Left-turn tendencies

Dazzler

Dazzler

Well-Known Member
Generally speaking, would it be true to state that, for single engine fixed-pitch propeller aircraft, left-turn tendencies are at their greatest at:
- High RPMs
- High angle of attack
- Low airspeed?
 
Dazzler said:
Generally speaking, would it be true to state that, for single engine fixed-pitch propeller aircraft, left-turn tendencies are at their greatest at:
- High RPMs
- High angle of attack
- Low airspeed?
Click to expand...

Yes. P-factor is most pronounced at high angles of attack because this is the time when the angle of attack of the descending blade is greater than the angle of attack of the ascending blade.

At higher RPM's you have more torque and also the P-factor phenomena is occurring more times per minute.

The actual FORCES of the left turning tendencies does not vary with airspeed only on power setting and angle of attack (however at high angles of attack your airspeed isn't going to be exactly pushing the barber pole). However your ability to counter the left turning tendences IS dependent on airspeed in the form of rudder effectiveness.

I've never seen this specifically mentioned but I'll venture to guess that this holds true for constant speed props and multi's (non-counter-rotating) as well.
 
Dazzler said:
Generally speaking, would it be true to state that, for single engine fixed-pitch propeller aircraft, left-turn tendencies are at their greatest at:
- High RPMs
- High angle of attack
- Low airspeed?
Click to expand...
Specifically speaking, the greatest left-turning tendency is at full power at highest angle of attack at lowest airspeed before stalling. This moment would require the greatest right-rudder input to hold a constant heading.
It is almost full right rudder with the relatively new small rudder designed airplanes.
 
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