Complex sentence: The Boeing/Sikorsky RAH-66 Comanche was an advanced U.S. Army military helicopter intended for the armed reconnaissance role, incorporating stealth techniques, and designed to designate targets for the AH-64 Apache.
Split into simpler sentences: The Boeing/Sikorsky RAH-66 Comanche was an advanced U.S. Army military helicopter intended for the armed reconnaissance role, incorporating stealth techniques. Also, it was to designate targets for the AH-64 Apache.