GESchwarz
Well-Known Member
I think designing and building for reliability is a huge and important subject and it ought to get the attention it deserves. Being the safety nut that I am, I think about this all the time. I have studied and categorized the causes of several years worth of accident reports on the NTSB website. I don’t have all the time I would like to share what I’ve learned right this evening, but I would like to at least get it started, and get people contributing.
Not really thinking of where to begin I’ll start off with the thread that I just started today titled “Cable Guards”. The lowly cable guard is a simple piece of metal that performs a simple but critical function. It keeps the control cable on the pulley. Like any component on an aircraft, it has a job to do. There are several forms it can take, each of which will have its own unique strengths and weaknesses. It will be subject to many events and conditions that will tend to degrade or defeat the functionality of the part: Humidity, Corrosion, Vibration, Exposure to Heat, Ice, FOD, Operator Abuse, Maintainer Error, Inspector Oversight, Mechanical Overload, Mechanical Interference, Wear, Lack of Stiffness, and what did I miss?
Every part of the airplane must be considered from all of these angles and thus designed in such a way to be invulnerable to all of them. Failure with even one of them can cost you your life, often in unexpected and surprising ways. What often happens is that one part fails and as a result, another part of the system becomes stressed or is used in a way it was not intended in order to compensate for the first part that failed. Most parts are not designed for anything more than what is anticipated, therefore it fails, or begins to wear at an accelerated rate, unknown to the pilot or mechanic.
By studying failures of the past we can better appreciate the importance of the design of every part, the way it’s attached, the influences of its neighbors and its environment.
That’s all I got for now, as I got to get back to building my machine. I look forward to lots of input and lessons learned.
Not really thinking of where to begin I’ll start off with the thread that I just started today titled “Cable Guards”. The lowly cable guard is a simple piece of metal that performs a simple but critical function. It keeps the control cable on the pulley. Like any component on an aircraft, it has a job to do. There are several forms it can take, each of which will have its own unique strengths and weaknesses. It will be subject to many events and conditions that will tend to degrade or defeat the functionality of the part: Humidity, Corrosion, Vibration, Exposure to Heat, Ice, FOD, Operator Abuse, Maintainer Error, Inspector Oversight, Mechanical Overload, Mechanical Interference, Wear, Lack of Stiffness, and what did I miss?
Every part of the airplane must be considered from all of these angles and thus designed in such a way to be invulnerable to all of them. Failure with even one of them can cost you your life, often in unexpected and surprising ways. What often happens is that one part fails and as a result, another part of the system becomes stressed or is used in a way it was not intended in order to compensate for the first part that failed. Most parts are not designed for anything more than what is anticipated, therefore it fails, or begins to wear at an accelerated rate, unknown to the pilot or mechanic.
By studying failures of the past we can better appreciate the importance of the design of every part, the way it’s attached, the influences of its neighbors and its environment.
That’s all I got for now, as I got to get back to building my machine. I look forward to lots of input and lessons learned.
Last edited: