Decalage angle

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

poormansairforce

Well-Known Member
Joined
Mar 28, 2017
Messages
937
Location
Just an Ohioan
View attachment 88124

Have a closer look at the trailing edge just in front of the prop.

The noise reduction was remarkable.
Thank you. Looks like another attempt to organize air flow if front of propeller and as result improving efficiency. Prop extension on 912 engines limited to 120 mm. Would be nice to see the picture from the top. It is hard to make clear understanding what was really done and at what angle.
That shape came from this idea:
https://www.rcgroups.com/forums/showthread.php?1608266-Prop-Slot-Noise-Reduction-Design-and-Tests
 

Eugene

Well-Known Member
HBA Supporter
Joined
May 26, 2017
Messages
1,191
Location
Merrill, Wisconsin, USA
I was trying to find fuselage tuft testing video and found this one. I understand now that I have very long.....long....long....long....long....long way to go! ("Six Days Seven Nights" with Harrison Ford)

 

Tornado Flyer

Active Member
Joined
May 19, 2015
Messages
38
Location
Beech Bluff, TN USA
Thank you. Looks like another attempt to organize air flow if front of propeller and as result improving efficiency. Prop extension on 912 engines limited to 120 mm. Would be nice to see the picture from the top. It is hard to make clear understanding what was really done and at what angle.
No, the controls where just not inline.
Not in line? Who puts ailerons that small and that far inboard? They would be ineffective.
 

Eugene

Well-Known Member
HBA Supporter
Joined
May 26, 2017
Messages
1,191
Location
Merrill, Wisconsin, USA
This time at Oshkosh I spend some time looking at Icon A5. Because I feel so much smarter today than 2 years ago, I see the reason why this aircraft is not very fast. That big boat on the bottom creating a lot of drag. Somewhat similar to my situation. Because I don't need to land on water = there is hope for improvement.

Screen Shot 2019-08-29 at 21.40.48.png icona5_329114.jpg fullsizeoutput_17cb.jpeg fullsizeoutput_17c9.jpeg
 

Eugene

Well-Known Member
HBA Supporter
Joined
May 26, 2017
Messages
1,191
Location
Merrill, Wisconsin, USA
IMG_2997.JPG fullsizeoutput_17c1.jpeg

Found something else interesting about my airplane. I was taking some measurements for new metal structure on my afterbody project. Idea is to connect everything to the screws you can see on my pictures. I was getting different measurements from left side to right side. I tried many times and and it was starting making me crazy! And I didn't drink that day at all!!!

Turns out composite fuselage has difference in dimensions by about 22mm or almost 1 inch. Airframe is all symmetrical. Only fuselage was made that way. Not sure what to make of it. I am sure that I can make it work. But how did that happened ??? . In aircraft manufacturing 22 mm difference is normal? Below 100 MPH we don't worry about little thins like 22mm difference???

fullsizeoutput_17a1.jpeg

Sounds like they all made that way and left fender always rubbing.


IMG_1743.jpg
 
Last edited:
Top