Ch-13

 

Chapter 13 Nose/Nose gear
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June 14, 2015

Last week, I added a master switch for the nose lift. I have the AEX Acessory Module for the www.eznoselift.com and on page nine off the install, there is a description of the auto function. The simple version of the auto function is: if the unit has power it will keep the wheel down, when you are going less than 90 knots. On the ground, the best way to lower the nose is to use the master switch and lower with a ratchet wrench. The first page of my checklist has "Nose Gear-Master Off-raise gear by hand" and then "Nose Gear-Down & Master switch-On". The nose gear will lower when the master is flipped back on and confirm that the system is working. The manual mentions using the "defeat" switch to raise the gear, but after twenty seconds, it is going to go back down and raise the plane just as your wife is trying to enter the plane. Not a good way to start a flight. During slow flight manuevers in phase I, the landing gear will lower, but that is no problem. The idea is that you are doing pattern work at a safe altitude (for me 5500 feet), so why not have it down for that. If you don't want the system to lower the gear, you can flip the master off and just in case I ever do that, my descent checklist has "Nose Gear-Down & Master switch-On"

May-July-2008
Doubleclick pics for larger images

This chapter has some suggestions on balancing the rudder pedals. There is a hinged door for the front nose wheel and a twin "fin" bumper pad with a heated pitot tube. 
Note: Changes as of January of 2013 due to ADS-B receiver
The galleries of pics will show a hinged door an those hinges were removed to allow for a metal free surface under the nose panel. I used that surface for the ADS-B UAT antenna. That calls for 120 mm square of thin aluminum as a ground plate. This addition of ADS-B "in" to the Dynon Skyview display is a major benefit now (real time, in flight weather and traffic) and allows for compliance to this new standard.
NOSE PANEL CHANGE OF PLANS 
As a direct result of the Note above for adding ADS-B and the lack of any hinges, you could do a simplier technique for the nose. If you have already placed the hinges, just take them off and use the screws to secure the door. You could make a lip on the lower side of the panel that slides under the exterior skin and use screws on the top side only.
So, no hinges and that means a panel and not a door for the nose.

 

13-1
For each contour line, I pushed a metal ruler down to the finish depth and then started contouring. I wanted to not have a reaming out of the rudder holes in NG-30 so I added another 15 ply BID hardpoint on both NG-30's. After glassing, then I bolted the two NG-30"s together and drilled all the holes including the rudder tubing holes. Next, I trial fitted everything with temporary bolts. I verified to the plans. The tip of the nose of my plane is extended to the black line on the edge of the plans page shown. In the last picture, the NG-30 assembly is attached to F-22. I used a board down the centerline of the fuselage to line the nose up as centered. I did not keep the ballast area. I cut that area out for the nose landing light and added a heated pitot tube for IFR capability.

Pic #6 above shows the manual retract shaft at an upward angle. I had to move it down to the bottom of the IP. But I did not place it in the midline of the IP. It exits just inboard of the Dynon 1000 panel on the pilot side. The arrangement pictured will not allow for the comm radio installation and will impinge on the control tubing for the elevators.

Nose Lift Wiring
In chapter 23, I have a section on wiring the nose lift. Here are some helpful facts.
1. The molex pin connectors for the nose lift are set up to use .063 size molex pin connectors and .093 size are what is available (as for as I could find).
So, I changed to .093 size plugs.
2. The P-1 and P-2 connectors have a male and female side. The male side of P-1 is fully wired and is attached to the nose lift motor. The female side of P-1 has wires to be added from the IP panel switch and from the auto extend module (P-2's female side). The male side of P-2 is also fully wired and this is attached to the auto extension module.
So, the designation of male and female sides should be written in on the wiring schematic supplied from Jack.
3. There is very limited reference to pin numbers on the P-1 and P-2 connectors. 
4. The tags are prone to loosen and slide off, so add some masking tape below and above the tag to keep them from sliding off before the wiring is done at chapter 23.
Answers to these problems are supplied in chapter 23. Don't worry about it now.
13-2

 

Pic#1-2: The first picture is different from the plans. I glassed the bottom of the fuselage and then went to the rudder pedal install. The glassing to NG-30 makes a good base. It really helps on the quality of the rudder pedal install. The two very important things that I wanted to get right were evenness of the pressure feel of the left and right and no "play" in the movement.
The "play" in the movement comes from poor drilling technique for the bolts. The inner and outer tubes must remain locked in position as you drill through the opposite side, so all four holes line up and the bolt barely fits through.
The rudder pedal tubes do not have the same pivot point through NG-30 so you have to move the "footprint" of the brake cylinders to a staggered position by the same distance. I used some bulkhead hardpoint scrap to set the outboard rotation points. The first two pictures show the attachment. I used an alan headed bolt to more easily uninstall the rudder tubing, when and if that is needed. I placed a Tee nut on the outer side of the hard point. It would be easier to use a Tee nut with prongs. I floxed in the Tee nut ( with wax on the end to allow the bolt to tighten). Doing it this way let me check for exact alignment from one side of the rudder assembly to the other and this allowed another 1/2 inch of room between the rudder pedals (since this moves the rotation point outboard). Note: the more outboard rotation point made it necessary to make a little more of a depression in the interior of the fuselage side wall where the forward side of the "T" moves. It did not cause any problem. I made reference marks on the tubing and took them to the bench and drilled the holes. See chapter 16 some pics on drilling through two tubes at one time. You can drill a 1/8th inch hole and place a finishing nail there and then drill another hole further over for the AN-4 bolts (not the smaller AN-3). The finishing nail locks the inner tube in position for drilling. Pic#6 shows the drilled tubes. The brackets for the return springs are on NG-30.

Pic#3-5: The wheel cover should add midline stiffening between NG30 and the heat duct and so I made a stronger version. Before I installed the Featherlite stut, I made a template to verify the strut length. I keep that template and used it to set the demensions of the wheel box.


13-3

This series of pictures are all about making a smooth access door that also strengthens the nose topside. Some of what you see is good and some is not so good. In chapter 9, I made wheel pants doors (in 2010) and that method for a door stop is much better but the stop has a straight surface. This surface curves and so it's not so simple.

Pic#1: The hinges are pivoting on bolts at the highest and most aft part of NG-30. The hinges are flexible and so they will flex off of the bolts to remove the door for painting, ect. I used a 1/4th inch diameter elevator bolt, but you could use a clickbond, IF you cover and bond the head to the NG-30 with a 3 ply BID patch. The cozygirrls show that technique on their site. Right now, you can access the interior of NG-30 and so you have options. I added some hardpoint material to move the rotation point up some. I used the full scale plans to make a rough template for anticipating where the top skin was going to be.

Pic#2: I used a rectangular shape piece of foam to span the space between the hinges and give a rotation that keeps the hinges from binding. This is the same principle as the hinge board on the FHC in chapter 18. I made a mess with the 5 min epoxy. I wanted the hinges to be removable from the door in case they get bent or broken.

Pic#3-4: I braced up the "hinge board" and relieved the top foam to allow the board to fit into a recess. I drilled a hole through the top foam at the four corners for guidance in making the door outline. Looking ahead to the canard cover and FHC is important in setting the stop point for the top of this door. I added a little micro to the top of the hinge door when I placed the top foam. The depression for the access to install the elevator lift tab bolts is only started in the third picture. I majorly widened it out to have plenty of room for a socket wrench.


13-4

Pic#1:Blue foam and filling in the cracks with stiff micro do not go together, so I used the painter's masking tape to bridge the gaps. It worked very well. I have recently applied micro in chapter 25 and there were very little contour issues. In the first pic, you can see the four holes that mark the outline of the support on the inner side. For the wheel pants, LE of the strakes and the strake fairings, I shaped the foam and then painted on a light coat of raw epoxy to firm up the blue urethane foam. Then when the micro is applied, you can use more pressure to even the contour of the micro.

The heated pitot tube was added later.

Pic#3: In the third picture, the door has just been cut out. I trimmed back the blue foam on the interior and glassed from the interior glassed area of the sides of the fuselage to close to the door opening. The door lips have to be added. I took the "lid" off and glassed the interior surface.

Pic#4: This shows the interior of the door after glassing. Before I glassed the lower surface of the door, I added ficro (flox and micro) to the areas where the machine screws would transition through to the Tee nuts in the lip of the door. The edges of the door must have a glass to glass bond(exterior/interior). I had to make some curve lips for the door to match against. That was tricky. I ended up bonding some scrap glass spacers on the lip surface to have the machine screws pull down flush. See 18-14 pic section for more detail on the door and future canard cover.

13-5
Heated Pitot tube
The Dynon folks have a seperate heater controller that regulates the power and prevents dangerous temperatures, so I don't have to worry about any heated up glass work. 

In some other pics you will still see a bumper/light "thing" that has been removed. After I placed the nose light in, I installed four landing lights in the strakes and I also installed a heated pitot tube. These changes made the bumper/light idea look like a bad idea, or more like a wart on the nose of the plane.
Pic #1: The heated pitot tube is from Dynon and integrates with their avionics, but is only come is the configuration fot the LE of the wing. I could have mounted it on the side of the fuselage nose, but the air may be disturbed there and the bumper should protect this install fine. 
The fittings for the 3/16th tubing are placed before the install. I ran 3/16th inch tubings from aft of the IP to the co-pilot strake forward baggage area for the ADAHRS module (box for input of airspeed and static, ect.). That location has less interference for the module and it frees up some forward of the IP space. I know that the pitot is off center, but this allows for replacement when needed.
Pic #2: The second picture shows the 1/4 inch thick glass hardpoints that are floxed in with some cross support to the sides and bottom of the NG-30.
Pic #3: The lateral forces need to be countered with cross supports between the two hard point bumpers. I used some 1/8th inch thick scraps. I put a small square of glassed foam between the two pieces as a spacer and floxed them in. Later, I took some cutting board material  and cut it to the shape of the fin bumpers, and drilled holes through it and then flared the holes for flox to lock that piece to the hardpoint. Flox does not bond to this material. It only adapts to it. You need this sandwich combination for the abuse that this will take.
Pic #4: The front view of the finished work. The cut line for the forward end of the LG was marked on the side of the fuselage to preserve that position during the finish work (see blue color).
Pic #5:  Side view.
Pic #6:  The panel area was covered with masking tape like for the tire door with the wheel pants. I also cut a strip of plastic and taped it on the aft portion of the LG cover and draped it over the area that was outlined with masking tape and marked the outline on the plastic. I folded the plastic back and then glassed the area with 2 ply BID and then finished with micro. I used a Dremel disk to cut through the 2 ply BID, but I did not try to go deeper than the masking tape. You will need to add a stop at the forward two corners of the panel opening. The panel has one piece of 6 ply scrap floxed on the aft end that articulates under the fuselage skin and two pieces of scrap floxed on the sides of the cutout. This makes the panel articulate into place and then one 6-32 Tee nut is used to secure the panel. You may need to bond a second layer of scrap on the side lips to give the correct tension of this and the right level to the panel. If you are reading this section for the panels to cover the bolt holes on the wings, then mark your outline to not cut the reinforcement fibers but with straight lines that the dremel can cut out, and you can use the same technique there.


I noticed that there are no after pics. I will post those pics soon, but currently, I am doing chapter 25 work on the bottom of the fuselage. Wayne Hicks's site has a great video of the doors in action. They work great. Just remember to slant the doors to add wind deflection to keep them open better for the retraction mode.