Would presumably sane people head off into the vastness of the Pacific with no plan B...I doubt it.
Depending on the remaining calculated fuel state, Fred would have had a divert to ??? at a certain point.
...' If we cant see Howland within the next 15 mins, we must now head for ..'
Nukuamoro /Gardner (with a stiff quartering head/x wind) ?
..or turn back to the huge span of the Gilbert Is across the track ? ( with a ubeaut tail wind).
Maybe Amelia rejected that advice as with Africa, to keep looking.
Perhaps we'll never know.
How's Dave Billings going. Any news of the New Britain search? .