Indeed, whilst the Chinese allegedly strapped prisoners onto kites in the sixth century, and Elmer of malmesbury was recorded as having glided for more than an eighth of a mile before crashing and breaking both his legs, it was not until the start of the 1900s that scientific attempts are made to get a man off the ground under his own steam. These bicycles on wheels might seem comical to today’s aeronauts, but in 1912 they are good enough to help Gabriel plain scoop a prize of 10,000 francs, having allegedly flown his contraption more than a meter off the ground for distance of 10 meters.
What are the two verb tense errors in that?