Well, I guess that you should expect to have a LITTLE bit of repair work on your airplane at 800 hours?.
I was under the Belly of the Valkyrie a week ago, and noticed some very small cracks emanating from the belly skin under the floor (just behind the main gear mounts). This is behind the exhaust ?ramp? that people have reported as crack-prone before. Upon further examination, I found several rivets that join the span wise z-brace to the skin were beginning to pull through, and I could just barely move the skin up and down a bit. I was reminded of the fact that I had seemed to feel a bit more vibration under my feet the last few flying hours ? and this was probably the cause. A little thrumming under foot that grows very gradually can be easy to miss. I repaired the pulled-through rivets with a line of Cherry?s, and stop drilled the little cracks. A touch of red paint hid the repairs from all but me, and I?ll look at them every couple hours to make sure nothing spreads.
My exhaust system is the stock Vetterman that van?s sells, and the pipes go straight back. I have them adjusted so they are about halfway between the skin and the bottom of the cowl, and hadn?t really thought about any potential problems, despite seeing turn-down tips on many older RV?s. I gave Larry Vetterman a call, and told him what I?d found, and he said that he?d through a pair of slip-on tips to LOE for me, and we?d install them there ? he was very aware of the phenomenon, and was pretty sure the tips would be the answer.
Sure enough, I?d barely even shut the plane down at Santa Theresa when up came Larry in a golf cart, brandishing two exhaust tips and a pair of hose clamps. Two minutes later, the install was finished, and a test flight the next day was smooth and quiet. I?m pretty convinced by the noticeable change in vibration levels that the 8?s probably need these tips from the start ? I?d sure put them on if I were doing it again.
I was under the Belly of the Valkyrie a week ago, and noticed some very small cracks emanating from the belly skin under the floor (just behind the main gear mounts). This is behind the exhaust ?ramp? that people have reported as crack-prone before. Upon further examination, I found several rivets that join the span wise z-brace to the skin were beginning to pull through, and I could just barely move the skin up and down a bit. I was reminded of the fact that I had seemed to feel a bit more vibration under my feet the last few flying hours ? and this was probably the cause. A little thrumming under foot that grows very gradually can be easy to miss. I repaired the pulled-through rivets with a line of Cherry?s, and stop drilled the little cracks. A touch of red paint hid the repairs from all but me, and I?ll look at them every couple hours to make sure nothing spreads.
My exhaust system is the stock Vetterman that van?s sells, and the pipes go straight back. I have them adjusted so they are about halfway between the skin and the bottom of the cowl, and hadn?t really thought about any potential problems, despite seeing turn-down tips on many older RV?s. I gave Larry Vetterman a call, and told him what I?d found, and he said that he?d through a pair of slip-on tips to LOE for me, and we?d install them there ? he was very aware of the phenomenon, and was pretty sure the tips would be the answer.
Sure enough, I?d barely even shut the plane down at Santa Theresa when up came Larry in a golf cart, brandishing two exhaust tips and a pair of hose clamps. Two minutes later, the install was finished, and a test flight the next day was smooth and quiet. I?m pretty convinced by the noticeable change in vibration levels that the 8?s probably need these tips from the start ? I?d sure put them on if I were doing it again.
