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  1. Jean Claude

    Propellers in yaw

    Title: Propellers in yaw Author: Herbert S. Ribner NACA report n° 820 http://naca.central.cranfield.ac.uk/reports/1945/naca-report-820.pdf Comment: A propeller does not only create the axial force that is asked of it. It also creates a radial thrust as it moves in airflow with a pitch angle...
  2. Jean Claude

    Takeoff in strong crosswind.

    Recently in France a gyrocopter Calidus lay on its side because of a divergence of the flapping of the blades. Fortunately the pilot was not injured. He said, "I sure putting the stick completely on the side where the wind was coming in. Maybe not totally backward: I do not remember." My opinion...
  3. Jean Claude

    Study of flight dynamics of a gyroplane in gliding flight

    In German Unfortunately not translated https://elib.dlr.de/88528/1/IB-Seitengleitflug.pdf Autor: Falk Sachs from DLR Comment: It will take to me some time to understand how the "yaw angle" of a rotating rotor is not simply like the angle of attack of a cylindrical profile
  4. Jean Claude

    my little wooden gyrocopter

    Many details to finish before the tests
  5. Jean Claude

    Level flight before the initial climb

    I understand that the Magni M16 flight manual recommends to wait 60Kt leveling before climbing, when there is no obstacle. However, CFIs recommend this too, even when the surroundings are crowded with trees. I simulated the speed / height gain at take-off from a Magni M16 (115 HP) to 450 kg...
  6. Jean Claude

    Short run with strong prelaunch ?

    Here are my calculated comparison of classic takeoff with very powerful launchers. No hope by this means Rotor inertia: 190 kg.m2 Static Propeller Boost: 2400 N decreasing to 2100 N at 45 mph Coefficient of rolling in the grass: 4% Area of parasitic drag: 7 sq.ft Induced drag corrected by...
  7. Jean Claude

    Connection refusal problem since 12/15/2018

    Hello, When I tried to connect to our site, my computer said: Sorry, this site is not secure. To reach you, I had to ask exceptionally override. Can you fix this problem? Thank you
  8. Jean Claude

    Forum failure

    Strange functioning Messages appearing in "messages since your last visit" are invisible in the direct title search This may be the reason for the sudden drop in activity in the forum?
  9. Jean Claude

    Forum failure

    Strange functioning Messages appearing in "messages since your last visit" are invisible in the direct title search This may be the reason for the sudden drop in activity in the forum?
  10. Jean Claude

    Forum failure

    Strange functioning Messages appearing in "messages since your last visit" are invisible in the direct title search This may be the reason for the sudden drop in activity in the forum?
  11. Jean Claude

    WAM 125 Diesel engine

    https://www.youtube.com/watch?v=lSSkf7bLjC4 Too heavy, in my opinion, for a gyrocopter. But this provision could be very lightened if it were adapted to direct gasolin injection and ignition by sparks : So, as light as a conventional 3-cylinders but the same torque that a 6-cylinders, the ratio...
  12. Jean Claude

    Continue launching the rotor while the run.

    It is often believed that continuing the launch during the rolling would shorten the takeoff distance. But this is because it is assumed that the same torque continues to be applied on the shaft until takeoff rrpm. Therefore the power delivered by the launcher is increased due Power = Torque x...
  13. Jean Claude

    my cyclical plate

    Here my cyclical plate to direct command, in the course of assembly The virtuel center of the roll rotation is to level of the teeter bolt. The virtuel center of the pitch rotation is 3" below and 1" in rear for keep the feel stability. http://www.sendspace.com/file/ugu1mu
  14. Jean Claude

    Inversed Rotax 503

    The intake pipes on ROTAX's drawings are slightly sloped toward the cylinders. In the case of an inverted mounting (spark plugs below), should I reverse the pipes to keep the same slope ? Thank you for your answers.
  15. Jean Claude

    Flight performance of lightweight gyroplanes

    Tittle: FLIGHT PERFORMANCE OF LIGHTWEIGHT GYROPLANES Report: 28TH international congress of the aeronautical sciences German Aerospace Center Authors: Holger Duda, Insa Pruter http://www.icas.org/ICAS_ARCHIVE/ICAS2012/PAPERS/434.PDF Comments: In my opinion, this text contains a lot of...
  16. Jean Claude

    Effects of rotor contamination on gyroplane flight performance

    report: 41st European Rotorcraft Forum 2015 DLR (German Aerospace Center) Authors: Holger Duda, Falk Sachs, Jörg Seewald, Claas-Hinrik Rohardt http://elib.dlr.de/98019/1/ERF_2015_Duda_final.pdf Comments:This paper is very disappointing. The authors compares the engine rpm required in level...
  17. Jean Claude

    New family of blade profiles

    Tittle: THE ELABORATION OF A NEW FAMILY OF HELICOPTER BLADE PROFILES Author: J.-J. Thibert http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19810011503.pdf Comments: Airfoils ONERA OA-207, OA-209, 0A-212.
  18. Jean Claude

    Ground effect for lifting rotor in forward flight

    Title: Ground effect for lifting rotor in forward flight Authors: Harry.H. Henson Report : NASA TN D-234 http://babel.hathitrust.org/cgi/pt?id=uiug.30112106589309;view=1up Comments: Possibly usable to better predict the takeoff run of a gyroplane, taking Z/R = 0.6 and wake angle from 0...
  19. Jean Claude

    The normal component of the induced velocity in the vicinity of a lifting rotor

    Title: The normal component of the induced velocity in the vicinity of a lifting rotor and some examples of its application. Authors:Walter CASTLES, Jr and Jacob Henri DE LEEUW Report: NACA TN 2912 https://www.google.fr/?gws_rd=ssl#q=NACA+TN+2912 Comment:This works is completed by NACA TN 1319...
  20. Jean Claude

    Propeller analysis from experimental data

    Tittle: Propeller analysis from experimental data. Naca report 712 Authors: George W. Stickle and John L. Crigler Comment: A method of estimating the axial and the rotational energy in the wake as a fractional part of the propeller power is given. A knowledge of the total thrust and torque is...
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