ground loop

I never knew what a ground loop really was until I got the Spit Mk-9.:megalol::megalol::megalol:. Exellant work ED, the TFC and all involved. :joystick::joystick::joystick:

When a wing tip hits the ground (often) why doesn't it drag my aircraft back around the opposite way to my ground loop ? I' m not suggesting it's any more desirable, I'm just curious.

I'd be keen on the answer to this too ... I loop to the left with my right wing dragging :(

When a wing tip hits the ground (often) why doesn't it drag my aircraft back around the opposite way to my ground loop ? I' m not suggesting it's any more desirable, I'm just curious.

Hi,

Are you asking why it doesn't yaw the aircraft left if you scrape the left wing on the ground? (Or visa-versa).

Hi,

 

Are you asking why it doesn't yaw the aircraft left if you scrape the left wing on the ground? (Or visa-versa).

Yes, why doesn't the grounded wing tip pull the aircraft back around in that direction. I appreciate grounding a wing tip isn't good practice but I would have thought it would, if not neccesarily making things a whole lot better, at the very least go some way to counteracting the opposite loop, especially at slower speeds.

Ok, I see what you mean!

I guess in theory you might expect it to do so, but in order to do that, the contact between the wing tip and the ground would have to involve a lot of friction. By this I mean A LOT!

Picture this, if you start ground looping to the right, the natural tendency of the aircraft is to roll left. This is because as the aircraft starts to turn right, the main wheels will slip and skid. As a result, the centre of gravity will no longer be aligned with the longitudinal axis and direction of movement. As the mass of the aircraft acts on the C of G, this forms an effective moment arm which means the further around the C of G can get out of alignment, the more powerful its influence will be. This is why you only have a very narrow window of displacement in either direction to stop a swing before it accelerates out of control.

Effectively, more and more of the aircraft's mass is now trying to turn it right. The effect of the left wing tip on the ground will counter this motion to some extent, but it won't over come it, unless the wing tip encounters a solid immovable object, like someone's car for instance (I've seen that happen twice!). Under these circumstances, the aircraft will certainly stop yawing right momentarily, but the wing will probably be torn off long before the motion completely stops.

Many thanks CI, really appreciate getting the science behind what's happening, even if I'm still struggling to control it!

Yeah, ground loop seems to be the name of the game when landing this bird. LOL,

Thanks for the explanation of the physics involved chief, I've never stopped to think about it.