[Music] [Music] [Music] [Applause] welcome back the helicopter lessons in ten minutes or less I'm Jacob and this episode covers dynamic rollover so let's get to it now dynamic roller is roll over is the point at which a helicopter will continue to roll over despite pilot inputs but Before we jump into dynamic rollover it's important to understand what is static rollover now static rollover is just that it's the point at which an object will roll over from a static or stationary position pretty much means any object where the center of gravity is above the ground something like a table or a chair or car or helicopter now it requires a pivot point and a critical angle so let's take a look at what that means now I said earlier this can apply to anything right so let's say I'm in my my dining room and I want to move my dining room table now as soon as I pick up the the dining room table it's gonna have a center of gravity one sits above the ground and let's say I just begin to push on the dining room table in this this direction well at this point I have a pivot point it's a point where the object pivots and have a center of gravity which is like I said above it sits higher on the object as it is above the ground now as I push on this object it's going to get to the point where the center of gravity is going to be above this pivot point and that will be exceeding the critical angle now what does that mean the critical angle is just it's nothing more than the angle that determines which way an object will fall or roll so at this point if the center of Graham center of gravity is on this side of the the pivot point if I were to release the object it would continue to fall to the left if this centre of gravity would pass on this side of the pivot point the object would fall to the right all right so in this situation right here we have a pivot point and we have an exceeding of the critical angle and that makes up makes up a static rollover condition now let's apply this to a helicopter let's say we have a helicopter right here I say it's parked on the ground and engines are off what not and all of a sudden somebody just comes out there and wants to push on this helicopter now at the center of gravity definitely gonna be higher in helicopters than it is and some other objects because of our transmission or drivetrain rotor system engines all that tends to sit higher so that center of gravity is naturally going to be higher in a helicopter but there's going to be a point at which that center of gravity is going to be above the pivot point and the aircraft is going to want to roll and that is that critical angle now let's say for just simplicity in this example maybe that's 15 degrees there's a point at which say 15 degrees I pushed this helicopter and it will just continue to fall to the right and set up to the left once it exceeds that critical angle all right once again it's got that pivot point let's say this main landing gear and it's exceeded the critical angle it continues to fall over an aesthetic rollover condition now that is a static rollover condition that means there's no motion in the object prior to now what makes this a dynamic rollover is going to add rolling motion to the object and now dynamic rollover is going to cover the pivot point exceeding the critical angle but now introduces a rolling motion so what does that look like let's say we have our same example of a helicopter except now engines are running we have a helicopter rotor spinning and now we're say sliding right or sliding left in the helicopter alright as we drift to say we drift to the right or center of gravity right here at our landing gear and then now we make contact with some kind of rock or something like that at this point we've introduced a pivot point we've already got some rolling motion in the odd and the object and now we exceed a critical angle which now the critical angle is going to be slightly different due to Newton's third law of motion an object in motion tends to stay in motion this is going to affect this this rolling motion and exceeding the critical angle where's in a static condition it might have only take taken say 15 degrees now we're moving along it may be 5 to 10 or 15 knots or whatever this critical angle now might have been reduced to maybe 10 five degrees or so and so we may hit a pivot point and now with just a few knots of airspeed now we have a dynamic rollover condition where the helicopter is going to make contact this center of gravity exceeds a critical angle and the helicopter continues to roll over you know in a ball of turning metal and what not destroys the helicopter so it's very important to understand this dynamic rollover because it's very very easy to get into all right well that wraps up part one of dynamic rollover recovered the what is static static rollover and dynamic rollover with a pivot point exceeding bang critical angle and rolling motion in part two I want to go over some of the causes the physical and human factors associated with it as well as how to avoid it so stay tuned with the next video or for the next video I'll put the link in the description you should see it pop open the video here thanks again for watching [Music] [Applause]