The Consolidated PBY-4 was the last of the early versions of the Catalina fly boat, each of which was ordered in small numbers in the period before the Second World War. The PBY-4 was produced in smaller numbers than any other version of the Catalina – 33 were ordered on 18 December 1937, and of that total four were used for development work.
The PBY-4 was powered by two Pratt & Whitney R-1830-72 Twin Wasp engines, each of which provided 1,050hp at take-off and 900hp at 12,000ft. This gave it the best performance of any version of the Catalina, with a top speed of 197mph and a ceiling of 25,400ft. The main identifying feature of the PBY-4 was that the propellers were given spinners,
The PBY-4 only served with two US Navy squadrons – VP-1 and VP-18. Both of these units were repeatedly renamed, with VP-1 becoming VP-21, VP-1 and VP-101 while VP-18 became VP-13, then VP-26 then VP-102. By the end of 1940 both of these squadrons were part of PatWing 10, based on the Philippines.
The last four PBY-4s were used to test the prototype of the waist gun blisters, which replaced the flat windows used on earlier aircraft. These blisters gave the waist gunners a much better field of fire than the flat windows, and were adopted as a standard feature on all future versions of the Catalina, starting with the PBY-5.
The final PBY-4 was further modified to become the prototype for the PBY-5A Amphibian. While a flying boat can only operate on water, an amphibian has landing gear, allowing it to operate from land bases. On the Catalina the landing gear was made up of a nose wheel which retracted into a space below the flight deck, while the main wheels pulled back into the side of the hull between the wing struts.
Consolidated also sold two commercial versions of the PBY-4, one to American Export Airlines, where it was named Transatlantic and used to survey possible commercial routes across the Atlantic. The second was sold to the RAF, arriving in the summer of 1939. Although the RAF’s evaluation of the Catalina was interrupted by the outbreak of the war, the RAF placed an order for the first of what would become hundreds of Catalina Flying Boats to enter British service.
Engine: R-1830-72 Twin Wasp
Power: 1,050hp at takeoff, 900hp at 12,000ft
Top Speed: 192 or 197mph at 12,000ft
Gross weight: 22,295lb