand landfall that was invariably aimed at in crossing from the east, he continued, was between the Manukau .and Kaipara harbours. The objective had always been reached, and on no occasion had the flying boat been more than five miles out, either to the north or south. Questioned concerning the degree of accuracy in navigating by dead reckoning—that was without radio or sun sights—Mr. Craig said that in clear weather the wind speed could be determined to within two miles an hour, and its' direction to within two degrees.