When it takes to its wings, the Navy’s 140,000-pound flying boat will be the largest flying vessel in the world. The winged battleship, known as XPB2M-1, built by The Glenn L. Martin Company, has a wingspread of 200 feet, its 117-foot hull has two decks. and it can carry enough fuel for its four 2,000-horsepower Wright duplex Cyclone engines to fly it nonstop across the Atlantic ocean and back. It will carry guns, bombs and torpedoes. The craft is intended for high-altitude operation. Cruising speed probably will be about 150 miles an hour, with a top speed near 200 miles.