Why I Took the Mass Properties Certification Exam

Certified.  I am a Certified Mass Properties Engineer.  I have taken the test and I passed.

Why?  After all, I am retired, nearly a septuagenarian, unlikely to be employed again, particularly as a mass properties engineer.  Right now, you can count the number of Certified Mass Properties Engineers on the fingers of one hand.  We few are the vanguard, the first of many to come.  We set the example, and that example will bring an understanding by both those certified and those who desire informed mass properties engineers that there is a basic knowledge required to be an effective mass properties engineer.

My professional journey began in the 1970’s, a time of stagflation, disco and polyester, and general malaise.  I had a technical degree (Physics) and a desire to be in aerospace.  I interviewed at several companies in Wichita, got multiple offers, and chose a company that offered subsidized flight training, as I always wanted to fly.  I started in the Weight Control group, and began calculating weight, CG, and MOI of parts, which then got integrated into a database that modeled a new aircraft.  Mathematically, the work was interesting.  As I showed ability, I was given more complicated tasks, including running plots of CG vs fuel burn, landing gear kinematics, and control surface mass properties.  I was also taking flying lessons.

My instructor, Jim, was a big man, pushing 300 pounds.  When he sat in the plane, he took all of his seat and part of mine.  Calculations showed that with full fuel, the aircraft we flew was overweight.  Nevertheless, up we went on flight after flight.  Then came the big day, my first solo, three times around the pattern, three take-offs, three landings.  Jim got out, I taxied to the end of the runway, pushed the throttle in, and I was suddenly in control of something unfamiliar.  Acceleration was, well – not brisk, but peppier than I was used to.  Climbing out, I saw climb rates much higher than I’d seen in all the times I’d flown this plane, reaching pattern altitude before reaching downwind.  And the descent to landing was shallower, to the point that I landed much farther down the runway than I had intended.  The next two circuits were similar, except I anticipated the descent rate better.

It was a revelation – what I was doing for my job was not some mathematical exercise – there were real-world consequences tied to mass properties.  I began paying attention to physical objects, subconsciously calibrating the mass properties of my world.  Length times width times height times density equals weight.  Where’s the CG of that car, vertically and front to back?  What does it weigh?  Conversely, I started the long process of seeing how a design evolves, how the different pieces fit together and what drives design decisions.  For example, the horizontal tail of an aircraft in level flight provides a downforce sufficient to equal the moment that the CG has driving the nose down about the center of lift.  How much structure is required so that this downforce tilts the aircraft without bending it?  That, plus margins drive the weight of that structure.  Over time, that became wondering how to minimize the weight without compromising some other aspect.

I changed companies and went to work in the space world – rockets and spacecraft.  Now there was another aspect added – POI.  The three-dimensional placement of individual components became important.  I learned to visualize the consequences of component placement on axis misalignment.  My second spinning spacecraft drove me to improve on the process I’d been taught.  That process utilized a program that required multiple computer runs to adjust positions, check the resulting POI’s, calculate the misalignments which then could be compared to the requirement.  I created a spreadsheet that combined all the calculations and would instantly give me the result from any change.  This had two unexpected consequences.  One, since it was fairly early in the proposal phase, I was free to experiment with component placement.  My first run of the spreadsheet, with the parts where the designers had placed them was well outside the pointing requirement.  I visualized what I was seeing spinning about and realized that if I moved a couple of components that the majority of the misalignment would go away.  I presented this concept to the team, and the chief scientist came up to me and said this solved one of his most perplexing problems.  With this as the new baseline, then it became a matter of small adjustments of other components to meet the pointing requirement.  Then came the second surprise – when we turned the proposal in to the customer, the customer was so impressed with my automated solution they requested it be given to them.

I continued my career.  People I’d worked with on one program I ran across on other programs.  I had one program director tell me “The aerospace community is small.  You can move around and meet almost everyone, or you can stay at one company and they’ll come by and meet you.”  I stayed at one company, and quite a few of those I’d worked with became leads, managers, people in high places.  And they knew me and asked for me when there were tough mass properties problems.  And this was because I had the knowledge and experience, and the people in charge knew that I had the knowledge and experience.

Today, things are different in one key aspect – there is much more turmoil in the workplace.  Fewer and fewer mass properties engineers spend their career at one company.  Those that have done so are nearing retirement or have retired.  Today’s mass properties engineer probably don’t have the luxury of long association with people in high places that have first-hand knowledge of a mass properties engineer’s experience.  Nor do they have a way to determine if their engineers actually have the knowledge to do their job.

That is until now.  The SAWE has instituted a Certified Mass Properties Engineer program.  The first few adventurous engineers have successfully passed the certification exam.  The exam itself tests an applicant’s knowledge and understanding of mass properties.  Now we have a means to objectively show management and customers that an engineer has the required knowledge to perform in a mass properties role.  This should bring confidence to customers, employers, and employees alike, that engineers know what they are doing.

Right now there is no requirement that a mass properties engineer be certified, no requirement from a customer that a company’s engineering staff include certified engineers.  But that could and should change as more engineers get certified, and the supervisors, employers and customers gain confidence in knowing that there is a standard to which their engineers strive to meet.

Circling back to the beginning – why should anyone get certified?  Two reasons immediately spring to mind, depending on where you are in your career.  If you are new or relatively new, certification will bolster your confidence and bolster your employers’ confidence in you.  And that bodes well for you career.  If you are an experienced engineer, certification also bolsters your confidence and your employer’s confidence, but it also places you on the path to mentorship.  Mentoring others not only helps the mentee, but also boosts the mentor both mentally and within the eyes of your employer.  And for someone like me, past the employment stage, it is that certification institutionalizes the mentoring relationships that I may have.

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