Piper Cheyenne 400LS: Outpacing the Test of Time

by Farhad Saba, Owner-Pilot

With its 351-knot max cruise speed, efficient Garrett engines, fastest climb rate in its class, FL410 service ceiling, long range and short/uniåmproved runway capability, the rare Piper Cheyenne 400LS can still outperform many turboprops and light jets in various phases of flight and missions.

Background

From 1973 to 1974 America faced an oil crisis, driving fuel prices through the roof. The Cessna Citation became the economical jet of choice for business travel. By the late 1970s, operators also turned to turboprops for even more efficient engines and better payload and range than most business jets, albeit a slower speed.

At the time, Piper Aircraft was improving on its unpressurized and pressurized piston-twin line of the Piper Navajo and Mojave. The first Piper Cheyenne was flown in 1969 by essentially hanging two PT6 turbine engines on the Mojave. The early Cheyenne’s were later refined with some aerodynamic improvements, but the PT6-28s produced only 10 to 15 percent faster cruise speed than their piston siblings and at a much higher fuel consumption. The Cheyenne could not compete with Cessna Conquest II’s top speed of 300 KTS, service ceiling of 35,000 feet and higher payload. The King Air models did not win the speed race but won big on their luxurious interiors and ramp presence.

Record Holder
With its six-pound weight to horsepower ratio, well in excess of the Extra 300 competition acrobatic plane, General Chuck Yeager set the time to climb record in the 400LS in the mid-1980s. This record is still standing after 35 years. N7222F often pleasantly surprises ATC with its initial 4,000 fpm climb rate when asked for an expedited climb. 

Piper continued to improve the Cheyenne by certifying different engines, lengthening the fuselage and adding a T-tail. The resulting aircraft included the Cheyenne I (500 SHP engine to eliminate the troublesome stick shaker), Cheyenne II  (620 SHP PT6s and a stick shaker), Cheyenne IIXL (750 SHP PT6s de-rated to 620 SHP and 18-inch longer fuselage), and Cheyenne III and IIIA (720 SHP PT6A-41s and -61s, nine seats and a T-tail).

Then, in 1984, the Cheyenne 400LS was born – the queen of the Piper Aircraft fleet.  It outperformed all turboprops and even Cessna Citations of the day with 351 KTS at 25,000 feet (or 290 KTS at 41,000 feet) on 60 gallons of Jet A/hour, and a range of 1,800-plus nm with IFR reserve. 

The Perfect Match

Today, my wife and I are the proud owners of N7222F, a 1987 PA42-1000. Ours is one of only 44 total Cheyenne 400LS models built by Piper Aircraft between 1984 and 1992. The airplane has two imposing TPE331-14 engines, each capable of producing 1,600+ SHP de-rated to 1,000 HP at its five-bladed MT propellers.

When it came time to upgrade from our Cessna 340A, our primary mission of flying from Northern Virginia to South Florida had expanded to include transcontinental and European flights (as well as a flight around the world thrown on the bucket list for good measure). Two engines being a must, I quickly honed in on two aircraft, both with the more efficient Garrett engines: the Cessna Conquest II with TPE331-10s, and the Cheyenne 400LS with TPE331-14s. Ultimately, the superior pressurization system in the 400LS (under 10,000 feet at flight level 410) was paramount in the decision-making process to safely conduct international and oceanic flights above most weather and busy traffic altitudes, along with 50 KTS faster speed available on demand. 

The previous owner of N7222F (C-FGKS) flew the aircraft from Edmonton, Canada, to Northern Virginia to show us its beauty. Upon arrival at our home airport (KJYO), it was love at first sight.

Owner Insights

A 900 nm flight from Northern Virginia to South Florida typically takes about 2 hours and 45 minutes. We cruise around 340 KTS between flight level 300 and 340, consuming 2,000 pounds of fuel for the trip. With a full fuel capacity of 3,825 pounds, a fuel load of 2,750 pounds allows an hour of IFR reserve accommodating 1,300 pounds of payload for this typical trip. This equates to six adults and 250 pounds of luggage. The 400LS is the only twin-engine turboprop that can outperform single and twin-engine civilian turbine and light jets in “door to door” speed and piston twins in efficiency for a given payload.

The Honeywell (Garrett) TPE331-14 engine and its fuel control unit are controlled by a computer for ease of operations. Full power is set for takeoff and can be maintained all the way up to altitude and cruise. Engine limiters take care of torque and temperatures with minor pilot input, if any. Engine gauges are monitored for safety. The power is reduced if leveling off below 25,000 feet to avoid over-speeding, as well as during descent and landing. The Negative Torque Sensing feature provides a level of safety similar to autofeather, reducing prop drag by approximately 80 percent in case an engine is lost immediately after takeoff. The Cheyenne 400LS is a very stable IFR platform with the control inputs on the firm side. Full Reverse allows for landing in shorter distances than even many single and piston twins.

The majority of the Cheyenne 400LS aircraft were fitted with nine seats, including a potty seat that can be completely enclosed by an accordion door neatly hidden in its furniture cabinet. The plane is easy to load through its large rear and nose baggage doors, allowing a wide range for CG. Despite the very noisy reputation of TPE331 on the ramp, passengers can comfortably carry on conversations without headsets during cruise. Up front, most remaining 400LS models have been updated with some level of glass avionics. N7222F boasts RVSM approval, ADSB-In and Out, Garmin Active Traffic, weather radar, two G600s and two GTN750s completely integrated with the original jet-level Collins APS 65 Autopilot, bringing its automation to 21st century standards. 

It’s a shame Piper stopped manufacturing the PA42-1000 in 1992 due to a continuing economic downturn, forcing most aircraft manufacturers into bankruptcy. Many aircraft including the 400LS were put to the wayside never to be manufactured again. Of the original 44 aircraft, just over 20 are believed to be flying in the United States today. A fleet of this size does not provide the manufacturer and maintenance shops enough incentives to produce parts and specialized maintenance support. The 17-foot high tail also makes finding a T-hangar at most GA airports a challenge. Today, the 400LS averages a purchase price under $1 million, with total fixed and variable hourly operating expenses of $1,500. And at 12,050 pounds MGTOW, it is approved for single-pilot operations without a type rating, although insurance companies require annual training. 

World Traveler

The Piper Cheyenne 400LS is uniquely positioned to adapt to our various missions in payload, distance and speed. Within our first year of ownership, my wife and I traveled to Bermuda, multiple Caribbean locations, and a 1,400-nm nonstop from Aspen, Colorado to Leesburg, Virginia. In October of 2019, with four occupants, we traveled through Canada, Greenland, Iceland, Ireland, Italy and back to Leesburg. The majority of the flights were flown above most airliners in comfort, style and at a fuel cost less than economy class tickets for the same itinerary. 

Although becoming an Earth-rounder has been postponed by the COVID-19 crisis, we are looking forward to completing the mission in a post-pandemic world.