hubcap Posted June 21, 2022 Report Posted June 21, 2022 I am interested in the performance of the 3-blade prop in climb and cruise vs the 2-blade and is there a brand preference between Hartzell and McCauley, particularly on my M20K? I currently have a Hartzell 2-blade Q-tip propeller. Thoughts? Quote
LANCECASPER Posted June 23, 2022 Report Posted June 23, 2022 Will a 3 blade you will gain take-off performance but will lose cruise speed. When Mooney introduced the Encore they tested 2 and 3 blade props and found that the 2 blade McCauley gave the best top speeds. https://www.dropbox.com/s/upjr069ra6991rt/Flying magazine article on Mooney Encore prop.pdf?dl=0 2 Quote
Sue Bon Posted June 23, 2022 Report Posted June 23, 2022 This isn't in your question, but I rented a J 3 blade prop while my J 2 blade prop was in for repairs. The three blade is easier to land. Also climbs better as state above. 1 Quote
Hank Posted June 23, 2022 Report Posted June 23, 2022 5 hours ago, LANCECASPER said: Will a 3 blade you will gain take-off performance but will lose cruise speed. That's what everyone says, but my C with 3-blade Hartzell still runs 145-148 KTAS; the Book value is max of 165 mph = 140 knots. My only speed mods are the 201 windshield and guppy mouth closure. 1 Quote
Ragsf15e Posted June 23, 2022 Report Posted June 23, 2022 4 hours ago, Hank said: That's what everyone says, but my C with 3-blade Hartzell still runs 145-148 KTAS; the Book value is max of 165 mph = 140 knots. My only speed mods are the 201 windshield and guppy mouth closure. …And an airspeed indicator adjustment… Quote
Hank Posted June 23, 2022 Report Posted June 23, 2022 38 minutes ago, Ragsf15e said: …And an airspeed indicator adjustment… Calculated using G430W. Quote
Ragsf15e Posted June 23, 2022 Report Posted June 23, 2022 1 minute ago, Hank said: Calculated using G430W. I believe you, I was just joking. However, now that you mentioned it… did you use the TAS calc page on the gns430? Because if you do that, your answer includes installation error (ias to cas) and any errors in your 55 year old asi/pitot lines. Quote
Hank Posted June 23, 2022 Report Posted June 23, 2022 10 minutes ago, Ragsf15e said: I believe you, I was just joking. However, now that you mentioned it… did you use the TAS calc page on the gns430? Because if you do that, your answer includes installation error (ias to cas) and any errors in your 55 year old asi/pitot lines. With pitot static checks every 2 years, my 52 year old asi / pitot static lines are in good shape. Nothing in them is that age any more, except for the parts riveted in place. Quote
Ragsf15e Posted June 23, 2022 Report Posted June 23, 2022 Just now, Hank said: With pitot static checks every 2 years, my 52 year old asi / pitot static lines are in good shape. Nothing in them is that age any more, except for the parts riveted in place. I’m sure it’s good, but if you wanted to know your actual tas, do a 3 way gps run and input the groundspeeds into an online calc. Or at least do a 4 way groundspeed test and average them (which is close but slight Off depending on wind). You can use the real tas to work backwards to your ias and see what the actual error is in your asi. If you don’t care about accuracy, only about trends, the tas page on the 430 is good. 2 Quote
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