Page 21 - Volume 15 Number 10

When I ran my maintenance shop and got a new company truck, I kept the old one at the airport as a crew car. After several months ofdriving the new one, I used the old one to run an errand and was shocked at the slop in the steering. I didn’t remember it being that way. Nor did I recall the road noise and interior rattles I was hearing. This old truck was my daily driver for many years but these problems developed so gradually over time that I never noticed them.
Additions and Subtractions
Propeller blades erode over time from friction with the air during flight. Just look at how much paint wears off the tips of your props between Phase inspections. Fortunately, your King Air props are inspected at every Phase. The prop system is checked operationally in ground running, and the individual blades are closely inspected. Your mechanic is looking for nicks and gouges from rock strikes, hail or other FOD. Cracks will form at a nick or gouge, if not remedied early.
Metal props are dressed (filed down) to smooth out the dents and chips, then re-painted as necessary. Metal prop blades are painted to protect against corrosion. Filing and
The wear and tear from moving parts creates excess play (or slop) over a period of time. Small vibrations develop and increase slowly. This happens with anything mechanical. Aircraft propellers can go out of balance over many of hours of operation. The changes are undetectable on a flight-by-flight basis.
When this happens, dynamic prop balancing can make a big difference. The vibrations and raggedness in flight that had been slowly creeping in intensity are suddenly gone. It often elicits rave reviews such as, “I never realized it could be this smooth!” or “Wow, it’s like night and day!” and my personal favorite, “Gee, now my feet don’t fall asleep on the rudder pedals.”
OCTOBER 2021
KING AIR MAGAZINE • 19