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Other weight and drag saving measures included use of an all-moving ' V ' or ' Butterfly ' tail unit with two surfaces , set in a ' V ' configuration , providing stability and control in both pitch and yaw , in exchange for increased cost and complexity of the control systems and minor handling side effects , like slight pitching of the aircraft with application of rudder and vice versa .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
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