Blackhawk Aerospace has received STC approval from the FAA for a new XR Upgrade Kit for the King Air 350 series.

The kit optimises a standard King Air 350 series aircraft by increasing Max Gross Takeoff Weight to 16,500 pounds and maintaining a Basic Aircraft Empty Weight that is 220 pounds lighter than comparable extended range aircraft for greater payloads and up to 25 per cent more endurance.

The original P&W PT6A-60A engines and four-bladed aluminum propellers are removed and replaced with 1,200 shaft horsepower (SHP) PT6A-67A engines and lightweight MT five-bladed composite propellers. The XR Upgrade Kit also includes new heavy-weight landing gear, high flotation tires, Raisbeck fully enclosed high flotation gear doors, and the True Blue Power TB44 lithium-ion battery. The XR kit also incorporates conformal auxiliary CenTex saddle tanks that are 172 pounds lighter than the OEM's extra range fuel tanks while providing additional endurance and range improvements to meet the most demanding mission requirements.

“We've been providing aftermarket improvements to general and business aviation aircraft for over 20 years and we're honoured to expand our offerings into the government, military and special mission arenas,” comments Jim Allmon, Blackhawk Aerospace president and CEO. “The XR conversion will transform a standard King Air 350 into an extended range aircraft and will help our service members operating in the harshest environments complete their mission safely, on time and under budget with a far more capable aircraft.”

The PT6A-67A 1,200 SHP engines provided with the XR kit are flat rated to 1,050 SHP. The -67A's larger compressor produces higher thermodynamic horsepower output to provide full torque at higher altitudes. This extra horsepower provides improved first, second and third segment climb capability, greater takeoff performance in high and hot conditions, and increased single-engine service ceilings. The ability to reach FL350 in 18 minutes significantly reduces exposure within hostile airspace and ensures crews can be on-station to meet time-critical mission execution windows. A larger, single oil cooler is provided with each engine to ensure oil temperatures remain within limits while taxiing during the hottest weather conditions. The new PT6A-67A engines come with a P&WC enhanced warranty of 2,500 hours or five years with prorated coverage to the 3,600 time before overhaul (TBO) and include all mandatory and optional service bulletins. The new engines deliver peace of mind and greater reliability while significantly expanding mission capabilities.

The quieter MT five-blade composite propellers offer an optimised blade design and shorter diameter (102 inches) to increase ground clearance and reduce foreign object damage (FOD). The composite blades reduce cabin and exterior noise by at least five dBA helping to improve stealth operations. Another key advantage of the MT propeller is that it allows for the removal of the ground-idle solenoid, which reduces weight and maintenance costs. The composite propellers are extremely durable and come with the longest TBO in the industry at 4,500 hours. They also offer unlimited blade life compared to traditional aluminum propellers, which can only survive to the third or fourth overhaul.

The True Blue Power TB44 Lithium-ion battery replaces the main-ship battery, which provides a weight savings of 30 pounds while doubling cranking amps for quicker engine starts. This battery is built for use under the toughest conditions with superior temperature performance while having a useful life that is double that of lead-acid and NiCad alternatives. The intelligent monitoring system incorporated into each True Blue Power battery prevents the need for battery removal for capacity checks and reduces maintenance costs by 50 per cent or more.

The XR-equipped King Air 350 with PT6A-67A engines requires 4.8 per cent less power at equal speed and produces 24 per cent more horsepower at typical loiter altitudes, which delivers up to 25 per cent more endurance than a PT6A-60A-equipped King Air 350. Furthermore, Blackhawk's XR kit significantly expands the ability to meet or exceed second segment climb gradient requirements with full fuel and provides a head-turning 60 per cent increased climb rate to altitude. The XR kit also increases cruise speeds 30-40 kts to ensure on-time mission execution with minimal notification.

In addition to performance enhancements, the XR Upgrade Kit also impacts the bottom line. The kit provides improved performance and operational flexibility at a significantly lower acquisition cost as compared to other special mission aircraft with extend range. Factory-new propellers, engines, heavy weight landing gear, True Blue lithium-ion battery, Raisbeck fully enclosed high flotation gear doors and CenTex saddle tank fuel lockers are all included in the price of the upgrade.