Company History






The Problem

The Solution





AOPA Article

A Balancing Tour


Vibration Analysis















The idea for a specialized prop balancing business came up after a conversation between Doug Shears and a Piper Aircraft Representative in early 1990. While maintaining a fleet of aging Piper Cherokees for a flying club in Minneapolis, Doug was querying the rep about recurring spinner bulkhead cracks and was informed they were likely caused by prop unbalance. At the time Dynamic Prop Balancing was a little known technology in the Midwest and was just as new to Doug. Sensing a potential market for the service as the first advanced balancing equipment was becoming available, he became the first to purchase a digital prop balancing computer in the Midwest.

In mid 1990 Harmony Aviation began to provide the Midwest aviation community with on-site prop balancing service using the latest vibration analysis equipment. Doug realized that in order to stay busy (and remain specialized) he would have to deliver service to a large area. While he began by serving Wisconsin and Minnesota he ended up covering ten+ states in the Midwest. Currently, Doug will travel almost anywhere in the U.S. to  spin balance ("Harmonize") props for groups and/or individuals.

Initially, dynamic prop balancing was a difficult service to sell as most aircraft owners were unfamiliar with the advantages of "spin balancing" props. However, after a few years of gentle arm twisting, word got around and Harmony Aviation was off the ground. Long story short, Doug has balanced well over 6000 props since 1990. Although he humbly admits the  learning curve will never completely flatten out; still, since he started balancing so early in the game, it is not a stretch to proclaim that Doug is likely the most experienced prop balancer in the world.

In 1990 less than 2% of the entire General Aviation fleet was dynamically balanced. The percentage today (in the mid-high performance category) is fast approaching 40%. While Doug would never suggest he could take all the credit for this improvement in the numbers, still, two decades of applied pressure towards recognition of the procedure has pushed in that direction (at least in the Midwest). In any case and whatever the reason, Doug is pleased to know that so many aircraft are running much smoother and that Dynamic Prop Balancing is now recognized worldwide as a "standard best practice".

Still, with all the balancing equipment around, there are only a few truly qualified vibe control technicians with the right combination of skill, equipment and total and/or recent experience to get the job done right every time.

Doug has discovered balancing tricks that most "part timers" will never have the chance to learn. Nothing short of balancing mastery can finesse a prop/engine to run with turbine like smoothness, at all power settings. His reputation continues to reward Doug with a loyal following of return customers that would never consider anyone else for their prop balancing job; even if it means waiting a few weeks (or flying a few hundred miles) to get the job done right.