The Umbrella Revolution Change_of_leadership was triggered Causation by students disaffected by the continued stalling Hindering by Beijing , and particularly the pronouncement Statement of the NPCSC on 31 August 2014 that said Telling Hong Kong had to accept an electoral process for the Chief Executive in 2017 in which up to three candidates would be pre-approved by the Election Committee – an electoral Choosing college widely seen Traveling to be loyal to Beijing authorities .

One of the probable causes Causation of stalling due to low speed was attributed Causation to turboprop engines features which change Change the propellers pitch during acceleration .