Page 13 - Volume 20 Number 8

Once the first engine’s generator comes on to restore battery condition, the second engine follows in due course at low idle. Avionics up, it’s time to taxi. Nosegear steering is positive and beta range holds taxi speed down to spare the brakes. Pretakeoff checks include the normal governors testing at 1,600 rpm, a flap-comparison test button is pushed, and there’s a “q-system” test, a simple sensor that inhibits gear retraction and pressurization engaging until 100 knots airspeed is reached. Yaw damper and prop synchrophasing are off and the oil cooler doors are open.In position, torque is brought up to achieve prop governing at 2,000 rpm, then brakes are released to feed in 1,800 ft/lbs torque, building to 1,900 on the roll. Rotation is initiated at 105 knots, slightly above the Vmc of 97 knots, and Vyse is in hand at 115 knots. Gear retraction is to be done prior to 151 knots; best rate of climb comes at a verysteep 118 knots, so most climbs are done at 160 knots, with prop rpm tweaked back to 1,900 or 1,800. Climb rate initially was 1,600 fpm at 130 knots, with a takeoff weight of about 10,700 pounds.Climb rate out of 21,000 feet was still 1,100 fpm, where the torque had faded to 1,550 pounds. Leveled at FL250, torque was down to 1,400 pounds with the props pulled back to 1,700 rpm for even quieter operation; the IAS built to 172 knots, for a TAS of 265, using 270 pph of fuel per side. The cabin held at a comfortable 6,500 feet. Thanks to the 30-inches farther outboard engine location, the noise level was much lower than in the smaller Cheyennes. In fact, it was so quiet we eschewed headsets when we tried out the cabin environment; the prop and wind noise was a gentle hum.The day’s trip was a 422 n.mi. run to Chicago Executive airport at Prospect Heights, Illinois, and witha 100-knot tailwind the scenery passed quickly. Layered conditions required the RNAV 16 approach at PWK, but the venerable automatic flight control system coupled nicely and we were soon maneuvering straight-in at 130 knots. The first 10-degrees of flap can be extended at 195 knots and gear can go out at 173 knots, so the Cheyenne III can keep up with fast traffic. Additional flaps are allowed below 151 knots. Shooting for 111 knots on short final, the landing was smooth and turnoff came in 3,000 feet.In general, we found the CheyenneIII to be a very capable performerand much easier to fly than thesmaller PA-31 derivatives, thanksto its long fuselage and large tail.It’s honest and straightforward,ready to do a good job in the middleits stride. T&T •altitudes. It’s too bad the marketcollapse came as it was just hittingAUGUST 2016TWIN & TURBINE • 11