landing gear bushings
Posted: Wed May 09, 2012 7:26 am
'Make the brass bushings.
If you don't want to research the blue prints to get the original material and dimensions, then reverse engineer your original bushings in order to accurately duplicate them for your own airplane under the "owner manufactured parts rule". If over sized bushings are needed there are ways to accommodate them in a proper repair scheme or replace/repair the attach brackets, but use bushings. There is no service bulletin to replace the original material with a substitute or to remove them completely, just to inspect the bolts for evidence of wear and replace if found. If in the past bolts have failed while in bushings due to wear in just a hundred hours, imagine how fast the bolts will wear in a steel to steel contact scenario, and at the very least the protective coating will wear away and allow corrosion to begin which may allow to bolt to fail regardless of how much lube is used. The overall travel of the gear is very short but the frequency of movement
is very high especially on grass. If you are or know a DER, then write a 8110 authorizing a material replacement or elimination of the bushing, but personally these bolts are expensive and I would rather change bushings.
This is a certificated aircraft and it goes without saying as owners we want to maintain our aircraft to the highest standard, we cannot arbitrarily modify our aircraft because its cheaper or easier to do it.
If you want to pursue looking for the blue prints, the club disc is a good start, but the Smithsonian has most of them.
Jim Higham
24R46108
[Non-text portions of this message have been removed]'
If you don't want to research the blue prints to get the original material and dimensions, then reverse engineer your original bushings in order to accurately duplicate them for your own airplane under the "owner manufactured parts rule". If over sized bushings are needed there are ways to accommodate them in a proper repair scheme or replace/repair the attach brackets, but use bushings. There is no service bulletin to replace the original material with a substitute or to remove them completely, just to inspect the bolts for evidence of wear and replace if found. If in the past bolts have failed while in bushings due to wear in just a hundred hours, imagine how fast the bolts will wear in a steel to steel contact scenario, and at the very least the protective coating will wear away and allow corrosion to begin which may allow to bolt to fail regardless of how much lube is used. The overall travel of the gear is very short but the frequency of movement
is very high especially on grass. If you are or know a DER, then write a 8110 authorizing a material replacement or elimination of the bushing, but personally these bolts are expensive and I would rather change bushings.
This is a certificated aircraft and it goes without saying as owners we want to maintain our aircraft to the highest standard, we cannot arbitrarily modify our aircraft because its cheaper or easier to do it.
If you want to pursue looking for the blue prints, the club disc is a good start, but the Smithsonian has most of them.
Jim Higham
24R46108
[Non-text portions of this message have been removed]'