anchor.diff:        
      CASE (22) !Module/Mesh/Field: u%InflowOnTower(:,:)   = 22;
         u%InflowOnTower(fieldIndx,node) = u%InflowOnTower(fieldIndx,node) + du * perturb_sign
  -      
  +   CASE (23) !Module/Mesh/Field: u%UserProp(:,1)   = 23; 
  +      u%UserProp(node,1) = u%UserProp(node,1) + du * perturb_sign
  +   CASE (24) !Module/Mesh/Field: u%UserProp(:,2)   = 23; 
  +      u%UserProp(node,2) = u%UserProp(node,2) + du * perturb_sign
  +   CASE (25) !Module/Mesh/Field: u%UserProp(:,3)   = 23; 
  +      u%UserProp(node,3) = u%UserProp(node,3) + du * perturb_sign
      END SELECT
         
   END SUBROUTINE Perturb_u
  
positive.code:       end do !j      
     end do !i
     
     
        !......................................
        ! default perturbations, p%du:
        !......................................
  
negative.code:       p%du(18 + k) = perturb_b(k)         ! u%InflowOnBlade(:,:,k) = 18 + k
     end do      
     p%du(22) = perturb_t                   ! u%InflowOnTower(:,:) = 22
     do k=1,p%NumBlades 
        p%du(22+k) = perturb                     ! u%UserProp(:,:) = 23,24,25
     end do      
        !.....................
        ! get names of linearized inputs
        !.....................
  