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Gear Doors:


  We wanted the front gear doors to close as airtight as possible to prevent cold air entering the fuselage and also to cut down on drag and noise. The other problem we observed is that the gear doors tend to relax and their curvature changes with temperature, preventing a tight fit. For these reasons we included a flange on the fuselage gear door opening, so the doors would have something to close against. See last picture) The front gear door hinge pattern provided in the factory manual results in gear doors that do not open wide enough. Use of the standard hinges inevitably results in slots having to be cut in the fuselage to allow adequate opening.



  Adding a flange would exacerbate the problem., so naturally we had to make bigger better gear door hinges. These are beefier than standard so that we can lower the gear just a little faster without the doors blowing away. The hinge mounting points are also stiffer with carbon reinforcements. The gear doors were also covered with one layer of carbon on the inside to make them stiffer and less prone to change curvature with air loads.



  The gear door opening flange and the curvature of the gear door molding were all set before the gear door hinges were attached. At this stage the door molding had not been cut down the middle. This was done after the hinges had been bonded into place. All four hinges were clamped together while being bonded to the door layup in order to maintain alignment.



  The finished doors will swing clear of the opening allowing even a slightly miss-aligned wheel to enter the gear well. Fully open they are still clear of the fuselage.



  This close up shows that there is a flange along the edge where the two doors come together. The tension on the door springs has been adjusted so that the inside door closes first every time. Note also that the actuator attach point has been reinforced with carbon. The gear door hinge bolts are turning in brass bushings, reducing friction and extending life of the bearing. This is one place where abrasion contamination will be very high.