servo control

noun

: an auxiliary aeronautical device to reinforce by an aerodynamic or mechanical relay a pilot's effort in operating a control commonly consisting of a small hinged auxiliary airfoil at the trailing edge of an aileron, elevator, or rudder

called also Flettner control

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!