WHEN Corio lifted off the water of Darwin Harbour on the morning of Friday, January 30, 1942, for Surabaya via Koepang, Aub Koch knew there were dangerous skies ahead. Recent days had seen his refuelling stop at Koepang the target of Japanese air raids and two Dutch civilian aircraft shot down. His first attempt to refuel there the previous day had also resulted in an ominous sign when repeated attempts to raise Koepang radio had received no response, in these tense days a sure indication that Japanese aircraft were about. By the time he had the Timor coast in sight and was still unable to raise Koepang he decided not to risk venturing any further and turned the big flying boat into a wide circle back towards Darwin. Typical of those flying the Qantas flag, such caution was second nature to Tasmanian-born Aub Koch. Austere and modest to a fault, he’d been a boxer and King’s Cup rower in his younger days. He was also a strong swimmer, an attribute that would save not only his own life but those of others in the days ahead. *** Once in the air, and to Koch’s relief, the half hourly reports he requested had been coming in regularly for the first stages of the flight, although the weather was poor, with low cloud forcing him to fly at around five hundred feet and ‘feel’ his way towards the coast. Koch considered such conditions as something of a mixed blessing, however, making it harder for the Japanese to see him. Then suddenly the weather cleared and the cloud base lifted to around 5000 feet, and about the same time Patterson told Koch that Koepang had missed its last half hourly radio schedule. Koch, still flying at around 500 feet, was telling Patterson to keep calling when he heard a strange rattling sound in the fuselage behind him. First officer Vic Lyne for an instant thought it must be something wrong with an engine but that idea quickly disappeared as tracer bullets flashed across the top of the flying boat and ahead of him. Although Koch could not see them behind him, attacking his flying boat were seven Japanese navy Zero fighters which had left the Netherlands East Indies island of Celebes (now Sulawesi) early that morning for an offensive sweep along