Remember: An example of a pronoun error would be putting them instead of they/those in a sentence such as: Them are the men I saw in the CCTV footage from the petrol station. Correct the two pronoun-related errors in this paragraph:
By 1977, technology had developed to the extent that Dr. Mac Cready successfully flew a 1.6 mile long figured of eight in his Gassamer Condor. With the subsequent incorporation of flight weight wonder materials such as carbon fiber and Kevlar, two years later the newly developed Gossamer Albatross achieved what was hithero thought impossible, and crossed 22 miles of the English Channel at an average height of us five feet!
After more successes in the mid-80's, an American craft, Daedelus, named after Icarus's dad piloted by a Greek cycling champ, flew more than 70 miles over the Mediterranean Sea in just under four hours, earning their creators the records for both the furthest distance flown and the longest flight duration, despite the fact that a head wind caused the plane to ditch in the sea just yards away from our intended landing point.
