N247BR

Pre-Assembly Wing Install


I had originally hoped to perform the pre-assembly process over the Labor Day four day weekend.  It was a good plan but it proved to be only about half enough time to do all the steps involved.  As it turned out, it took four weekends before I could finish all of the pre-assembly steps.  (To be fair, we had a tropical storm that wasted one of those weekends.)  Before I explain all the reasons for the additional time, I have included my list of steps and the approximate order of their execution. 


  • Install nose gear wheel.
  • Install wing spar bolt capture nuts on both sides of main spar.
  • Clean out obstructions in wing spar cavity and sand/grid off any squeeze out
  • Check and sand spar glass buildups and ensure same angles and thickness.
  • Clean out area around fuselage to put out of garage.
  • Load front floorboard with sand bags.
  • Setup Cart to hold wings during installation.
  • Move right side wing out and position for install.  
  • Move fuselage outside and jack up to install wings.
  • Adjust fuselage to height and angle for right wing.
  • Slide wing onto main spar and bolt in place.
  • Move left wing outside and position for install.
  • Readjust fuselage to height and angle for left wing.
  • Slide left wing onto main spar and bolt in place.  (Had problems on this one.)
  • Level the fuselage for and aft, left and right.  (Check and double check.)
  • Mark equal positions on each wing for measurement of angle of incidence.
  • Setup jig with level guide for determining angle of incidence.
  • Set angle of incidence on left wing and clamp in place.
  • Set angle of incidence on right wing and clamp in place.
  • Check and recheck everything to ensure correct and equal angle of incidence.
  • Fabricate spacers for rear spar/rear wing spar gap.
  • Drill guide holes in rear spar and bolt in place with spacers.
  • Recheck all angles again.
  • Drill holes for rear spar guides and bolts.
  • Recheck all angles yet again.
  • Bond the rear spar spacers and bolt guides on left side.
  • Recheck for correct angle of incidence after first side. (Yes again.)
  • Bond the rear spar spacers and bolt guides on right side.
  • You might want to check the angles again but by now, you are committed.
  • Fabricate Nylon guide for flap arms.
  • Install left flap and actuator arm.
  • Trim Left flap guide and install spacer for fit.
  • Install left flap actuator arm and set angles.
  • Install Right flap and actuator arm.
  • Trim Right flap guide and install spacer for fit.
  • Install Right flap actuator arm and set to match left flap.
  • Check that both right and left flaps at same angle.
  • Raise flaps to full up position.
  • Trim the edges of the wing farings.
  • Use duct tape to provide small gap between farings and wing joggle.
  • Position lower flap / wing faring and tape into position.
  • Position upper wing faring and trial fit.
  • Sand and trim farings as needed to clean fit.
  • Position and install farings with machine screws to test fit for bonding.
  • Sand and trim under belly wing farings.
  • Cut under belly wing faring in half.
  • Trim and position under belly wing farings to wing and fuselage.
  • Locate all aileron pushrods and bond ends for one end.
  • Cut all aileron pushrods to approximate length.
  • Cut opening in fuselage for Aileron Pushrods.
  • Mount fuselage aileron bell cranks.
  • Sand all farings for bonding to fuselage.
  • Sand all bond areas on fuselage.
  • Bond wing farings to fuselage.
  • Remove wing gap covers and finish trim.
  • Mark for mounting screws and temp remount.
  • Mark location of lock nuts in wing.
  • Add trailing lip for connection to rear under wing farings.
  • Locate and mark for additional lock nuts and mounts.
  • Install all lock nuts for removable panel.
  • Fabricate landing gear bay panel.
  • Locate mounting points for landing gear cover and install lock nuts.
  • Use foam blocks to fabricate landing gear farings to fuselage.
  • Fill all voids and gaps between wing and farings.
  • Fill all voids and gaps around farings.
  • Install pushrod connections on Ailerons.
  • Size and fit aileron push rods. (Outer).
  • Size and fit Aileron Push rods (Wing).
  • Size and fit aileron push rods. (Inside.)
  • Adjust the aileron travel for both left and right wings.
  • Locate and install screws / connections for seat belts.
  • Remove all screws from cured wing farings and fill holes.
  • Sand and trim wing farings and fill for finish.
  • Add shims under hinges where indicated.
  • Finish counter sinking all aileron / flap screw heads.
  • Add locking nut tab to all hinges.
  • Complete bending and test all hinge pins.
  • Install aileron and flap hinges with adhesive and locking nuts.
  • Extend ground strap and connect to aileron hinges, counter weights, flaps
  • Cutout and glass wing tips to provide increased aileron travel.
  • Align wings and ailerons and set lengths of all push rods.
  • Reposition flaps in up position and make any adjustments needed to farings.
  • Set and position flaps to required settings (Up, 12,24,36 degrees)
  • Reset wing tips and double check all fittings.
  • Remove wing tips.
  • Remove Ailerons.
  • Remove Flaps.
  • Remove Garage side (left) wing.  (Must reposition everything to slide off.)
  • Remove Street side (right) wing.  (Must reposition everything again to slide off.)
  • Lower Fuselage back to ground level.
  • Move everything back into garage.
And I had wanted to do all that by myself in one four day weekend with temperatures in the mid to upper 90's.  Well, I didn't make it but it was a worthy goal.  The one thing that I found was that one person working on this list along will take much longer than the combined time of two people working on it.  The problem is one of logistics.  When two people are working together, they can be in to places at one time and do not need to waste anywhere near as much time getting up and down and going back and forth.  As an example, I spent almost one full day trying to set the length of the push rods and check for the proper movement of the ailerons.  Two people could have accomplished the same task in probably no more than an hour or two.  The same can be said for almost all of the critical adjustments needed for the pre-assembly operations.

Some of the specific problems I encountered during the pre-assembly process were:

  • The first real problem was the strip that had been bonded to provide an enlarged bonding area for the panel inside the spar opening in the wing.  This strip had been pushed up some during the closeout and was just enough to keep the main spar from moving down enough to get the spar bolts in place.  Sanding and grind this down took several hours and scratched up my arm considerably.

  • Setting the angle of incidence was not a real problem but it took a tremendous amount of time due to having to constantly move back and forth to check the angles.  It was a very time consuming process because of the logistics of working alone.

  • The flap actuator guide channel, which I had made in the extended length needed trimming.  Once fit without interfeerence, it proved to be too far from the guide and I had to remove it and add a 1/4" spacer.  This was repeated on the right wing as well but the spacer was a bit thinner.  I had some problems drilling the holes for mounting the flap guides but I think I did the right thing by not mounting them before.  By waiting, I was able to position the flaps, the guides, and then lock everything into the proper place.  It took more time but the flaps are exactly the same.

  • Fitting the fairings, expecially the under side fairings was not all that difficult but was time consuming because of trying to hold things in place while setting screws or tape.  Once again, it took a lot of time to position, adjust, reposition, trim, and finally set in place.  The results are great but it just took a huge amount of time.

  • Fitting the aileron controls were probably the most frustrating of all the operations.  I measured and cut, measured and cut and repeated the operations over and over.  The first wing pushrod I measured and cut but cut it about 1/2 inch shorter than ideal.  It works but I may make a new one simply to make myself feel better.  After that, I cut every thing long, fit, cut, fit, cut, and finally fit again.  I wanted to make sure that I didn't cut another one short.  The biggest problem was trying to get the proper elevator travel that I needed.  I adjusted and readjusted until I was sick of the whole thing but could not get the proper movements.  I had added spacers between station 30 and the bellcrank bracket.  I also added a 1/4" spacer to the bellcrank to position the control rod within the wings leading edge.  Still, I couldn't get the proper movement. What I had failed to remember was that the change from dual sticks to a center stick had changed the amount of movement in the controls.  I decided to move the mounting point for the fuselage bellcrank to a hole that I had added when I installed the spacer and see if things worked better.  Finally, the controls were giving the amount of movement needed.  The stick will be a bit more sensitive but I think I will like it much better.

  • Bonding of the fairings gave me two very different problems.  I had fit the fairings dry and with the flaps in their retracted position.  I then lowered the flaps and performed the bonding operation with flaps out of the way.  BIG MISTAKE.  Two problems surfaced during the bonding operation.  The adhesive was very thick and some of the adhesive pushed the gaps open between the original screws.  I had to add additional screws which in turned pulled the fairing down resulting in some distortion.  The fairing that fit over the flaps shifted slightly and the result was that the flaps now caused the fairing to bulge at the wing.  The cure is still in progress and has required several adjustments.

  • HEAT!  HUMIDITY!  The September heat wave has made everything more difficult and the work has moved much slower than would otherwise be the case.  I have to take frequent breaks to avoid heat exhaustion and by the end of the day, I feel beaten and discouraged by the progress.  

It is very possible for a single individual to perform all the tasks necessary to accomplish the preassembly and the ultimate final assembly.  It is a daunting task but with planning and time, it will prove doable.