The Air Tractor AT-400 is a family of agricultural aircraft that first flew in the United States on September 1979 . Type certification was awarded to Air Tractor in April 1980 . Of low-wing monoplane taildragger configuration, they carry a chemical hopper between the engine firewall and the cockpit .
EPI, Inc. has worked on several engine conversion programs, including programs to develop STC'd retrofit packages to install the Orenda ™ certified 600 HP liquid-cooled powerplant into the Aero-Commander 685 and the Air Tractor 401 aircraft.
Diamonds of Russia.
Russia, as well as Canada and Australia - a country with huge mineral reserves. All three countries have become important producers of diamonds. Actually Russia is the world's second country, on extraction of diamonds, (after Botswana). Russia currently produces about 21% of the diamonds in the world. Extraction of diamonds in Russia is carried out generally in the Republic of Sakha in northeast Russia, near the Arctic Circle.
Today in the world the majority of industrial diamonds — synthetic stones. In 2010 the Geological service of the USA has reported:
"About 1,4% of all industrial diamonds, and on a share of synthetic diamonds — the rest fall to the share of natural diamonds". The cost of production of artificial diamonds has significantly decreased for the last several decades. Now it is cheaper to do induustrial diamonds, than to extract them.
In 2010 world production of synthetic industrial diamonds was about 4,38 billion carats for the sum from 1,65 to 2,50 billion US dollars. On average the price is about 50 cents for carat or less. The Chinese companies produce more than 90% of synthetic diamonds.
Russia as the country produces more precious diamonds than any other countries, including Botswana. It produces diamonds and their artificially produce for a long time. Russians have considerable experience in extraction of diamonds, productions of synthetic diamonds, and also use of diamonds as industrial material. JSC ALROSA and the state diamond-mining companies of Russia, makes more natural diamonds, than any other companies in the world and are a large producer of synthetic diamonds.