Complex sentence: The DC-10 and related MD-11 use an alternative "straight" layout, which allows for easier engine installation, modification, and access, however, has inferior aerodynamic properties when compared to the S-duct designs.
Split into simpler sentences: The DC-10 and related MD-11 use an alternative "straight" layout, which allows for easier engine installation, modification, and access. However, this has inferior aerodynamic properties when compared to the S-duct designs.