September 1, 2012
Robert C. Searles
The Piper Cheyenne I (PA–31T-1-500) and Cheyenne IA (PA–31T-1A-500) are successor versions to the twin-turboprop Cheyenne II. The Cheyenne I/IA designation can be confusing, because the first Cheyenne models to be brought to market were renamed Cheyenne IIs after the I and IA were rolled out. So the II came out first, in 1974, but the I/IAs came out later, and were produced from 1978 to 1984. The main difference between the II and I/IA is engine power. The 277-knot Cheyenne IIs come with 620-shp Pratt & Whitney PT6A-28 engines; the I and IA have 500-shp Pratt & Whitney PT6A-11 engines and so have lower max cruise speeds. The II’s extra power proved to have a destabilizing tendency in high-power, low-airspeed regimes, so the II and IIXL were fitted with a stability augmentation system to eliminate any potentially dangerous pitch responses. The Cheyenne I/IAs don’t require stability augmentation.
The Cheyenne IA, which earned FAA approval in May 1983, offered redesigned engine cowlings and exhaust stubs, yielding 4 percent more horsepower at high altitudes, and improved cruise speed to 261 knots. Standard fuel capacity is 308 gallons; optional tip tanks bring it to 390 gallons.
Aftermarket enhancements for the Cheyenne I series include engine conversions from Blackhawk Modifications of Waco, Texas. The XP28 package replaced the twin turboprop’s original 500-shp PT6A-11 engines with 620-shp PT6A-28 powerplants flat-rated to 500 shp. Performance improvements include greater climb rates; less time, distance, and fuel to climb; and 25-knot-faster cruise speeds. Including four-blade Hartzell or McCauley propellers is an option. Blackhawk also can install 750-shp PT6A-135A powerplants, which enables retrofitted Cheyenne Is to achieve max cruise speeds of 280 knots while reducing time to climb and extending range.
A total of 215 Cheyenne I and IAs were built, and 143 remain on the FAA registry. Current Vref prices for the aircraft range from $340,000 for a 1978 Cheyenne I to $470,000 for a 1984 Cheyenne IA. Some aircraft that have been updated with Avidyne or Garmin avionics have higher asking prices.
Robert C. Searles is a writer and editor specializing in commercial, military, and general aviation.
Cheyenne I Specifications
Cheyenne IA Specifications
As the cold weather chills AOPA’s Headquarters in Frederick, many of us are inside generating new resources for flying clubs.
In my house, every Friday night is “Movie Night.” While the movies are rarely educational (I don’t think I learned anything from the Lego Movie), we look forward to the weekly opportunity to spend time together. Why not use the same concept for your Flying Club (with the addition of education, of course)?
AOPA Flying Club Manager Kelby Ferwerda posted the following on the AOPA Flying Club Facebook Page: “Recently I’ve talked with quite a few Flying Clubs about maintaining social activity through the cold winter months. Some clubs host Holliday Parties, others have Potluck Movie Nights. What does your club do to keep members involved during the chilly months?”
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