THE LH LANDING LIGHT

 

When I ordered the kit in 2002, there was an option for landing lights made by a company called Duckworks.  I ordered 2 landing light kits, one for each wing.  I started the installation of the LH landing light kit on September 9, 2003. A hole had to be cut in the leading edge of the wing just inboard of the wingtip.  The kit comes with a paper template to locate the hole.  The photo at left below shows the template taped to the leading edge of the left wing which has been cleco'd to the wing.  After I was sure that the template was positioned correctly, I traced a line around the hole with a fine felt tip marker (RH photo below).  There is a  mistake in the left photograph that is so blatant that it is embarrassing.  The text on the template clearly says to layout inboard side of the hole 2.5" from the first inboard rib.  I laid the hole out 2.5" from the outboard rib.  I actually did not notice this until I went to lay out the RH landing light hole.  I have even wondered if I did this on purpose since it is my opinion that the layout further outboard looks better.

 

Template on leading edge Cut lines for hole.

 

The next step was to cut the hole.  I used a Dremmel tool with a cut-off wheel for the rough cut.  I then finished edges with a large rotary file in a die-grinder.  The photo below left shows the finished hole.  After the hole was cut and finished, I trimmed and fit the Plexiglas lens.  You have to be careful.  Plexiglas is aching to crack. I left the lens about 1" larger than the hole in the wing on each edge.    I used masking tape on the leading edge to give me my basic dimension.  I then drew a line that matched the tape and trimmed to the line.  See photo below right.

 

Finished hole in leading edge Marking cut lines on lens using 1” tape

 

I did not have a special Plexiglas drill bit so I dulled the edges of a #40, #30 and a #27 drill bit.  #27 is the final size for the 6-32 screws that attach the lens.  The photo at left below shows the lens being held in place with 3/32" clecos.  What the photo doesn't show is the way I picked up the holes in the leading edge so that they would match the brackets that hold the nut-plates.  Before I put the lens in place, I placed these clips on the outside of the leading edge skin.  I transferred the screw holes to the leading edge, being careful not to drill the nutplate rivet hole to the leading edge.  I then drilled these attach holes to #40 initially.  After I placed the lens in position I transferred the #40 holes to the lens using the drill bit I described earlier.  I then upped the size to #30 – right (blurry) photo.  Ultimately these holes get dimpled for a #6 screw and the plexiglass gets a countersink at each hole.

 

#40 hole in lens Drilled up to #30

 

The photo below left shows one of the clips I mentioned earlier.  I have a nutplate cleco'd to it.  The clip is laying on the drawing that came with the landing light.  The next step is not in the plans.  Instead of countersinking the clip for the nutplate rivets, I dimpled it because the material was so thin.  This means that the nutplate has to be dimpled too.  The photo below right shows that I used the same procedure on the ribs where the landing light platform sits. 

 

Nutplate attach clip Dimpled nutplate holes on inboard rib

 

The three dimpled nutplate holes are where platform will mount to the inboard rib.  The upper two holes are not both used.  One mounts the platform with the light level with the wing.  The other mounts the platform with the light beam aimed down.  This is so you can taxi a tail dragger at night.  The photo below left shows the three nutplates mounted to the outboard leading edge rib which was already riveted to the spar (See Left Leading Edge).  Below right you can see that I painted a portion of the inside of the outboard rib flat black.  In the next set of photos below you can see that I painted the inside of the leading edge skin, the light mount platform, the nutplate clips and part of the next rib inboard flat black as well.  I just thought that the landing light cavity would look better his way.

 

Nutplates on outboard rib Outboard rib painted flat black

 

These pictures (below) were taken in the paint booth.  As I stated above, I painted everything in the landing light cavity flat black.  I did not paint the flat black until everything in the leading edge was primed.  The flat black is “rattle can.”  Rattle can paint does not stick to aluminum very well.  Besides, I had already decided to prime all of the parts on the airplane.

 

Inside leading edge flat black at light area Inboard rib, mount platform and clips

 

In the photo below left you can see the landing light mounted to its platform, peeking out of its cavity in the wing.  I think it looks good flat black but I really didn’t care for the shape of the light or the way it was mounted to the platform..  In March of 04, I was browsing the Van's Accessory catalog and I ran across the new and improved Duckworth lights that have more wattage but more importantly they are round.  I ordered a pair.  In the photo below right you can see the new landing light kit parts next to the "old" kit parts which I removed from the left wing.  Not only is this a better looking light (which is why I bought 2 more kits), but the light mount bracket is also much more professional.

 

Square light peeking out of it’s cavity “New” round landing light

 

In the photo below left it can easily be seen that the round light is sandwiched between two layers of foam to reduce vibration on its filament.  The bracket that holds the light to the mount platform is made for this installation rather than adapting some car parts to hold the light in place.  Another change in the new kit is the use of AN3 bolts instead of countersunk screws to hold the platform to the ribs.  The photo below right shows the old mount screws (RH side of photo) versus the new mount bolts (LH side of photo).  This is a much more professional installation.  At least I think so.

 

Light platform and bulb mount Hardware.  New light at left

 

In the photo below left you can see how I intended to hold the nutplate clips to the leading edge lens.  I mixed some tank sealer, put some on each clip, screwed the clips to the lens and set the lens aside for the sealer to cure.  A month later when I got back to the project, I took the screws out and found out that I had cracks in the plexiglas at all of the screw holes (photo below right).

 

Nutplate strip sealed to light lens Cracks at screw hole

 

I obviously tightened the screws too tight.  Below left is a view of one of the other screw holes.  The new landing light kit came with new lenses.  I trimmed and drilled another lens.  I mixed sealer again and attached the clips wet again.  I did not tighten the screws very tight this time.  I masked off the lens and the wing and after I installed the landing light assembly I installed the lens wet with sealer.  I smoothed the excess before I pulled the tape off.  Liquid hand soap and your finger inside a rubber glove is what is used to smooth the sealer.  The photo below right shows the light lens installed right after I smoothed the sealer.   I used lots of masking tape.  Removing masking tape is much easier than removing sealer, whether it is dry or not.

 

Another group of cracks at a screw hole Landing light lens installed (for final time?)

 

The next picture shows the completed installation with the tape removed.  The new round light is seen peeking out of its cavity.  I started the left landing light installation before the left outboard leading edge was assembled.  I completed the left landing light installation after the wing was removed from the stand and was laying on the table.  The last photo in this section was taken after I had placed the wing in the cradle I made for storing it (and the other one when I complete it).  I know that I am going to curse this installation every time I have to change a bulb.  Removing the lens will mean screwing up the paint job that will eventually be on the airplane.  But, for now, it looks good!

 

Left landing light peeking out of the wing The left wing stored in the cradle

The basic wing box is now complete as you can see in the photo above right.  The flight controls starting with the left aileron system are next.