Rotorhead

Helicopter Mechanism
title: "Rotorhead" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["helicopter-components"] description: "Helicopter Mechanism" topic_path: "general/helicopter-components" source: "https://en.wikipedia.org/wiki/Rotorhead" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Helicopter Mechanism ::
::figure[src="https://upload.wikimedia.org/wikipedia/commons/4/4f/Sikorsky_S-92_rotor_P1230176.jpg" caption="The rotor head of a [[Sikorsky S-92"] ::
Types
Rotorheads can be classified into 3 main types:
- Articulated
- Semi-Rigid
- Rigid
Articulated Rotorhead
An articulated rotorhead system is one where the individual blades are free to flap, lag and change pitch. This is done by mounting the blades on flapping and lagging hinges and pitch change bearings.
Semi-Rigid
A semi-rigid rotorhead does not have individual flapping or drag hinges but provides for flapping through gimbal mounting. A common example of a semi-rigid rotor is a teetering rotorhead found on the Robinson family of helicopters.
::figure[src="https://upload.wikimedia.org/wikipedia/commons/f/fb/Robinson-Rotorhead.jpg" caption="A Robinson R22 Teetering Rotorhead"] ::
Rigid
A rigid rotorhead has no flapping or lag hinges but does have pitch change bearings. The flapping and lagging movement is accommodated by flexible sections (commonly elastomeric bearings) at the blade root or blade attachment. When using composite blades, the blades can also flex to provide a flapping motion.
Benefits of rigid rotor system are:
- Less control response lag
- Reduced maintenance
References
References
- redback. (2017-06-06). "Helicopter Rotorhead Design".
- Pallett, "Automatic Flight Control, 2nd Ed", p.55. Granada, 1983
- W.Z. Stepniewski, C.N Keys, "Rotory-Wing Aerodynamics", Dover, 1984
::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::