RF8001 Skis
Hi, for those of you, who do not know me, I am Thomas and I designed the RF8001 Skis.
We have been producing these skis since 1994. Never had a problem with the rodends. After hearing about the problem, we could identify, that all the rods in question were form the same batch. My guess was, maybe a soft batch, but the rod end manufacturer looked at the rodends in Question and said" everything normal ".
I then hat to analize why the rods fail or bend, when the aircraft is just pumped once or twice on the ground. With the statement of the manufacturer to have" ok Rodends", we had to look for another reason.
I successfully could damage a rodend by pulling the skis way to high when hooking up the bungees.
But some after market Brackets did not have the stop, that is needed to restrict the travel of the rodend, and these gears still had failures.
I still was sure to have a batch of soft rodends.
We had to build a test rig to test the rodend ourselves. The batch in question met the specs of the manufacturer, but other batches were 30% and more stronger that the specs called out.
To have the airplanes flying again, we shipped from the stronger batch ends out. In the meantime a solution got developed that cold be retrofit on the existing carbon yolkes.
These tests were finished on Jan 9th with the questioned batch of rodends. Even with these rodends the required forces could be now far exceeded.. Lifting of a 2700 lbs load creates no problem. On a single rodend. Beforethe mod, bending happened at around 800 lbs.
Parts for this mod will be shipped Jan 14th. Installation of the mod takes 12 minutes.
Cycling a Turbine Bird Dog ( SM1019A) fully tanked at 3700 lbs for 100 cycles showed no bends at all.
We will supply all our customers with a free set of parts , regardless how old the skis are.
I am sure that this problem is solved now and for the future.
TomD