This video alone made me subscribe. Thank you for the educational content on helis. There are barely any helicopter channels on the platform. You're now on my go-to list along with another awesome channel called Helicopter Lessons in 10 Minutes or Less.
The description of blade coning angle in this video is quite correct, but it is only true for rotor heads that have flapping hinges. Early helicopters had blades made of wood, and later with an extruded aluminium spar with bonded ribs and pockets to form the aerodynamic profile. These blades would be subject to bending stresses that could lead to catastrophic failure, so the addition of a flapping hinge allowed the blade to flap up, until the vector addition of the centrifugal and lift forces resulted in a single force that acted along the length of the blade. This removed the bending stresses. The problem with flapping , drag and pitch change hinges in a “fully articulated” rote head is that the bearings operate continuously over a small arc of movement, causing wear, which results in vibration. Frequent overhaul of the rotor head is required to replace the bearings, resulting in considerable cost per flying hour. Modern designs and materials for both the rotor head and blades means that some rotor heads do not have any rotating bearings. The material construction of the blades means that they are strong enough to withstand the bending stresses, and in order to achieve directional thrust from the rotor disc as well as vertical lift, in the absence of flapping hinges, the blades are required to bend slightly. Examples are the AW109 and the Merlin. The MBB 105 has a fully rigid rotor head with only pitch change bearings. The Lynx family has a semi rigid rotor head also with pitch change bearings.
I have always wondered if span-wise flow was controlled in rotor blades. I thought that controlling span-wise flow across the rotor would create more efficient lift of rotors for the same size. I don't see fences or winglets. Need to talk to a rotor aerodynamics guy.
Hi Shazrul, I am glad you liked the video! You can read more about helicopter blade coning if you go to page 2-16 in FAA's Helicopter Flying Handbook. You can get a copy for free on the FAA's website.
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Perfect video. Short and effective…Please continue making videos like this
This video alone made me subscribe. Thank you for the educational content on helis. There are barely any helicopter channels on the platform. You're now on my go-to list along with another awesome channel called Helicopter Lessons in 10 Minutes or Less.
The description of blade coning angle in this video is quite correct, but it is only true for rotor heads that have flapping hinges. Early helicopters had blades made of wood, and later with an extruded aluminium spar with bonded ribs and pockets to form the aerodynamic profile. These blades would be subject to bending stresses that could lead to catastrophic failure, so the addition of a flapping hinge allowed the blade to flap up, until the vector addition of the centrifugal and lift forces resulted in a single force that acted along the length of the blade. This removed the bending stresses. The problem with flapping , drag and pitch change hinges in a “fully articulated” rote head is that the bearings operate continuously over a small arc of movement, causing wear, which results in vibration. Frequent overhaul of the rotor head is required to replace the bearings, resulting in considerable cost per flying hour. Modern designs and materials for both the rotor head and blades means that some rotor heads do not have any rotating bearings. The material construction of the blades means that they are strong enough to withstand the bending stresses, and in order to achieve directional thrust from the rotor disc as well as vertical lift, in the absence of flapping hinges, the blades are required to bend slightly. Examples are the AW109 and the Merlin. The MBB 105 has a fully rigid rotor head with only pitch change bearings. The Lynx family has a semi rigid rotor head also with pitch change bearings.
You have answered my 7 months dilemma in 1:51 time. Thanks🙏
Great video lesson. Thank you.
I have always wondered if span-wise flow was controlled in rotor blades. I thought that controlling span-wise flow across the rotor would create more efficient lift of rotors for the same size. I don't see fences or winglets.
Need to talk to a rotor aerodynamics guy.
Amazing content
once again thanks
Nice to see the lesson..... Plz give something about transverse flow effect, vortex ring, LTE and blade stall. Thank you.
I'm glad you enjoyed the video! All those subjects are covered in the online ground school over at flight-first.com
Thanks
Thanks 🙏
hello. nice explanation from you. may i know which book do you refer? i want to buy it as my reference book
Hi Shazrul, I am glad you liked the video! You can read more about helicopter blade coning if you go to page 2-16 in FAA's Helicopter Flying Handbook. You can get a copy for free on the FAA's website.
Outstanding job! #SkyBaum
Thanks 🙏