FAASTeam Maintenance Safety Tip
April 2011
Hardware
Over the years, I have come into contact with many different types of aircraft hardware. Someone who is newer to the trade or a layman might think that what they are looking at is just a bolt or nut. That statement, as you know, could not be further from the truth. Because you took it off and that was the hardware that was holding it together, it must be correct. Well, that is an assumption and we all know what happens when you assume.
More than once I have been tasked with doing maintenance on this or that only to find out that the improper hardware had been used by the previous mechanic.
We as professional aircraft technicians should always look to see what the manual says the correct type of hardware really is. If the correct bolt or nut is not in stock is there another one I could use? We have to go back and dig through the manual again, don’t we. See a theme here?
The simple fact is that just because it is the same diameter and tread pitch doesn’t mean we can use it. This does not apply only to nuts and bolts. It could be something as simple as safety wire; yes, safety wire. Confused yet?
We all, from time to time, should go and reeducate ourselves on the subject of Aircraft hardware. As I learned in my early years, there is a vast difference. What is the application going to be? Is it in a hot area? Will there be torsions or will it be used in a shear application? What is the material and KSI rating* required for the application? These are just a few things that determine what will be used.
Sometimes it does one good to sit down with a good technical manual and stretch that gray matter. Someone once told me you don’t know what you don’t know! It might surprise you what you could learn.
* KSI rating = 1,000 pounds per square inch
