The winglets were developed by Learjet in the 1970's. The early Learjets had
almost straight wings. They were looking as swept wings as a means of
increasing their efficient high mach cruise numbers.
Swept wings at high speeds tend to have the air turn and slide down the wing
instead of flowing straight over it. This is why there were spill fences and
other gadgets tried to reduce this. The winglets did a good job: the air
tended to straighten out somewhat. It provided more airflow over the ailerons
at high angles of attack, which improved low speed aileron authority.
An additional benefit that they had not anticipated was that it improved the
directional stability. If the aircraft yawed, the side loads on the winglets
would return it to neutral.
I doubt if there would be any measurable benefit to add winglets to KR, but
they sure look sexy!!!
Jim Vance
va...@claflinwildcats.com
