Welcome Guest. Sign in or Signup

2 Answers

How is torque measured in Bell 204/205 helicopters?

Asked by: 3939 views ,
Aircraft Systems, Helicopter

Is the torque measured based off oil pressure?

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. Nibake on Jan 21, 2016

    This is going to be a crude answer.

    If this is a turbine powered helicopter I can tell you how torque is measured in a PT-6 and that may help you. It is not engine oil pressure. In the gear reduction there is a helical gear. Because the gears are ‘slanted’ with relation to each the more force applied to the driven gear the more it is forced back. Oil behind that driven gear resists this. The oil pressure resulting from that force applied to the driven gear is used to measure torque. Hope this helps. Maybe someone else can give you a more advanced description.

    0 Votes Thumb up 0 Votes Thumb down 0 Votes



  2. Abner on Mar 19, 2017

    It is gearbox oil pressure. Inside the reduction gearbox is a helical style gear that is able to “float” and move about it’s axis with changes in power/torque. This movement pushes oil in and out through an orifice and the torque is measured. The oil line in older helicopters may go straight to the gage in the cockpit, or has a transducer on the gearbox itself which turns the oil pressure measurement to an electrical signal to the gage.

    The newer technology aircraft measure torque through shaft twist/torsion and separation with a phonetic type sensor that then sends the signal.

    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.