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  1. A

    Understanding Induced Drag

    I'm trying to understand the drag and thrust curves of the plane I'm building. Profile/form drag - no problem. My sticking point right now is induced drag. All of the graphics on the topic show induced drag decreasing rapidly with increasing speed. But the equations I find on the subject, as...
  2. A

    Part 103 low speed ultralight glider design (wing)

    I need ideas of wing system for ultralight glider (such as Chanute, EasyRiser or Primary Instruction Glider) (may be biplane) low speed (25 - 40 hm/h) , weight of glider < 40 kg). My idea is next: biplane (wingspan - 6m, wing chord - 1.2m), S1210 airfoill...
  3. L

    What would be a reasonable CLmax estimate for the USA35A thick, high-lift airfoil?

    Hi, I'm trying to choose airfoils and establish wing dimensions (and high lift devices if needed) for my design. I have a low stall speed requirement (Vs0 = 42km/h [with flaps]), so I'm looking into high-lift airfoils with good stall and thick enough for a light spar. I'm trying to balance CLmax...
  4. T

    small rocket powered glider(wingspan < 3')...HELP

    hello! I am working on a small glider that will be propelled by either a B6-4 or C6-5 Estes solid rocket motor; I am writing a python script that will(hopefully) model the flight path on a 2D plane. Right now the software accounts for everything except the following aspect, and that is if we...
  5. G

    Wing In Ground Effect Craft Design

    I would like to discuss the different aerodynamic designs of wig craft. Any insight or information would be greatly appreciated. To get the conversation started I am interested in a longer range craft powered by twin engines, either Chevrolet motors or aircraft motors. A craft that is similar to...
  6. B

    Calculating or estimating forces on control surfaces

    How does one either estimate or calculate the load on control surfaces? I see examples on calculating the loads under various flight conditions like roll and pulling out of a dive, but if I wanted to calculate the load on say an aileron hinge, I'm lost.
  7. A

    MIT course: Introduction to Aerodynamics

    This course might be of interest to some on this forum: Starts August 31, 2015 Length: 16 weeks Effort: 12 hours/week About this course This aerodynamics course focuses on the study of the flow of air about a...
  8. proppastie

    Basic Aerodynamics Question Total Drag from Glide Polar

    Picking through my second reading of Hiscock and trying to sub my numbers (no surprise) I have problems. His data for the Dox is RN=10,000,000 and my calculations show my bird has RN=1,000,000. (row 7) I am trying to calculate the total drag for HP required in climb at best L/D along with...
  9. proppastie

    Abbott Aerospace Inc. Spreadsheets

    lots of interesting stuff. Hope they do not remove it. Spreadsheets | Abbott Aerospace Inc.
  10. H

    Is there a gap in ARs ?

    I could be wrong but there seems to be a gap in AR between the ultralow AR planes 1-2 ( Arup , Wingless ) and the bottem of the conventional planes 4.5 ( Cusset special ). Does the gap exist ? What "mission " could the "very low " 2.5-4 AR planes forfill ?
  11. H

    boxed in sesquiplane twin - possible improved deflection of propeller slipstream

    I have been toying with the idea of a boxed in sesquiplane twin , with junkers flaps on both wings and spoilers on main wing outer panels . I hope to gain improved low speed roll controll , lighter spar on main wing , and possibly less penelty from having the wings close togther (half cord...
  12. proppastie

    Basic Aerodynamics Question

    Looking at Gottingen 535 airfoil data: There is data point for C.P. (Center of pressure?) at 92% of chord from leading edge at -6 deg, and the C.P. curve is extended to -150% of chord from leading edge. So how is the center of pressure not on the wing, off in space so to speak, or what does...
  13. A

    Research into increasing lift without increasing wing dimensions?

    Is anyone aware of any research into increasing lift without increasing wing dimensions? I am thinking maybe along the line of micro-structures and other tricks in material types. There might not be any, but I thought I would see if anyone has come across any interesting tidbits.
  14. H

    "slowdown" or "blockage" in prop design

    I have been a heretic on this subject for quite a while. Most prop designers compensate for "slowdown" of the inbound stream resulting from the body behind the tractor prop (prop in front of cowl). I think that this is very poorly understood and that the designers are missing a lot. This post...
  15. proppastie


    While working and researching for my quest/paper airplane I found this. Lots of stuff.
  16. T

    What exactly makes a plane be STOL?

    I'm impressed. Watching YouTube videos of people in a Zenith or Highlander taking off in what looks like 45 feet. Awesome. I realize some of it is head wind. But what else has impact on fast climb rate? Reading posts like this one makes me realize how utterly uninformed I still am. Sigh...
  17. R

    Load Case Questions for LSA Electric Powered Canard

    Long time, hardcore lurker here. Finally have the confidence and time put into a design to share and try and get some feedback. This is a long one, please bear with me, want to share where this project came from and where we are attempting to go with it. Quick intro: Currently Mechanical...
  18. Head in the clouds

    Aerodynamics help please. 1 - Aspect Ratio

    Structures I can do but aerodynamics is not my strong point so I would appreciate any help HBAers can offer. The project is what is represented by my avatar - almost - there are some fundamental differences which will reveal themselves as the design process firms up. Essentially the intention...
  19. A

    Are wing piercing wings the future?

    Can anyone tell me more about this new wing piercing airplane from Warped Dynamics,LLC? They claim(Warped Dynamics, LLC - Home) it is the airfoil of the future were it pierces the air for reduce drag to increase fuel ecomony. They also claim it is efficient at low and high speed without the need...