Intercontinental Jet Corporation demonstrated its upgraded MU-2 at NBAA last month. The company has completed an STC to upgrade the powerplants on models J,K,L and M of the twin turboprop with AlliedSignal TPE331-10 engines. The upgraded aircraft produced true airspeeds of 295 to 310 kt at heights of between 14,500 and 21,000 feet. This performance is around 35 kt faster than with the original -6 engines, according to Inter-continental Jet. \rThe company also claimed to have achieved mid-weight climb to 20,000 feet in an average of 10 minutes with the -10AV engines. They offer "a significant increase in thermodynamic horsepower rating - 1,000 shp versus 840 shp in the -6," said Intercontinental Jet.\rAlliedSignal offers two options for customers wishing to upgrade their MU-2s. The modification can be a straight conversion from the -6 engines, or completely overhauled engines can be installed. In either case, the work is conducted and warranted by AlliedSignal in Phoenix.\rFor operators whose engines have a significant amount of time remaining before overhaul, Intercontinental Jet recommends the "continued time" option, a straight conversion of the customers -6 engine and no change in the TBO of 5,400 hours. The cost of this is $278,000, not including the necessary installation of Hartzell propellers with improved short-peened blades to handle the torque of the -10s. These blades cost approximately $30,000. At least 35 days downtime is required\rAircraft with engines which are at or near TBO can opt for the full overhaul, which results in engines being converted to zero time. Under this option, operators may choose to run their "new" engines on a 5,000 hour TBO with one mid-life hot-section inspection due at 2,500 hours. Or, they may elect a 5,400 hour TBO with one hot-section inspection at 1,800 hours and another at 3,600 hours. The cost of the complete overhaul is $408,000 and requires seven days downtime.