Summary of drag clean-up tests in NASA Langley full-scale tunnel

This summary of drag results presents tabulations on fighter aircraft and light twin general aviation aircraft wind tunnel tests. The figures show that the friction drag for light twins is larger than that for the fighters because of the greater wetted area and the smaller wing area used for reference. Full scale tunnel tests developed the following design features contributing to excessive drag: cooling flow system, engine exhaust stacks, landing gears, control surface gaps, and wing irregularities and leakages.