03
The Canadian HM-8 Replica
Project--Page 3
by
CONSTRUCTION DIARY
- 2003 August 9
Paul Fournier starts redrawing the plans.
The first plans he does are the drawings of the elliptic wing as shown on pages 164 and 190 of my 1931 edition. On this sketch, the ailerons stop before the elliptic tips, but Mignet indicates that it is accepted to let them go to the tip of the wing. It is the solution we choose as it is what is now done on any plane.
The ailerons controls will be copied on a modern plan and will be differential, as the solution adopted at the time by Mignet (ailerons pulled down by a cable with a piece of saw blade as spring to tighten the cable) could be dangerous.
The airfoil cannot be the original sharp nosed airfoil, as flying tests have shown that it could cause very sharp stalls. To keep faithful to Mignet's drawings, I discovered on page 63, drawing 14, the airfoil Göttingen 426 which is very similar to the Riblet airfoil. Consequently, we will use this Riblet airfoil which proved to be very efficient and reluctant to stall on several aircraft, included the German Horsa military glider and the Private Explorer of Bernard Laferrière. This kind of airfoil can be found in several places in the book, b-e page 229 fig 104.
Mignet does not recommend the plywood D-Cell for the wing leading edge, as being difficult to build. He prefers to use some kind of textile ribbon.
Because of the importance to have a consistent airfoil shape, and as this technique was commonly used for later HMs, we decided to use it on our HM-8 C ( name given by Mignet to the HM-8 with round leading edge airfoil, as shown on page 86).
- 2003 September and October
Two months of uncertainty.
I discovered by chance an unknown version of the HM-8, the HM-8 D and attempted unsuccessfully to convince Pierre Mignet that it was the last version of the HM-8 designed by his father. I contacted several collectors and builders in France who sent me unknown documentation to confirm my first discovery, I sent it to Pierre Mignet and when he was finally convinced it was too late, Paul Fournier had completed the elliptic wing drawings and did not want to start everything over again. Consequently, we will build the HM-8 C version as previously decided.
- 2003 October and November
André Létourneau starts making ribs from the templates made by Paul Fournier, but is mostly busy preparing his Osprey 2 for its first flight (after 14 years of building time)
- 2003 November 26
André Létourneau's Osprey 2 makes its maiden flight. André is very pleased and will from now on have more time for the HM-8 construction.
- 2003 December
André Létourneau completes the ribs and prepares wood for the fuselage construction.
We draw the fuselage flanks on the table and André and Paul Fournier build them.
We check every detail (tail wheel and l/G support) and make minor changes before covering them with plywood.
- 2004 January 14
Paul Fournier works with Andre Letourneau to sand and inspect the ribs. He also gives André the drawing for the wing tips bows.
- 2004 January 14
HMS sends me an email: How about we make FLOATS for HM8 also?
- 2004 January 15
Another email from HMS: "I really love the idea of floats/maybe we should show it off at Maine Seaplane event, weekend after labor day (US) in whatever year."
I give a call to Paul Fournier to make sure that he agrees to redraw the float plans and I start investigating.
On the HM-8 book, between page 106' and page 107, there is a beautiful drawing of a HM-8 on floats with a sketch and some notes about building them.
- 2004 January 16
Between two snow storms, I deliver to Beloeil the plywood I purchased in Trois-Rivières from a boat building supplier.
- 2004 January 22
Work on the fuselage flanks, see the laminated wing tip bow made by André. See the first metal parts made by Paul Fournier (Tail skid, cabane brackets, etc). Try to figure the engine stand for the Praga engine. Called Gerry, as carb and muffler are missing. Gerry says he will try and fly to Beloeil next Saturday, weather permitting. He says also that fitting the Praga on the frame may be uneasy. Ordered the streamline tubing for the cabane from Claude Guilbaut.
- 2004 January 23
HMS suggests that if the Praga does not fit easily on the HM-8 fuselage, we could install a Poinsard. However, I suggested Gerry on the phone to try and suppress the carb. heater to fix the Praga more easily.
- 2004 January 28
Gerry could not come to Beloeil last Saturday due to the cold weather (the engine of his Cessna did not start)
Work on the fuselage flanks assembly. Careful checking with the book and photographs led us to cut 1" at the bottom of the firewall and modify Paul Fournier's plans.
