Slip Slidin' Away

[Witch]

I did something that although my instincts told me was probably the better thing to do, my FI said it wasn't.

 

I was landing on an asphalt slope, and as the left skid made contact with the ground and I was starting to bring the right skid down, the left skid lost friction and started sliding down hill. I felt the machine sliding to the right and so I poped the collective up and centered the cyclic and got into a hover.

 

My FI told me that that's the wrong thing to do because the skid could have caught and caused a rollover. The proper thing to do is lower the collective and get the bird on the ground.

 

Delimma: If I lower it onto the ground while skidding sideways, might the right skid have a better chance to catch and cause a rollover, while getting off the ground might catch the left skid causing a rollover? I haven't seen anything addressing this scenerio in the POH or Rotorcraft handbook or on here.

 

I spoke with another, and it seems that it can go both ways;six to one, half a dozen to the other.

 

Thoughts?

 

Later

Edited November 4, 2007 by Witch

[southernweyr]

The proper technique is slow controlled collective movement so that you do not allow your self to start to slide. Once a dynamic rollover has started it is extreemly difficult to stop it.

 

Now, in that situation it seems like it would be better to come back up into a hover because if you slam the collective down while on a slope sliding sidways it would be very easy for your downhill skid to hit, create a pivot point, and with the momentum that you have from your sliding and slamming down of the collective you could very easily rollover. This is especially true if you are on a slope that you aren't sure if you would have enough cyclic to make a proper set down.

 

On level ground though your FI is correct, lowering the collective should be your instinct even though it isn't right now.

[Chi-town]

To prevent your upslope skid from sliding like it did, try giving it a bit more cyclic upslope. I think you did the right thing by picking it up as long as you angle the cyclic upslope.

 

I love teaching slopes and it usually helps the student get better at their regular landings as well. Treat every pick up and set down as a slope.

[clay]

I know we all go through the basics of slope landings in training, but i found out a few things in my check ride that i never thought of. apparently my instructor forgot to mention it, but i fly the enstrom helicopters, max slope landing is 7 degrees and i knew that, just never knew how to properly gauge that. never thought of the inclinometer/ball as a gauge for that, but my DPE made that very clear to use that. The biggest thing he told me was if you don't like it, don't do it. there are plenty of other places to land. pick the helicopter up and go somewhere else. as far as the sliding, i think i agree southernweyr though, slow collective movements.