In 1971, a Swearingen Merlin III placed first in the 5,851-mile transatlantic and transcontinental London to Victoria (British Columbia) air race. The Merlin III is an eight to 11 seat executive transport that offers nearjet speed while consuming less than half the fuel. It also claims the longest range (2,860 miles) of any business propjet with cruising speeds up to 325 mph.
Swearingen introduced the Merlin IIIB in September 1978 with new AiResearch powerplants producing 900-shp each and turning four-blade propellers equipped with synchrophasers. The IIIB has a 2,425-nm IFR range and a service ceiling of 32,500 feet. To the typical business user, this range capability permits a number of average 300- to 500-mile trips during one day without the need to refuel at out-of-the way places. Subsequent models featured a reshaped fairing between the wing root and fuselage for better aerodynamic flow and a new horizontal stabilizer leading edge contour for more efficient trim capability.
The luxury interior in the Merlin is one of the most lavish of any business airplane, and the cabin is a spacious 5 feet wide with 23 feet of usable length. Sea-level pressurization can be maintained up to 16,800 feet, and at 31,000 feet, the cabin atmosphere is still equivalent to that at 7,400. Power is provided by two AiResearch turboprops rated at 840 shp and equipped with single shafts, a negative torque sensing system, and full beta control reversing. Complete deicing gear is also provided.