Original Posted By: "barry9315"
Mike,I should have been more precise in my language and said the weight the aircraftis operated at. As William Wynne demonstrated in his opening post to this threadthat value is used to determine the lift coefficient required at cruise. And the resulting, required lift coefficient is used to determine the correctlength of cabanes based on the coefficient of lift v. angle of attack data generatedby the airfoil simulation software and the ordinates for the airfoil.I dont know under what conditions you will operate your Piet when it is completedbut constructing the cabanes equal in length may be about right. Here in Oklahoma,in the summer when most of the flying is done, we can have very hot,humid days with air densities much less than the Standard Day density that asbeen used in the calculations to this point. Add to that the fact we are notat sea level and we can see density altitudes that would require, ideally, a higherlift coefficient at cruise and other speeds. Equal length cabanes usingthe Riblett 30-612 set the chord line at 2 degrees positive relative to the toplongeron of the airframe. In level flight that would result in a lift coefficientof .67 according to my software analysis. That value is not unrealisticat all as an appropriate cruising speed lift coefficient on a typical summerday in Oklahoma. Regardless, setting the incidence a bit too positive does havesome benefit in creating profile lift from the fuselage, reducing the deckangle when landing and so on.I say use the cabanes you have built. It will probably fly great.Doug WrightStillwater, OKRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: fill & bleeding brakes on kolb
Pietenpol-List: fill & bleeding brakes on kolb
Pietenpol-List: Re: fill & bleeding brakes on kolb
Original Posted By: "tools"
Thanks for all of the information/ suggestions. We did two more flight tonight,one with 25 lbs ballast and one with 50. Each one reduced stick pressure slightly,but it is still there.....I also double stuck taped a digital level to thetop longeron to document the angle while at cruise. It showed it to be 0.2to 0.5 down angle.....that seemed really good, I was expecting more. It seemedto fly well " seeming" a little faster indicating 75 mph. My brain is tellingme I need to shorten the " rear" cabane. Now there is a bunch of informationshowing the front cabane should be shorter..... This flight was at 1050 lbsNext I am going to block the fuse level and recheck everything rigging wise usingwater levels for the wings and double check squareness.--------NX321LRNow test flying!!Mitsubishi PoweredRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: fill & bleeding brakes on kolb
Thanks for all of the information/ suggestions. We did two more flight tonight,one with 25 lbs ballast and one with 50. Each one reduced stick pressure slightly,but it is still there.....I also double stuck taped a digital level to thetop longeron to document the angle while at cruise. It showed it to be 0.2to 0.5 down angle.....that seemed really good, I was expecting more. It seemedto fly well " seeming" a little faster indicating 75 mph. My brain is tellingme I need to shorten the " rear" cabane. Now there is a bunch of informationshowing the front cabane should be shorter..... This flight was at 1050 lbsNext I am going to block the fuse level and recheck everything rigging wise usingwater levels for the wings and double check squareness.--------NX321LRNow test flying!!Mitsubishi PoweredRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: fill & bleeding brakes on kolb