However, the Mi-8 had a larger interior, and can carry 24 troops, versus a dozen in the UH-1. The UH-1 was replaced by the UH-60 in the 1980s, while the Mi-8 just kept adding better engines and electronics to the basic Mi-8 frame. The UH-60, while weighing as much as the UH-1 (4.8 tons), could carry as much as the 12 ton Mi-8. But the Mi-8 costs about half as much as a UH-60, and the larger interior is popular with many users. Russia also offers lower rates for training pilots and mechanics. While the UH-60 is a safer helicopter to travel in, the Mi-17 accident rate is comparable if it gets good maintenance. But one of the benefits of the Mi-17 is that it can get by with less maintenance effort. The Russians build their aircraft to keep going, although with a higher accident rate, in rugged conditions and with poor maintenance. Thus high ranking politicians and military people will confidently fly in well maintained Mi-17s, while the rest of their Mi-17 fleet suffers higher accident rates because they cannot afford the same high degree (more man hours and spare parts) of maintenance.
The Mi-8 has gone through many upgrades since it was introduced in 1960s. The Mi-17 is not only the export version, it is also one of the more advanced versions. More powerful, and reliable, engines, plus better electronics and finish make this version more attractive in the international market. The Mi-8 usually weighs about 12 tons, while the Mi-17 is about 13 tons. The Russians do, after all, want to impress their foreign customers and get repeat sales. On both counts they have succeeded. The Mi-8 and Mi-17 is used in 70 different countries.
Kazakhstan is buying 20 Russian Mi-8 helicopters. Actually, they will get the Mi-17, which is the export version of the Mi-8. The Mi-8 is a twin-engine helicopter, roughly equivalent to the U.S. UH-1. But the Mi-8/17 is still in production and is the most widely exported (2,800 out of 12,000 made) helicopter on the planet. The Mi-8 is about twice the size and weight of the UH-1, but only hauls about 50 percent more cargo.