Helicopter Physics Series - #3 Upside Down Flying With High Speed Video - Smarter Every Day 47

• Collective pitch control for helicopters • Cyclic pitch control for helicopters • Anti-torque pitch control

Combining collective and cyclic controls to describe collective-cyclic pitch mixing, which is how every helicopter pilot flies.

Using high-speed video footage of Carl flying an RC helicopter to illustrate the concepts.

Pilots must use both collective and cyclic inputs simultaneously, constantly varying both controls rather than using one particular input alone.

Carl performs an inverted flight by flipping the helicopter over while controlling its movement.

• Uses collective to make the sweep go up • Returns to negative collective to invert • Continuously balances with cyclic adjustments

The maneuver demonstrates that helicopter control requires simultaneous adjustment of multiple inputs rather than discrete, separate commands.

High-speed video captures the precise coordination required, making the dynamic control inputs visible.

Carl mounted a camera on the back of the helicopter looking at the swashplate during normal flight to visualize collective-cyclic mixing in action.

• Rotors may appear to be bending in the footage • This is a camera artifact, not actual rotor deformation • Caused by the rolling shutter of the camera sensor

• Rotor shaft appears to speed up and slow down wildly • Related to the frame rate of the camera • A phenomenon called aliasing

Understanding these optical effects helps interpret the video footage accurately while focusing on the actual swashplate movements beneath them.

• Full-size helicopters can perform these maneuvers if designed for it • Limitations exist due to human tolerance for acceleration • Pilots experience physical constraints that RC pilots do not

Engineers use a term called similitude to understand how to scale RC helicopter maneuvers up to real-world helicopters, involving geometric, kinematic, and dynamic similarity.

Similitude relates to continuum mechanics, a discipline used by aerospace engineers in applications like space shuttle wind tunnel testing.

• Next week's video will cover complex but interesting helicopter physics • Personal connection to Destin, Florida and its thrift stores • Encourages viewers to continue learning and getting smarter