As Victor points out with the Cessna twin tip tanks, they may look cool, but they come at a pretty high cost to safety. Carrying tip tanks gives you the capability whether by accident or by mechanical failure to have the lateral balance so far out that the plane becomes uncontrollable at slow speed. Why create a safety problem when the same volume of fuel can be safely carried either in the wing stub, or the inboard section of the outer wing panel? Part of the flight testing on my KR included slow flight and landings with one wing tank full and the other empty. I designed the tank loads specifically to ensure the plane was always controllable regardless of the fuel load and configuration. Even with my wing tanks located at the inboard end of the wing panels, it doesn't take but a few gallons of imbalance for the plane to start to fly wing heavy towards the fuller side.
Additionally, while most pilots don't spin their KRs, the enertia of a load of fuel mounted at the outboard end of the wing will make spin recovery significantly more difficult. These are very real safety issues with tip tanks. Creating conditions to get you an unrecoverable spin or an uncontrollable wing heavy condition at landing speed are things that can get you killed. Jeff Scott Los Alamos, NM
