There was accident here in Oz a couple of years back due the lower cluster/tailboom support failing.. .. .We had a H300 with the same fatigue type crack appear in the lower cluster. Options as told to us were to weld in a whole new cluster, or have an "approved" weld repair carried out.. .. .Having a little knowledge about these members and how welding can effect them, we elected to forgo the cheaper weld repair and replace the whole cluster.. .. .If an "approved" repair is undertaken you can only rely on the procedures to get it past the "approval" process.. .. .Even then you as the Pilot ought to keep a damn good eye on it.. .. .A very Sad case all round.. .. .fly safe. .Hone