AIRCRAFT FASTENERS - WHAT IS ACCEPTABLE??
Posted: Mon Oct 05, 2020 8:24 am
Hi All,
Just replaced my propeller hub (last one got damaged somehow in the blade refurbishment process) -- I have a composite 3-blade prop -- and wanted to ask a few questions of those better qualified and experienced than I:
1. Does everyone agree that AN-type bolts and nuts should be used in this department, or not? Can a standard, non-AN, galvanised 8.8 bolt be matched with a simple (non-AN) nylock nut one can obtain from the hardware?
2. Are standard 8.8, galvanised, bolts acceptable (for fastening the hub to the gearbox output flange)?
3. Are 12.9 bolts acceptable, also galvanised, on any part of the propeller? In this case, these are the small ones holding the propeller blade root into the hub. Remember also that significant clamping force onto the blades is also provided by the M8 bolts holding the hub to the gearbox (as far as I understand).
The manufacturer informed me that the bolts supplied are perfectly acceptable, but I do receive objections from various other people in the field -- your input would be most welcome.
Thanks!
Just replaced my propeller hub (last one got damaged somehow in the blade refurbishment process) -- I have a composite 3-blade prop -- and wanted to ask a few questions of those better qualified and experienced than I:
1. Does everyone agree that AN-type bolts and nuts should be used in this department, or not? Can a standard, non-AN, galvanised 8.8 bolt be matched with a simple (non-AN) nylock nut one can obtain from the hardware?
2. Are standard 8.8, galvanised, bolts acceptable (for fastening the hub to the gearbox output flange)?
3. Are 12.9 bolts acceptable, also galvanised, on any part of the propeller? In this case, these are the small ones holding the propeller blade root into the hub. Remember also that significant clamping force onto the blades is also provided by the M8 bolts holding the hub to the gearbox (as far as I understand).
The manufacturer informed me that the bolts supplied are perfectly acceptable, but I do receive objections from various other people in the field -- your input would be most welcome.
Thanks!