Wing Test Fit

MVC-007S

With the right wing structure completed, it was time to fit it to the fuselage and check for spar and fuse fitting alignment and see how the bird cage of the fuse lined up with the wing root profile.  This was also the first time I could actually see how the all the plumbing terminations (fuel ports, fuel vent line, and fuel site gauge ports) fit between the bird cage structure.  With the wing in position I could also finish weld the upper pulley entry mount for the wing and evaluate where the aileron cross over balance line fairleads run through the upper head area of the cockpit. Because I was adapting a Northstar wing to a Wag Aero 2+2 Fuselage I knew there would be issues for locations of these aforementioned items but luckily I really had only one problem and that was the aileron balance line fairleads on the fuse that did not line up with the fairleads on the the Northstar wing.  I got the torch out and burned the paint off the proposed affected weld area and welded new 4130 fairlead barrels to line up with the wing. Instead of removing the old fairleads I adapted them as a crossover visor bracket.

It was also at this time I needed to make a small temporary addition on my pole barn so I could attach both wings at the same time. The photo above is when I had only enough space to attach one wing at a time. I had the wings on and off the fuselage a few different times as it was necessary to design how the flaps would function and how to trim out the wing root with the side of the fuselage.  The Northstar wing has flaps and the Wag Aero plans only used spoilers, thus I was on my own to design the pulley and cable locations between a Johnson flap bar between the seats to transit the underside of the fuselage and activate the raising and lowering of the flap system. I left the wing struts off during this process and used a temporoary brace to hold up the wings in order to expedite the design of the flap system.

 

Preparing the Wing Build

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 Unlike other Experimental Aircraft Plans I had a choice on what wings to build.  I could build the Wag Aero 2+2 Sportsman Wings per the plans or select other wing options.  The Wag Aero Wings  are wood construction with square tips and wing spoilers instead of flaps. At the time I did not have a high confidence level for fabricating wood parts and I really wanted flaps so my attention turned to a wing kit made in Canada and available for use on the Sportsman 2+2.  

The Northstar Wings are made by Custom Flight Limited of Perkinsfield Ontario. The Northstars airfoil is the same as the Proven Piper USA 35B and is totally adaptable to fitting my Wag Aero Fuse.  Morgan Williams is the owner and Chief Engineer for Custom Flight Limited and is the brightest and most knowledgable person in Aviation that I have ever met.  His company (http://www.customflightltd.com) makes the Northstar Bush Plane Kit which is a Super Cub type airframe and they sell the same wings for Sportsman builders like me.  In the next several posts I will describe a lot more about this fantastic wing kit and what a joy it was to build such an extraordinary piece of engineering.

However before proceeding I always like to point out misguided ideas I had as a novice homebuilder.  Early in the process I read somewhere the need to build an absolutely flat wing table needed to fabricate the wings.  That seemed so logical to me that I did not hesitate to build a huge 4 foot wide by 16 foot long wing table.  Later on, after purchasing the Northstar wing kit I discovered that they are assembled on a simple pair of saw horses. The Northstar instructions provide all the necessary methods for keeping things square and true.  The wing table I built would actually have been a hindrance but it was a nice work bench for other things including the installation of Micro Vortex Generators on the wings during the time of flight testing.

 

Finalizing Projects in the Vertical Stabilizer

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 Efforts were concentrated on finishing anything that would eventually get buried behind fabric. In the vertical stabilizer area I had a couple of mis-guided ideas that would later be abandoned. The first was a “Helper Spring” I found described in a Cub Club newsletter and at the time it sounded like a worthy idea.  The spring and cable were designed to attach to the top lug of the elevator bell crank and be adjusted so as to keep the elevator in a neutral position with no stick pressure.  Without the helper spring the elevator would otherwise deflect downward with the stick forward in the cockpit as with most airplanes.  The point of the helper spring was to reduce any tendency for the airplane to nose over while parked on a very windy day.  The bottom line is that I found no good way to terminate the cable to an adjustable turnbuckle in an area that would later be accessible. 

Another misguided effort was to install a VOR antenna in the upper vertical stabilizer.  At the time it seemed logical – it was how we navigated back then.  It was not a lot of work to install the antenna and associated wiring but by the time I was done with the aircraft the use of VOR navigation was quickly being replaced with GPS.  The antenna and part of the wiring remains but for all intents and purposes it is useless to me. 

The last and somewhat amusing story of the vertical stabilizer is the use a long push/pull control for adjusting the trim tab on the left elevator.  The Wag Aero plans actually called for this mechanism which is basically the same as the Vernier control as used for the throttle.  The problem is that this push/pull cable had to be nearly twenty feet long to reach the adjustment arm on the trim tab.  I called a company known to make such a cable and explained how long it needed to be and proudly announced it was for my “Homebuilt Airplane”!  The conversation suddenly shifted to, “WE CAN’T HELP YOU – Thank You Very Much!”  I called the next week and said it was for a bus and it was sent out promptly!  This was not the last time I had to be less than truthful of what I was using a part for. 

Another remaining item I needed to finish was the rudder strobe wiring that went from the power supply under the turtle deck to the bottom of the rudder and up to the strobe.

 

The Starting Point

Trip To Orillia, OntarioEvery Project has a starting point and N728DC started with a trip to  Orillia, Ontario to inspect a Sportsman 2+2 fuselage that was for sale.  In November of 1995 we packed up the family, rented a trailer and headed to Canada to inspect and possibly buy a former builders uncompleted project.  A set of color coded plans were used to inspect tube diameters and a thorough set of measurements were also taken to confirm if the fuselage fabrication was done correctly.

It turned out that everything was spot on.  The frame was square and true, the welds looked good, and there was no corrosion.  In fact it also turned out that the fuselage was actually fabricated by Wag-Aero and sold as a kit in their catalog for a much higher price.

There was still a lot of welding to complete but this fuselage would provide a huge head start to a long and complicated project.