It would seem to me that on larger helicopters, where the “tip weights” are added to establish the mass balance of the rotor blade, the engineers have taken into consideration the fact that the weights will have to be added and the manufacturing tolerances of the blades being quite close the tip weights will fall into a fixed range. Knowing this they can calculate the loads of the blade on the rotorhead and allow a sufficient safety factor. It should also be noted that the high inertia rotor systems are not made that way by the addition of tip weights but by the weight of the blades themselves. If this were the case then Frank Robinson could have calculated the amount of weight addition necessary to provide a higher moment of inertia to his blades. Another point is that in AD 95-26-04, which dictated, the addition of cautions in the R-22 and R-44 POHs also stated that it was recommended that Robinson do something to increase the moment of inertia. If he had not calculated the centrifugal loads in the initial design then it would seem that in order to do so at this time he would have to completely redesign the rotorhead and the blades to take the additional loads.
This in MHO makes his statement about the difficulty of designing a high inertia rotor system in a small helicopter a bit self serving.
[ 28 December 2001: Message edited by: Lu Zuckerman ]</p>