Eli5: How is it that there are so few passenger plane crashes?

Question

They are so big and it seems like so much could go wrong yet they are statistically extremely successful.

In: Engineering

Answer 1

With regard to the Electronics and PCB Assemblies used for important equipment on aircraft these are designed and built to IPC Class 3 standard. Class 3 is defined as life/system critical equipment that must function on demand with no down time, or ” **high reliability or harsh environment electronics where acceptable downtime is zero**”

Every step of the design and manufacture has to meet Class 3 IPC standards from design, to manufacture of the bare board, assembly of the board, testing and inspection.

This is quite a high standard to achieve and comes at an increased cost.