Moncrieff and Hood disappearance

Lieutenant John Moncrieff and Captain George Hood were two New Zealanders who vanished on 10 January 1928 while attempting the first trans-Tasman flight from Australia to New Zealand. Radio signals were received from their aircraft for 12 hours after their departure from Sydney, but despite a number of purported sightings in New Zealand, and many land searches in the intervening years, no trace of the aviators or their aircraft has ever been found.

Flight

The engine was started at 02:00 Sydney time on Tuesday 10 January 1928, but an over-supply of engine oil caused oil to spray on to the windscreen. This was quickly fixed, but press reporters insisting on last-minute interviews further delayed take-off and the Aotearoa did not become airborne until 02:44 (05:14 New Zealand time), immediately turning on course for New Zealand. The take-off on the Tasman flight was only the aircraft's fifth since being reassembled after delivery.

Thirty-two minutes later, at 05:46 NZ time, the officer of the watch on the trans-Tasman steamer Maunganui, 12 mi east of Sydney Heads, heard "the soft regular whirr" of an aircraft engine passing overhead, although he did not see the aircraft itself. The timing and the position of the steamer indicated an aircraft ground speed of 90 mph, about right for the intended flight.

For simplicity, Moncrieff and Hood had planned to fly a rhumb line course, intending to make landfall at Farewell Spit at the western entrance to Cook Strait. This was not the shortest course—that would have required more complicated navigation to fly a great circle course—but the difference over the trans-Tasman flight was not prohibitive. Unexpected winds could cause a drift north or south of the intended course, making an exact landfall unlikely, but the Aotearoa carried no flight instruments that could detect or compensate for such a drift. The radio had no navigational capability or function.

Arrangements for radio contact were for the aircraft to send out a continuous tone for five minutes every quarter of an hour, as the pilots had only a rudimentary knowledge of Morse code. This schedule was not adhered to, for the tone was heard for longer periods at irregular intervals. Excitement mounted in New Zealand during the day, and by early evening an estimated 10,000 people had arrived at Trentham to greet the airmen, including Dorothy Moncrieff and Laura Hood, the aviators' wives.