King Air Modifications

Since Beechcraft's King Air is the most popular corporate turboprop ever built, with over 6,000 units delivered since 1964, it makes perfect sense that third party companies would come up with innovative modifications for most King Air models. Most of the mods enhance the performance, safety, comfort, utility or all of the above. Although all the King Air enhancements are available as aftermarket add-ons by third-party manufacturers, many of these same enhancements have been integrated into the newer models or are now installed by the factory at the time of production.

Summarized below are the many modifications for each series, along with a brief explanation. Most of these modifications have been designed by Raisbeck Engineering, a company that has built a solid reputation since 1982 for enhancing King Air performance and utility.

KA350ER/350/300 Series
PT6A-67 Engine Upgrade
Dual Aft Body Strakes
High Flotation Gear Doors
Crown Wing Lockers

KA250/B200GT/B200/200 Series
PT6A-52 or -61 Engine Upgrade
Swept Turbofan Propellers
Enhanced Performance Leading Edge
Ram Air Recovery
Dual Aft Body Strakes
High Flotation Gear Doors
Crown Wing Lockers

C90GTx/C90GTi/C90GT/C90B/C90 Series
Pt6A-135A Engine Upgrade
Swept Turbofan Propellers
Dual Aft Body Strakes
Increased Gross Weight
Crown Wing Lockers

Description of Modifications

Dual Aft Body Strakes
Two fins designed by Raisbeck Engineering that replace the single fin on the lower aft section of the tail. The modification improves directional stability and pilot control, improves passenger ride quality, reduces drag and increases yaw-damper inoperative altitudes. In most King Airs, an inoperative yaw damper will reduce the upper altitude limit that you can fly, but not with the dual aft body strakes.

Crown Wing Lockers
Streamlined storage space designed by Raisbeck Engineering installed aft of the engines. This adds baggage storage space outside the cabin. Excellent for golf clubs, skis and small surfboards.

Enhanced Performance Leading Edges
Modification designed by Raisbeck Engineering to the inboard leading edge of a King Air 200 series wing that increases climb and cruise performance, reduces stall speeds, reduces wing structural fatigue and provides more efficient air conditioning.

Winglets
Winglets designed by BLR reduce drag, to increase fuel economy, fly faster, improve takeoff and landing performance, improve climb performance, improve slow flight handling and extend range.

Frakes Stacks
Aftermarket exhaust stacks for all King Airs, designed and manufactured by Frakes Aviation. These stacks significantly reduce soot accumulation on the engine nacelles.

Garmin 1000 Avionics Upgrade
There are many avionics shops that are now installing complete Garmin 1000 Avionics Systems in King Airs. The installation can include the new GFC 700 autopilot.

High Float Landing Gear Doors
New main landing gear doors designed by Raisbeck Engineering that cover the high flotation landing gear (larger gear for unimproved runways and short fields) which increase aerodynamics and result in restoring original climb and cruise performance lost with the high flotation gear option.

Ram Air Recovery
The Raisbeck-patented Ram Air Recovery System is a modification of the engine inlet and maximizes the air to the engine inlet so that your engine retains the same power with ice vanes deployed that you get now with the ice vanes stowed. Your aircraft retains speed and power as you climb through clouds or inclement weather. With ice vanes stowed, you experience increased power and speed, and you save fuel—all at lower engine temperatures.

Swept Turbofan Propellers
These four blade propellers improve performance in all flight phases, are virtually vibration free, much quieter and have a 4,000 hour TBO over a 6 year inspection requirement.

Engine Modifications

By replacing existing engines in all three models of King Air’s you can increase climb rate, increase speed and save between $30,800 to $45,000 a year in fuel costs. Of course, none of this comes cheap, but the cost is less than a 2nd overhaul and you start life again with a new engine and warranty.

King Air C90 all models, the engines are replaced with a PT6A-135A. This gives the operator a 59% increase in climb rate, more than 270 knots of cruise speed and a single engine service ceiling of 19,000’.

King Air 200 all models, there are there choices. PT6A-42 are direct replacement engines for most B200’s. PT6A-52 engines gives the operator a 25% increase in climb, cruise speed of 311 knots and full power to FL260. PT6A-61 engines increase the climb 17% and speeds in cruise of 305 knots.

King Air 300/350 all models, the engines are replaced with the PT6A-67A, this is really a performance booster for the 350. 60% increased climb rate, 24% more power and cruise speeds of 332 knots.

Click on the 3 Blackhawk Aero XP Product Cards for a complete overview.

Check out the following links for more information and additional modifications:
www.raisbeck.com – manufacturer of modifications for King Airs
www.blraerospace.com – manufacturer of winglets for King Airs
www.blackhawk.aero – owns STC's for engine conversions for King Airs