Hello friends!
I have a question here about my PA28-235 1968 with O-540 (235hp) and constant speed prop. Yesterday, while taking off from sea level, in CAVOK and no wind conditions I found that my prop RPMs were fluctuating between 2520 - 2580 RPMs. I was climbing to 3500' and during climb time I had kind of a feeling that engine changes its sound. All temperatures and other params were in green. Fuel flow was 24 gallons which is common to my engine. I was climbing at Vy speed which is also normal and not that hard on engine. As soon as I leveled off and set my 65% flight was uneventful, everything was perfectly well.
I verified my past engine monitor logs and found that similar fluctuation, but in smaller range (2540-2580) were the case during climbs for at least previous 10 flights.
I understand that constant speed prop should adjust its RPMs during cruise as per settings however in my case I was prop full forward and engine was at max power. Is it common for RPMs to slightly change under such conditions? How does it go in your case ? What does your engine monitor says about RPMs in climb ?
I worry that it can be an evidence of some upcoming issue. It does not look to critical for me when we talk about 10-40 RPMs but what if I loose 100-200 and become underpowered, that may look dangerous.
Thank you!
I have a question here about my PA28-235 1968 with O-540 (235hp) and constant speed prop. Yesterday, while taking off from sea level, in CAVOK and no wind conditions I found that my prop RPMs were fluctuating between 2520 - 2580 RPMs. I was climbing to 3500' and during climb time I had kind of a feeling that engine changes its sound. All temperatures and other params were in green. Fuel flow was 24 gallons which is common to my engine. I was climbing at Vy speed which is also normal and not that hard on engine. As soon as I leveled off and set my 65% flight was uneventful, everything was perfectly well.
I verified my past engine monitor logs and found that similar fluctuation, but in smaller range (2540-2580) were the case during climbs for at least previous 10 flights.
I understand that constant speed prop should adjust its RPMs during cruise as per settings however in my case I was prop full forward and engine was at max power. Is it common for RPMs to slightly change under such conditions? How does it go in your case ? What does your engine monitor says about RPMs in climb ?
I worry that it can be an evidence of some upcoming issue. It does not look to critical for me when we talk about 10-40 RPMs but what if I loose 100-200 and become underpowered, that may look dangerous.
Thank you!
