russian documents opened to the public in march 2003 showed that the kgb had changed their own investigation of the accident. in addition to this, one government and two military investigations. the kgb's report removed many conspiracy thoughts, instead of showing the actions of air base personnel added to the crash. the report says that an air traffic controller made gagarin have old weather information. but by that time of his flight, conditions had become very bad. ground crew also left fuel tanks on the aircraft. gagarin's planned flight needed good weather and no outboard tanks. the investigation ended, saying that gagarin's aircraft entered a spin, either because of a bird strike or because of a sudden move to avoid another aircraft. because of the old weather report, the crew thought their altitude to be higher than it actually was, and could not properly react to bring the mig-15 out of its spin.