Welcome Guest. Sign in or Signup

3 Answers

Rated rpm with throttle fully open

Asked by: 3233 views ,
General Aviation

Why is it not possible to achieve rated rpm with throttle fully open?

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.

3 Answers



  1. John D Collins on Jul 15, 2014

    For most fixed pitch propellers, there is too much air resistance to motion with full throttle and the aircraft not moving, for the engine to achieve the rated RPM. As you commence the takeoff roll, you will note that the RPM will increase and at some speed will be able to achieve the rated RPM during a static run up. A propeller pitched for best climb or one that is under sized for the aircraft might be able to achieve rated RPM during a static run up.

    For a constant speed propeller, depending on the pitch stop settings and the engine power available, it may be able to achieve rated RPM during a static run up.

    +1 Votes Thumb up 1 Votes Thumb down 0 Votes



  2. Danna danna on Jul 19, 2014

    thank you! So the aircraft can’t be on full throttle because of too much air resistance?

    0 Votes Thumb up 0 Votes Thumb down 0 Votes



  3. John D Collins on Jul 20, 2014

    Danna,

    The engine can be at full throttle, it just can’t achieve the full RPM because of the wind resistance to the motion of the propeller. RPM at full throttle without the aircraft moving is termed static RPM and usually there is a maintenance specification for what this value should be.

    +1 Votes Thumb up 1 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.