Trouble Shooting - The Question to Ask Before you Begin

Is the equipment being operated in accordance with its design limitations?  Is the equipment being operated in ignorance to, or in disregard to the manner in which the manufacturer intended? Equipment cannot be expected to operate normally when operated abnormally.

Manufacturer's establish operating limitations based on design limitations, testing, and experience. Modifications to the equipment either by physical changes or operation means that the alteration wasn't anticipated or accounted for in the original design and in the operational limitations of the equipment. Whether the equipment will operate properly or safely while still retaining an acceptable safety factor is a complex engineering question outside of the expertise of the operator and mechanic. 


The hypothesis that the modification is good can be confirmed time and time again -- but it will never be proven. You may not realize what the possible weakness in the modification is until conditions occur in which the weakness is revealed. Too often modifications are based on trying it out and seeing how it works. Whether it's a new propeller, an engine modification, or airframe modification, the criteria for sucess is often the flight experience of others. But, successful flight experience doesn't guarantee a safe or problem free design. Tacoma-Narrows-bridge, walkways of the Kansas-City-Hyatt-Regency Hotel, Mianus-River-bridge on I-95, British-Comet airplane, Japan Airlines Flight 123, China-Airlines-flight-CI-611  all provided problem-free service for decades until sudden and catastrophic failure due to serious design or maintenance flaws. 

Solutions to operation and/or design induced problems are outside of the mechanic's charter.