Complex sentence: In addition to the ground attack mission, Sea Furies would perform combat air patrols, a total of 3900 interceptions were performed although none of the intercepted aircraft turned out to be hostile.
Split into simpler sentences: In addition to the ground attack mission, Sea Furies would perform combat air patrols. In this role a total of 3900 interceptions were carried out, although none of the intercepted aircraft turned out to be hostile.