Understanding Propeller Torque and P-Factor: Difference between revisions

Understanding Propeller Torque and P-Factor (view source)

71 bytes removed , 22 February 2014

1

edit

@@ Line 24: / Line 24: @@
 P-factor is the term for asymmetric propeller loading, causes the airplane to yaw to the left when at high angles of attack.
-The descending right side of the propeller (as seen from the rear) has a higher angle of attack than the upward-moving blade on the left side and provides more thrust. This occurs only when the propeller is not meeting the oncoming airflow head-on, for example when an aircraft is moving down the runway at a nose-high attitude (i.e. at a high angle of attack), as is the case with tail-draggers. Aircraft with tricycle landing gear maintain a level attitude on the takeoff roll run, so there is little P-factor during takeoff roll until lift off. In all cases, though, the effect is weaker than prop wash.
+It is caused by the descending right side of the propeller (as seen from the rear) having a higher relative air flow than the ascending blade on the left side and thus providing more thrust. This would occur when the plane is climbing with a positive pitch relative to the airflow.  An extreme case of this is in the example of a helicopter flying forward.  The blade going forward has a higher relative airflow then the retreating blade and hence more lift.
-According to What You Need to Know About Aerodyanics... by Franklin Gutierrez.
+A common misconception is that the descending blade has a higher angle of attack then the ascending blade.
+The P factor effect is weaker than prop wash.
 === Gyroscopic Precession ===