09 November 2009
After a prolonged development phase that started in 1934, the Blohm und Voss BV 138 three-engined flying boat first appeared in the skies over the Bay of Biscay in 1940. The first flying boat from Blohm und Voss, the most unique but not seen feature of the BV 138 was its tubular main wing spar which was also sealed to form a large fuel tank in addition to the more conventional fuel tanks in the wings. The flying controls were all hydraulically assisted and the crew of five was housed in the short fuselage/hull which bestowed the BV 138 it's nickname of "Die Fliegende Holzschuh" or "Flying Clog". There were enough provisions in the hull to sustain the crew for a week which allowed deployment of the BV 138 to forward positions to await further orders.
The crew included the pilot and naval observer side by side in the flight deck- in the Luftwaffe, the naval observer was actually the mission commander and only had a rudimentary amount of flight training as most of the flying was entrusted to the pilot who sat on the left. The navigation and radio compartment was located below the central engine while behind the center engine and in the wing midsection was the flight engineer's cabin whose duties included operating the fuel transfer pumps as well as topping off the engine oil in all three engines via hand pumps every 60 to 90 minutes as well as mixing coolant to keep the engines topped off as well. Two gun positions included a 20mm cannon turret in the nose ahead of the flight deck and an aft machine gun mount at the rear.
In the summer of 1943 the deployed provisioning capability of the BV 138 was used to base the flying boats on the Russian island of Novaya Zemlya to prowl on Arctic convoys bound for the port of Murmansk.
But the most unusual use of the BV 138 was that of an aerial minesweeper with a 46.6 foot diameter degaussing loop attached to the aircraft and powered by a generator in the former nose turret. As the war drew to a close, BV 138s were used to land on lakes around Berlin to evacuate wounded soldiers to Denmark.
Source: Air Enthusiast, July/August 1999. "Flugboots from Hamburg- An Outline History of Blohm und Voss Flying Boats" by Ken Wixley, p42-47.