Thailand recently received six new helicopters. Three were S-92A, for VIP (royal family and generals) transport, while the other three were Mi-17s (for the troops). The S-92A is a 12 ton helicopter developed in the 1990s. It can carry up to 19 passengers, plus the crew of two. The S-92As for Thailand are fitted out to carry twelve passengers in greater comfort. The S-92A has a top speed of 306 kilometers an hour and endurance of about three hours.
The Mi-17 is the export version of the Russian Mi-8, a twin-engine helicopter, roughly equivalent to the U.S. UH-1 ("Huey"). 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. 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 ("Blackhawk") in the 1980s, while the Mi-8 just kept adding better engines and electronics to the basic Mi-8 frame. But 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, or an S-92A, and the larger interior is popular with many users. The S-92A is safer and more reliable than the Mi-17, but not to an enormous extent. If well maintained, Mi-17s can be nearly as safe and reliable. That said, the S-92A is definitely a more comfortable ride.