Complex sentence: Ar least 14 aircraft were completed in the USA and as of July 2011 five remain on the Federal Aviation Administration registry, including four gliders and one motorglider, which is owned by the designer.
Split into simpler sentences: Ar least 14 aircraft were completed in the USA. As of July 2011 five remain on the Federal Aviation Administration registry, including four gliders and one motorglider, which is owned by the designer.