Prop Blade Effects

We often treat the propeller as a uniform “actuator disc” and the slipstream as a uniform stream tube of accelerated and swirling air. While...

Torque and P-factor

We’ve touched on this during previous discussions of slipstream (most recently in the April 2023 issue), but there are several power and propeller effects...

Thrust Line Effects

The propeller of an airplane generates thrust that drives it through the air. In addition to propelling the airplane, the thrust of the propeller...

Propeller Effects–Lateral Directional

The propeller slipstream affects the aerodynamics of the airplane. A propeller accelerates air backward and also imparts a swirl. The air in the slipstream...

Design Process: Slipstream Effects

In preliminary design and for performance calculations, we treat the engine, propeller and airframe as separate entities. The only engine effect we typically consider...

Design Process: Engine Size

The engine of an airplane must produce enough power to meet the requirements of all phases of the mission. First, the engine must accelerate the...

Design Process: Strakes and Ventral Fins

On some airplanes, the basic empennage does not provide acceptable flying qualities in all flight regimes. Supplemental surfaces to augment directional stability, improve high...

H-tails and Triple Tails

The majority of airplanes use the conventional tail configuration with a single, centrally mounted vertical tail and rudder. Sometimes, however, the vertical tail is...

Design Process: T-Tails

A T-tail is a configuration where the horizontal tail is mounted on top of the vertical tail rather than directly to the fuselage. T-tails...

Design Process: V-Tails

A V-tail is a configuration where the horizontal stabilizer and vertical fin are replaced by a pair of surfaces mounted at a high dihedral...

In Case You Missed it

Flaperons, Spoilers and Drooping Ailerons

There are some situations where there isn’t enough room on the wing’s trailing edge...

Turbine Temptation: Wiring, Avionics and Plumbing

The systems are simple but space is tight, so plan ahead.

Wind Tunnel

Seemingly inconsequential alterations—even mounting an inflight camera on the airframe—can result in big changes to an aircraft’s handling and performance.