Carat (mass) quarters" of 15 grains troy each. Likewise, the ounce troy was divisible into 24 "ounce carats" of 20 grains troy each; the ounce carat was divisible into four "ounce grains" of 5 grains troy each; and the ounce grain was divisible into four "ounce quarters" of grains troy each. The "solidus" was also a Roman weight unit. There is literary evidence that the weight of 72 coins of the type called "solidus" was exactly 1 Roman pound, and that the weight of 1 "solidus" was 24 "siliquae". The weight of a Roman pound is generally believed to have been 327.45
AMS-Flight Carat feather the propeller blades. The Carat's propeller is opened by the centrifugal force on the turning blades, working against a folding force provided by a gas damping spring mechanism. This folding mechanism has the advantage of simplicity, but it means that the engine can not be windmill-started if the battery is flat. Because of the forward pointing blades when the engine is off, the Carat cannot be towed aloft like traditional sailplanes. The first flight was made on 16 December 1997 and the first production model displayed at Aero '99 at Friedrichshafen in April 1999 as the Technoflug TFK-2 Carat.