On 23 November 2018, Bangladesh Air Guard crashed one more aircraft. This is common trend. You will see that they will blame aircraft, weather and maintenance. They will never acknowledge that poorly trained pilots who barely has few hours on actually aircraft they are supposed to fly.
Plus Bangladeshi pilots do not spend time on simulators. All modern air force pilots spend hundreds of hours on simulators if not thousands hours to practice before doing the real thing.
Add to that Russian and Chinese products are low quality and poor supply of spares and poorly maintained at their home country. Forget about the conditions at export countries.
Egyptian manage to crash brand new MiG-29M2. Again quality over quantity was choosen by Egyptian.
Think a reverse engineered bad aircraft turned into a nightmare for China AKA J-15 AKA Su-33. Chinese should have thought why Russia abandon the Su-33 before reverse engineering Su-33. J-15 crashed randomly.
Russia has limited budget and millions of projects then quality and innovation will suffer. That's what happened with Russian. So far they cancelled Su-57, T-15, Radar project, Aircraft Carrier project, Frigate project, Amphibious Assault Ship, and Submarine projects.
Nuclear missiles and ballistic missiles project chewing most of the money plus the tension with NATO, Ukraine and Georgia. Putin didn't realize that maintaining Crimea is feeding unemployed millions. Russia pays for even fresh water for Crimea.
An export customer suffers for spare, training, support and maintenance. Many examples are Su-30MKM, MiG-29K. Myanmar and India exercise sovereign rights to buy from any vendors and countries. Bangladesh is an exception. Bangladesh stick to Russia, India and China. In return Russia and China screw Bangladesh. This is the reality.