M12.01 Theory Of Flight Flashcards
(18 cards)
What is pitch angle
Angle between the plane of rotation and the chord line
What is relative airflow always opposite to
The blade flight path
Do advancing blades produce more or less lift than retreating blades?
More
The centre of pressure is where ?
Lift and drag act
Gyroscopic procession is?
Where the pilots input would be 90 degrees
Types of anti-Torque systems (7)
Main and tail
Fenestron
Notar
Edat
Twin-rotor
Co-axial rotor
Intermeshed rotor
What effect does the NOTAR use
Coanda effect
What is dissymmetry of lift
Advancing blades produce more lift than retreating
Dissymmetry of lift is counteracted by?
Allowing blades to flap
Translating tendencies is?
When the heli drifts in the direction of the tail rotor
Translating tenancy is corrected by ?
Either mounting the transmission at an angle or rigging flight controls to a tilted position
How do you correct the Coriolis effect (in 3 or more blade helis)?
Lead-lag hinges (dampers)
In two blade helis how do you correct for Coriolis effect?
They use a teetering head
What is vortex ring state
Where tip vortexes rotate round the tip and re enter the down wash
Over pitching is?
When the pilot increase the collective too quick and engines can’t keep up
What do anticipators do ?
Up engine rpm when collective is raised
What is auto-rotation
When engines fail and as heli falls through the air and blades spin producing lift
Ground effect ?
A cushion that forms half a rotor blade bellow the helicopter that it sits on while in hover
