17 November 2010

The Very Unorthodox Bartini/Beriev VVA-14/14M1P

I had posted back in August about how in the 1960s, the Soviet Union's lack of a blue-water navy in countering the American ballistic missile submarine fleet led to a Beriev proposal for a unique multirole ocean-going flying boat, the A-150. The basic idea of Soviet naval strategists of the day was that airborne anti-submarine forces would offer a rapid means of seeking out and destroying the SSBNs while building up its own blue-water forces.  While the Beriev A-150 never flew, another aircraft design stemming from the same basic requirements did actually fly. By the time of the new Soviet naval requirements in the 1960s, Italian designer Robert Bartini had already established himself in Russian aviation development having been an emigrant to the Soviet Union in 1923. Already known for his unorthodox approach to aeronautical problems, Bartini had long been studying the use of ground effect to improve aircraft performance. While Rostislov Alexeyev would be the name most identified with wing-in-ground effect (WIG) vehicles, or ekranoplans, Bartini's work late in his life were better described as "ekranolyots", or a vehicle that was capable of both ground effect flight like ekranoplans but also could fly at higher altitudes like normal aircraft. It was in 1965 that Bartini suggested the design of a large ocean-going VTOL amphibian anti-submarine aircraft designated VVA-14. "VVA" was the Russian acronym for a VTOL amphibian and "14" referred to the number of engines he planned to use. 

Bartini wanted VTOL performance so the VVA-14 could operate free of airfields and could be deployed and operated from any location on the Soviet periphery. In addition, its large size allowed it to float with engines off on the surface while it carried out searches for enemy submarines. The VVA-14 could transit to its patrol areas as a conventional aircraft at high altitude, and then begin its search for enemy subs as an ekranoplan. If needed, the VVA-14 could alight on the water and continue its search silently as it would not emit any of the same underwater noises as a conventional surface vessel. On 11 November 1965 the Soviet Council of Ministers granted its approval to Bartini's proposal and issued a set of operational specifications for the design that included two cruise engines, up to twelve lift jets for VTOL flight, a cruising speed of approximately 450 mph, a service ceiling of 39,000 feet, and a 2,800 mile range while carrying a 4,000+ lb weapons load. 

Unlike the ekranoplan layouts developed by the Alexeyev design bureau, the Bartinin VVA-14 used a thick wing center section that also housed the main fuselage and two Soloviev D-30 turbofan engines in dorsal nacelles. On each side of this center section were the large sponsons that not only held fuel, but also housed inflatable pontoons, giving the VVA-14 a catamaran layout when alighted on the water. Outboard of the sponsons were traditional high-aspect ratio wings. The twelve Kolesov RD36 lift engines were to be housed in the thick center wing section and not only provided vertical lift but also provided a cushion of air that was trapped between the large sponsons and the wing center section, making the VVA-14 an augmented wing-in-ground effect vehicle or ekranoplan. The VVA-14 had a bicycle landing gear with a two-wheel nose gear and a four-wheel aft gear with outrigger gears under the sponsons. 

As Bartini's design bureau (or OKB) lacked any production facilities of its own, construction of the VVA-14 prototypes was entrusted to the workshops of the Beriev OKB at Taganrog on the Sea of Azov. Two prototypes were to be built, and as the lift engines and inflatable pontoons weren't ready at the time, the VVA-14 prototype made its first flight from a conventional runway on 14 September 1972. By 1974 the inflatable pontoons were fitted and the first waterborne tests were successfully completed. By the middle of 1975 the VVA-14 had made 107 fairly uneventful flights, but the Kolesov lift engines were still not available for installation. Frustated with the lack of progress from the Kolesov engine bureau, Bartini decided forgo VTOL performance and had a second pair of Soloviev D-30 turbofans installed in pods on each side of the forward fuselage. The exhaust from the forward pair of D-30 engines would create a cushion of air under the wing center section, not unlike the arrangement favored by the Alexeyev OKB. 

The modifications were completed after Bartini's death in 1976. The forward fuselage had to be extended and  a large flap was added to the aft of the wing center section to "capture" the exhaust efflux from for forward pair of D-30 engines. Since the aircraft was no longer a VTOL, the designation was changed to 14M1P. More changes were made, the biggest one of which was the abandonment of the lightweight inflatable pontoons for a conventional flying boat hull under each sponson. This added considerable weight to the 14M1P and the first flight tests found that it no longer would leave the runway when tested out of the water. Water tests proved to be as equally unsuccessful, no matter what was done, the 14M1P refused to take to the air. Successive modifications failed to solve the problem by 1977, the Soviet Navy lost interest and the project was cancelled. Only one of the two original VVA-14 prototypes was completed and it was this prototype that became the 14M1P. In a partially disassembled state, it was donated to the Russian Federation Central Air Force Museum at Monino in 1987, where it remains to this day in poor condition, a mute testament to Bartini's unorthodox methods. 

Source: Russia's Ekranoplans: The Caspian Sea Monster and other WIG Craft (Red Star Series Volume 9) by Sergey Kommissarov. Midland Publishing, 2003, p43-56.

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