Page 4 - Volume 12 Number 8

The Fastest King Air: Blackhawk’s XP67A 350
The Pratt & Whitney Canada PT6A-67A turbo- propeller engine. That’s a mouthful! However, for an experienced King Air pilot, the various versions of the iconic PT6 powerplant roll off the tongue with ease. Memorizing which version they operate and the shaft horsepower (SHP) and equivalent SHP (ESHP) ratings of it are mandatory for King Air pilots. Not only is such information sure to be asked during the oral exam portion of any checkride, it is also one of the first conversation points between various King Air pilots crossing paths at airports. For years, the most powerful PT6 version used on King Airs has been the -60A model used on the Super King Air 300/350 series. However, thanks to one of the leading companies in turboprop aircraft modification and performance enhancements, Beechcraft’s famous family of rugged turboprops has a new ruling monarch. Meet the fastest King Air in the world – the Blackhawk XP67A 350.
A Quick Look Back
While detailing the long history of the King Air isn’t necessary for readers of King Air magazine, a quick reminder of how the 300/350 came to be might be in order. The first King Air was flown in 1964 and exactly one decade later the first production model Super King Air 200 was delivered. Fast forward another decade and the success of the 200-series spawned the Super King Air 300. First delivered in 1984, the 300 was the first model to utilize the PT6A-60A, which has retained the same 1,050 SHP rating on every production 300/350 model since. The 300 was also the first model to exceed 12,500 lb. Maximum Gross Weight (MGW), making it the first King Air to require its Pilot in Command (PIC) to hold a specific type rating. In 1990, the 300’s fuselage was stretched 3 feet, winglets were added and MGW increased to 15,000 lbs. to create the B300 model (more commonly referred to as the Super King Air 350). Today, two variants of the 350 remain in production,
2 • KING AIR MAGAZINE
Blackhawk Sales Manager Chris Dunkin departs Gwinner, North Dakota’s (GWR) runway 16 on a hot and blustery June day.
the 350i and the 350ER. However, the moniker “Super” was dropped from all King Air marketing materials in 1996. Blackhawk Modifications is an after-market company, founded in 1999. Based in Waco, Texas, they have become a star player in the turboprop enhancement market. While they offer a number of upgrades for various King Air models, they also offer similar modifications for a wide variety of other turboprop aircraft (both single and twin engine). In fact, as the holder of the most STCs for such aircraft, they’ve become the largest non-OEM purchaser of PT6 engines in the world. Blackhawk calls their turnkey performance packages XP Engine+ Upgrades. It is such a package they successfully certified in August 2017 for the King Air 350 line with about a
dozen installations completed so far.
10 Gallons of Engine in a Nine-Gallon Cowl
No transport category aircraft modification program is ever as simple as it may seem. Minor modifications can quickly cascade into a series of required changes. The swap of the -60A engine for the -67A seems straightforward to the casual observer. Until you learn that the -60A was already a tight squeeze within the KA 350 cowlings and that the -67A is three-plus inches longer still! So, how do you install a longer engine without setting off an avalanche of other changes? Blackhawk’s solution is elegant in its simplicity. The -67A engine was mounted so that the prop is in nearly the same position (relative to the wing’s leading edge and C.G.), as that of the -60A. This prevented any negative changes in handling, controllability, or weight and balance (W&B). But, this caused the engine’s air intake (which is at the rear of the PT6’s reverse-airflow design) to extend aft of the existing cowl’s sealed air intake section. The solution: Blackhawk designed and manufactured an extension to move the cowl’s interior air
by Matthew McDaniel
AUGUST 2018