After we complete our RV’s and have the inaugural first flight we become very familiar with all the sounds our RV’s make. Even through with the wonderful technology of ANR headsets we can still hear the “personality” of our RV’s. One of the most important sounds is the engine.
One becomes accustom and intimately familiar to the variety of sounds that emanate from the beast in the front of your RV. When the beast’s personality changes you take notice real fast. Occasionally I experience a change and I hope there is someone with a similar experience and an explanation.
I have an RV-7A with an IO-360 with a Hartzell CS prop. I have 280 hours on my bird and am intimately familiar with the engine behavior and sounds. The other day I was flying along at 5.5K at approximately 125 KIAS at 2450 rpm with a 21 kt head wind. It was a site seeing flight around some local mountains. It was a little turbulent most likely do to wind shear it was too early for thermals (6:30). I started noticing a slight change in the tone of the engine. One might call it a frequency change. It grabbed my attention, I checked the engine instruments (EFIS/EMS) all good and I reduced power a bit to see if that would change the tone. It did but I still was a bit uneasy with the initial change. I continued on with my flight and changed directions and increased power. The rest of the flight was uneventful.
I am trying to figure out why the change in tone of the engine. I am wondering if the headwind could have been varying in direction and causing the tone change. Occasionally I have experienced a tone change when performing a run up with varying wind. Could this change in the tone while airborne be caused by the 21 kt headwind changing direction?
Any thoughts or experiences would be helpful.
One becomes accustom and intimately familiar to the variety of sounds that emanate from the beast in the front of your RV. When the beast’s personality changes you take notice real fast. Occasionally I experience a change and I hope there is someone with a similar experience and an explanation.
I have an RV-7A with an IO-360 with a Hartzell CS prop. I have 280 hours on my bird and am intimately familiar with the engine behavior and sounds. The other day I was flying along at 5.5K at approximately 125 KIAS at 2450 rpm with a 21 kt head wind. It was a site seeing flight around some local mountains. It was a little turbulent most likely do to wind shear it was too early for thermals (6:30). I started noticing a slight change in the tone of the engine. One might call it a frequency change. It grabbed my attention, I checked the engine instruments (EFIS/EMS) all good and I reduced power a bit to see if that would change the tone. It did but I still was a bit uneasy with the initial change. I continued on with my flight and changed directions and increased power. The rest of the flight was uneventful.
I am trying to figure out why the change in tone of the engine. I am wondering if the headwind could have been varying in direction and causing the tone change. Occasionally I have experienced a tone change when performing a run up with varying wind. Could this change in the tone while airborne be caused by the 21 kt headwind changing direction?
Any thoughts or experiences would be helpful.
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