Welcome Guest. Sign in or Signup

2 Answers

How Does Pitch Affect Fixed-Pitch Propeller RPM?

Asked by: 5528 views , ,
Aerodynamics, Aircraft Systems

Does a fixed-pitch prop's RPM change with pitch and given throttle setting? Does it spin faster because of the windmill effect or spin slower due to the load that is being placed on it?

Ace Any FAA Written Test!
Actual FAA Questions / Free Lifetime Updates
The best explanations in the business
Fast, efficient study.
Pass Your Checkride With Confidence!
FAA Practical Test prep that reflects actual checkrides.
Any checkride: Airplane, Helicopter, Glider, etc.
Written and maintained by actual pilot examiners and master CFIs.
The World's Most Trusted eLogbook
Be Organized, Current, Professional, and Safe.
Highly customizable - for student pilots through pros.
Free Transition Service for users of other eLogs.
Our sincere thanks to pilots such as yourself who support AskACFI while helping themselves by using the awesome PC, Mac, iPhone/iPad, and Android aviation apps of our sponsors.

2 Answers



  1. Mark Kolber on Dec 16, 2014

    I’m going to take a stab at answering what I think this is asking.

    A propeller is an airfoil. It is really just another lifting surface like the wings. A fixed pitch prop is fixed with respect to the aircraft just as the wings are (angle of incidence). And just like the other airfoils on the airplane, its pitch with respect to the relative wind – angle of attack – can changed based on the airplane’s attitude. With a resulting change in RPM.

    The most common example of this is one you can see every time you fly. Set the power for 2400 RPM in cruise. If you don’t touch the throttle, RPM will decrease when you climb and increase when you descend due to your changes in pitch attitude.

    0 Votes Thumb up 1 Votes Thumb down 1 Votes



  2. Drew on Dec 17, 2014

    Thanks for the response. That does make sense. I’ve reworded the question to say what I mean. So a greater AoA produces more lift, which in turn slows the RPM. I assume it’s the increased induced drag of the prop that counteracts the RPM, since the propeller is just like a wing.

    0 Votes Thumb up 0 Votes Thumb down 0 Votes


The following terms have been auto-detected the question above and any answers or discussion provided. Click on a term to see its definition from the Dauntless Aviation JargonBuster Glossary.

Answer Question

Our sincere thanks to all who contribute constructively to this forum in answering flight training questions. If you are a flight instructor or represent a flight school / FBO offering flight instruction, you are welcome to include links to your site and related contact information as it pertains to offering local flight instruction in a specific geographic area. Additionally, direct links to FAA and related official government sources of information are welcome. However we thank you for your understanding that links to other sites or text that may be construed as explicit or implicit advertising of other business, sites, or goods/services are not permitted even if such links nominally are relevant to the question asked.