The Army helicopter and regional American Airlines jet that collided over Washington are both workhorse aircraft that operate around the world on a daily basis. There were 60 passengers and four crew members on the jet, a Bombardier CRJ700, officials said. Three service members were on a training flight on the UH-60 Black Hawk helicopter. None are believed to have survived the Wednesday night collision, which caused both aircraft to plunge into the frigid Potomac River. What to know about the aircraft: SIKORSKY UH-60 BLACK HAWK There are about 5,000 Black Hawks in use around the world, according to the aviation site FlightGlobal.com. The twin-engine, four-blade helicopter is manufactured by Sikorsky, a subsidiary of defence contractor Lockheed Martin. The aircraft involved in Wednesday's collision was an Army version. There are other variants made for the Navy, Air Force and Coast Guard, and for specialised duty such as intelligence gathering. The Black Hawk made its debut in 197