Difference book >< actual modern construction


  • If you use the airfoil mentioned in the book, you MUST use the rotating rear wing too.
  • There are two airfoils which are mostly used to replace the old airfoil. NACA 23112 and HM 3.40.13 .
  • There are several ways to construct your ribs. The way mentioned in the book is OK. The ribs have to stay in the jig, so you can made two each day (one in the morning and one in the evening, rest of the time is glue drying time). But there are others that might work a bit faster.
    • Polystyrene rib: easy, less expensive, need for a hotwire (disadvantage), able to make a large number in a single day.
    • Croses rib: Easy, little bit more expensive, able to make two each time, so four each day.
    • The Open Pou system. I designed it inspired by the work of a old flying flea builder. Beware. These ribs were never tested on strength yet.
  • Bruno Corbeau gave me some other advise: d) "Use a fly-tested reflexed airfoil. With the NACA 23112 or the Mignet 34013, the main spar must be located at 21.6 - 22% of chord. Locating it at 25% would be much dangerous."


  • 100% like the book is OK. Others proved in the past that they can enter. But ... You can find plans on the internet of new sides. It will make the cockpit larger. It will make entering the cockpit a lot easier. Also you are able to place more commands like brake pedals.
  • Parts 86 in figure 133 should be glued vertical and not horizontal. Go see here.
  • Bruno Corbeau added:
    • "The plywood sides could be drawn larger. A possible design is shown here (at the bottom of the linked article) : .
      This design should be mocked up before building it. Be careful not to locate the back of the seat too aft, as the pilot could be uncomfortable with the back of his legs. [editor: you will see in the construction guide pictures of the fuselage of the HM14, that the seat is a very long one. So, the calves of your legs might touch it. And that is not very comfortable.] The back of the pilot seat and the lyre-shaped part (front point) could be enlarged as well. Keep the original angle between the two assembled sides : about 5-6°.
    • The lyre-shaped front point could be built with laminated fir lathes, instead of being cut out with a saw from a plank of hard wood. It will be much lighter and stronger.
    • The lathes # 20, 35 and 46 must be drilled before assembly.
    • The plywood parts #70 (pic. # 129-130) may be laminated on the curved sides, but do not glue them on the sides yet : protect the sides with adhesive tape to prevent the glue curing on them. After lamination, remove the two curved bows and sand their upper face properly to ease the assembly of the feet planking of the cockpit (#71).
    • A small error in numbers occured on page 247, figure 117. At the bottom of the figure you see 800+1900=2800. Everybody knows that it has to be 2700.

Landing gear

  • The one of the book is OK. A bit heavy, but still OK. It makes the CG be low at the ground. And that helps in ground maneuvers.
  • Nobody made yet a trigear. Possible reason: it would look ridiculous to mix such a retro airplane with a trigear.
  • Several made a higher landinggear. It gives the advantage that you no longer need to worry about mole-hills. But it places the CG  higher and your wingtips higher too. Will you be able to open them with a ladder? Besides ... my HM14/360 can hardly fit on a normal garage (I needed to adjust my door opening). Placing the airplane on higher legs will make it impossible.
  • Bruno Corbeau adds here:
    • "The main landing gear could be a 40 mm x 36 mm 4130 steel tube, much lighter than the doubled tubes shown in the book."


Bruno Corbeau added:

  • "The rear wing must be bolted on the fuselage : you need two fixation points for the main spar and two for the small spar. Hard wood blocks have to be added to the fuselage to reinforce the fixation points.
  • The wings spars must be built like they are on HM360 or HM293 models. They are much stronger than the 1934-36 spars.
  • Keep all the struts (front + rear) designed in the book : it is most important for the stiffness of the fuselage."


  • The book gives a very nice wingtip to look at. But ... it is a bit hard to make. And there is need for several types of ribs.
  • Squared wings are easier to make, but they decrease the lift due to the lower efficiency. You will need more runway to take off.
  • The latest plan of Pierre Mignet (Santoigne, still in development) proposed a nearly straight wing with a single rib and a rounded tip. I personally would prefer this.
  • I used myself a one rib type of wing for my Open Pou glider.