Around-the-World phase IV, part 5: the longest flight of the whole trip, 2027 nautical miles from Hilo, Hawaii to Monterey, California, using 2 supplemental tanks in the cabin. Preparation included finding a day with tailwinds. First attempt failed, had to return to Hawaii after 90 minutes, as the HF radio malfunctioned. Too much fuel to land, had to burn fuel to decrease weight. Fixed the radio issue, and succeeded the next day.