Page 7 - Volume 18 Number 10

Cheyennes by LeRoy Cookthe Cheyenne II in 1978, when the lighter Cheyenne I with 500-shp -11 engines was introduced, and the two-foot longer Cheyenne II XL, using 620-shp -135 engines, was introduced in 1981. The T-tail PA-42 Cheyenne III and IV were entirely different airplanes.The Liberal FleetLyddon Aero’s Steve Lyddon filled us in on his company’s experience with the Cheyennes. The company operates a Cheyenne I, fitted with the optional wingtip fuel tanks, and a Cheyenne II XL. The XL offers better altitude performance and, of course, extra space for the passengers. Trip lengths are typically 300 to 500 miles, although there is an occasional East Coast or West Coast trip. “Four hours is a long time to sit for most people”, Lyddon says, “but it can be done.” The XL can carry full fuel and 1,200 pounds in the cabin, about six people, while the Cheyenne I can haul its 2,450 pounds of fuel and four passengers.Operationally, the Cheyenne II XL works well at FL260, perhaps FL280, while the Cheyenne I is happiest around FL220 and FL240. Certificated operational limits are 31,000 feet for the XL, 29,000 feet for the I. “It’s about like comparing the King Air 90 series and the 200 series,” says Steve Lyddon. Because the XL has a propensity toward nose-heaviness, with its two-foot fuselage stretch, it should be loaded from back to front, while the short- body Cheyenne I is loaded in a front- to-back order. If the I’s seventh seat is occupied, ballast will be needed in the nose compartment. Neither of the follow-on models needed the original Cheyenne’s SAS device.Lyddon’s Cheyennes fly about 450 hours per year. They are owned in partnership with local individuals who use the airplane for business and personal flying, sharing the hours and splitting the fixed expenses as a ratio of ownership. “We hold back $300 per flight hour for maintenance reserve on the XL,” Lyddon said, “and $250 per hour on the Cheyenne I.” Most of the maintenance can be handled locally, because Lyddon’s shop is well-acquainted with the airplanes from servicing the half- dozen on the field.Walk-around InspectionSystemswise, the Cheyenne benefits from Piper’s simple approach to engineering. The gear is operated by dual hydraulic pumps, with both a hand pump and nitrogen-charged blow-down bottles for backup. The maingear tires are 6.50 x 10 units and the nosegear tire is either an 18 x 4.4 standard unit or a 17.5 x 6.25 high-flotation tire. The gearmay be extended below 153 knots, with a 139-knot retraction limit. The maingear stows away cleanly behind sequencing inboard wheel well doors.The flap system is electrically- actuated, selectable in increments up to 40 degrees. The system is monitored for asymmetry and will shut down if extension differs by more than 5 degrees. Approach flaps (15 degrees) can go out at 181 knots, with full flaps permitted below 148 knots.The Cheyenne’s speed is enhanced by a relatively-narrow fuselage and the pencil-slim nacelles. A ladder is required to check the oil through an access door atop the nacelles.The fuel system consists of a series of interconnected tanks, two bladders and a nacelle tank on each side plus a tip tank. The system is initially filled through the nacelle-tank ports, giving 338 gallons (300 gallons in the Cheyenne I), after which the tip tanks may be filled to reach 382 gallons. No management is required unless crossfeed is desired.The Cheyenne nose section holds, from front to back, the radar unit, a NiCad or lead-acid battery, baggage and avionics, with environmentals in the lower portion. The XL uses a bleed- air powered air-cycle system, while the Cheyenne I has a combustion heater and an electrically-driven air conditioner. The nose baggage compartment, reached through a left-side door, holds 300 pounds and the aft-cabin baggage area takes 200 pounds. To facilitate loading the rear cabin’s baggage hold, an optional swing-up cargo door aft of the airstair door was available to provide a 45-inch wide opening.OCTOBER 2014TWIN & TURBINE • 5