The 1.5 ton Fire Scout MQ-8B is based upon the Schweitzer 333 unmanned helicopter, which in turn is derived from the Schweitzer 330 commercial lightweight manned helicopter. Fire Scout has a payload of 272 kg (600 pounds, most of it fuel), a cruising speed of 200 kilometers, max altitude of 6,100 meters (20,000 feet), and endurance of eight hours. The U.S. Navy currently has eight MQ-8Bs and plans to acquire another 160 of them. In the last three years the navy Fire Scouts have spent over 3,400 hours in the air while operating off ships or from land bases in Afghanistan.
Proponents of the MQ-8C want a larger model because that would provide more endurance, greater stability in bad weather, and the ability to carry more weapons. The MQ-8B can carry 90 kg (200 pounds) of sensors and weapons. The MQ-8C would be able to carry about five times more. The MQ-8B has an endurance of eight hours and a cruise speed of 200 kilometers an hour. The MQ-8C would have up to three times the endurance and about the same cruise speed.
It’s already been decided to arm the MQ-8B with the Griffin (a 16 kg/35 pound guided missile with a range of 8,000 meters) and the 11.4 kg (25 pound) 70mm guided missile (based on the World War II era 70mm unguided rocket) with a range of 6,000 meters. The MQ-8C could carry heavier weapons, like the 48.2 kg (106 pound) Hellfire missile.
MQ-8C will be ready so quickly because it is using a lot of the MQ-8B technology. While the military has been slow to adopt helicopter UAVs, there is sufficient interest to keep the manufacturers at work on new models. The navy kept Fire Scout when the army dropped it because helicopters are more practical on most navy ships (for landings and takeoffs). Navy Fire Scouts have completed months of successful use on a frigate (in both the Atlantic and Pacific) and was recently in action over Libya and Afghanistan. However, the small size of the MQ-8B has limited its usefulness and proved to be more prone to wear and tear (resulting in more time spent on maintenance and less time ready for action). Note that the standard manned helicopter for ships is the ten ton SH-60 Seahawk. When flying at sea and operating off the back of a warship, size does matter.
Since the MQ-8C is based on a different manned helicopter why not give it a new identity, instead of pretending it's just a new model of an existing aircraft? The U.S. Navy has done this before. When the navy decided to build a replacement for the Cold War era F-18 they found they could get away with calling it an upgraded F-18, instead of the F-24 (the next number available since the start of the Department of Defense's standard designation system in 1962). While the F-18E looks like the original F-18 it was actually quite different. The F-18E is about 25 percent larger (and heavier) than the earlier F-18s and had a new type of engine. By calling it an upgrade it was easier for the navy to get the money from Congress. That's because in the early 1990s, Congress was expecting a "peace dividend" from the end of the Cold War and was slashing the defense budget. It was easier to get approval for an upgrade than a new aircraft design. Thus the F-18E made its first flight in 1995, and thrived in disguise. Military budgets are tight once more and an evolving aircraft is still an easier sell than a new one.