Airworthy -- Safe

Now I have discussed the “meet the type design” requirements, let’s talk about “safe”.

What makes an aircraft safe?

If it meets the “Type Design” isn’t it “Safe”?

How is “Safe” determined?

There are several factors that can come into play to determine if the aircraft is safe.  One source is the 100 hour/annual inspection.  The foundation for the 100 hour/annual inspection can be found in 14 CFR 43, Appendix D.

As you review Appendix D will notice it talks about “inspection”, “inspect”, “condition” “operation”.

14 CFR 43 Appendix D

The primary job of the M1A1 mk1 mechanic is to INSPECT.

A mechanic will tell you every time they approach an aircraft they are inspecting it.  They are looking for oil leaks, smoke, smells and cleanliness of the aircraft.  As they get closer, the more they are looking at the aircraft.

A clean aircraft is not necessarily well maintained, but a well-maintained aircraft is always clean.

When Appendix D is read, you will find it is restating what a mechanic does with every aircraft they approach, except for removing cowling and panels.  Appendix D is guidance for a good inspection.  That is the beginning of “making a determination” if the aircraft is “safe”.  Each line item asks the question, is the item being inspected meeting the following, improper installation, poor general condition, apparent and obvious defects, and insecurity of attachment.

The Appendix D doesn’t ask about the type design.  Just like everyone in the aviation community, the expectation is all the correct parts were installed.  Just because all the correct parts are installed it doesn't mean they are in good condition.

Many items can be looked at and you can tell they have a problem.  Some are not so obvious.  An example may be on a ground run before flight.  When you’re at the end of the runway, you conduct the magneto check.  That check may be the only check to tell you the magneto is not working, or the sparkplugs are fowled.

If a bearing is worn.  The aircraft manufacturer has established the maximum play the bearing is allowed to have.  If the bearing wear is beyond those limits the aircraft may meet the type design, but it is not safe.

There is a reason for those checks.  It helps determine “Safe”.

Use the resources you have been given to determine if the aircraft is safe.  Those resources are your five senses and the documentation provided by the manufacturer.  There may be other resources available to you, use them.  It maybe they resource that saves your life or the lives of others.

Jeffery Howard

Stay Safe, Stay Strong and Stay Professional