Fuselage, MID Lower Structure (Part 31)

With the Step Attach Assemblies completed and riveted the F-01405 Bulkhead, it’s now time to install the remaining Baggage Ribs.

The first to go in are the F-01427-L & -R Baggage Ribs.  The were attached with a mixture of AN470AD4-4 and LP4-3 rivets.  The plans excerpt shows their installation location.

Next, the two F-01426-L & -R Baggage Ribs are attached to the Bulkhead with AN470AD4-4 solid rivets.

Lastly, here is the ALMSOT completed MID Lower Structure after the Baggage Ribs described above were installed.  The last step is to install the F-01430 Baggage Floor Stiffener.  In the picture below, you can see the Stiffener installed midway down the Baggage Ribs running horizontal across the baggage area.  The Baggage Floor Stiffener is attached to the F-01458-L & -R Side Frames and F-014234B-L & -R Outboard Baggage Ribs using two LP4-3 on each side.

Section Complete

Fuselage, MID Lower Structure (Part 30)

In Part 26, we almost completed construction on the Step Attach Assembly.  The last step is to install the the remaining five rivets circled below.  The top and bottom are CR3213-4-2 cherry rivets and the other three are AN470AD4-5 solid rivets.  This is the right Step Attach Assembly.....

.....and the left Step Attach Assembly.

Now, the left and right Step Attach Assemblies are riveted to the F-01405 Bulkhead as indicated in plans excerpt below.

The rivets are installed in the F-01425-L & -R Baggage Ribs flanges, through the F-01405 Bulkhead, through the F-01424-L & -R and F-01425-L & -R Baggage Ribs flanges.  Here is the left forward side showing the shop head sides of the rivets (looking aft).....

.....and the manufactured head side (looking forward).....the right side was completed the same way.

This is the F-14128-R Seat Belt Lug Bracket (riveted to the F-01424-R Baggage Rib) riveted to the Bulkhead.  The bottom rivet is a LP4-3 blind rivet due to the limited space available to shot or buck the rivet.  The left side was completed the same way.

Fuselage, MID Lower Structure (Part 29)

After clecoing the F-01404 Bulkhead to the F-01484 Center Bottom Skin, it’s now time to start riveting them together.  To start, the F-01416B Seat Rib Angles get riveted to the Seat Ribs with six LP4-3 blind rivets.  The picture below shows the location of the rivets circled in black.  This is the “outside” of the right Seat Rib.....

.....the “outside” of the left Seat Rib.....

.....the “inside” of the right Seat Rib.....

.....and the “inside” of the left Seat Rib.

Fuselage, MID Lower Structure (Part 28)

Yesterday, we completed the riveting on 4 of the 10 Ribs to the Bottom Skin.   Today, we were able to complete the remaining 6 Ribs.....132 rivets (if I counted correctly).  So, as shown below:

The F-01484 Center Bottom Skin is riveted to the Crotch Strap Assemblies, Seat Ribs, Inboard Seat Ribs, lower flange of the F-01405 Bulkhead Assembly, and the F-01448 Aft Gear Brace Assembly.

Fuselage, MID Lower Structure (Part 27)

I was able to get some help installing the F-01404 Bulkhead to the F-01484 Center Bottom Skin.  The first five rivets get installed are shown at the bottom of the plans excerpt below with the heavy black circle around them.  Then, the Center Bottom Skin gets riveted to the Crotch Strap Assemblies, Seat Ribs, Inboard Seat Ribs, lower flange of the F-01405 Bulkhead Assembly, and Aft Gear Brace Assembly.

Of the 10 total Ribs, we were able to get the four Ribs highlighted below completed.....77 rivets total.  I am working from the center of the assembly outward toward the tips.   

To accomplish the riveting, I set up my two work tables next to each other with enough room to get my creeper in between the tables.  I then set the assembly on top of the tables as shown below.  Since all the other holes have clecoes installed, it sat pretty level and stable on the table.  I used rivet tape (scotch tape) to hold the rivets in place since they being installed “upward”.  My riveting buddy used the bucking bar on the top of the assembly between the Ribs.

*****4 Ribs down, 6 Ribs to go*****

Fuselage, MID Lower Structure (Part 26)

After priming the Step Attach Weldment’s during Part 25, I was now able to start some of the assembly.  Here are the Step Attach Weldments riveted to the F-01423B-L & -R Outboard Baggage Rib.  This is the first time that cherry rivets are used in the build.  There are five rivet locations (circled below) for each Step Attach/Rib attachement  The plans have you install CR3213-4-2 in the front two holes and either CR3213-4-2 cherry’s or AN470AD4-5’s in the other three locations.  It looked a little difficult (not impossible) to install the solid rivets, so I decided to use the optional cherry rivets.  The 10 rivets circled in the picture below are the “manufactured heads” (I guess) of the rivets.....

.....and here is the “shop head” side.

The next parts to get attached were the two Step Attach Ribs using AN470AD4-4 universal rivets.  This picture shows the location of the Ribs on the assembly and the manufactured heads of the rivet locations.

Here is the shop head side of the rivets.  This area was a little tight to get your hand and bucking bar into, but not too difficult.


The F-01424-L & -R Baggage Ribs were the next parts to get riveted to the assembly.  Here is how the plans show the pieces going together.....

.....and here is where the Rib(s) and Bracket(s) were riveted to the assembly.

Here is the opposite (inside) side of the picture above showing the shop head sides of the rivets.  (The three silver shop heads are from the LP4-3 blind rivets.

This is the F-01425-L Baggage Rib clecoed into place on the Step Attach Rib (three clecos) and Step Attach Weldments (5 clecos).  These will get rivets during the next work session and the baggage area structure will continue.

Fuselage, MID Lower Structure (Part 25)

Short session tonight on the MID Lower Structure.  I started today’s session by doing a little work on the F-00016-L & -R Step Attach Weldments.  First, I countersunk the eight holes (for the nutplate rivets) for an AN426AD3 rivet as shown below in the plans excerpt.  (The F-14145-L & -R Step Attach Angles were previously prepared).  Second, I final-drilled the four holes holes shown below to 1/4”.

Since I also like to prime powder coated parts.....Lastly, I scuffed the two pieces with grey scotchbrite and primed them with Akzo.  Here’s the two Step Attach Weldments after the primer dried.

That’s it today for the MID Lower Structure.  During the next session, several pieces with begin to get riveted together.

Fuselage, MID Lower Structure (Part 24)

Yesterday, I treated several parts with Alumiprep and Alodine.....today, they get primed.  These are the F-01458A-L & -R (small ones) and F-01458B-L & -R (large ones) Side Brackets.....

.....and the F-01458-L & -R Side Frames.

The two small Side Brackets were riveted to the Side Frames using AN470AD3-3.  Here are both sides of the Frame after the Brackets were riveted into place.

The F-01430 Baggage Floor Stiffener was also primed.....

.....and received two K1000-08D nutplates with AN425AD3-3.5 rivets.

Fuselage, MID Lower Structure (Part 23)

During the last session, I treated the Step Attach Rib Doublers and Step Attach Ribs with Alumiprep and Alodine.  After allowing them to dry overnight, I sprayed them with Akzo primer this afternoon.  Here are the six pieces after letting the primer dry.

I riveted the four Doublers to the Ribs as shown below.  The four Doublers took 20 AN470AD3-3 rivets (10 on each Rib).  The manufactured heads are shown on the left and the shop heads on the right.  Each one of the Ribs also had two K1000-08D nutplates installed with two AN426AD3-3.5 rivets.

During this session, I also prepared the last few parts and pieces for this section.  These pieces came in one connected piece from Van’s known as the F-01458AB Side Brackets.  They were separated into F-01458A-L & -R (small ones) and F-01458B-L & -R (large ones).  All the edges were cleaned, holes deburred and dimpled.

These are the F-01458-L & -R Side Frames.  They have had their edges cleaned, holes deburred and dimpled.

The last piece in this section to be prepared was the F-01430 Baggage Floor Stiffener.  The edges were cleaned, holes deburred and dimpled.

The seven pieces prepared today are ready to be treated with Alumiprep, Alodine and Akzo Primer.  I will do this during the next work session.

Fuselage, MID Lower Structure (Part 22)

Now that the Ailerons are finished, I switched back to the MID Fuselage Lower Structure.  Not a very long work session, but I did prep several parts.  These four parts started their life at Van’s known as F-01495AB Step Attach Rib Doubler.  After being separated, the two bigger pieces became the F-01495A’s and the two smaller pieces became the F-01496B’s.  All four pieces had their edges cleaned and holes deburred.

Here are the F-01495-L & -R Step Attach Ribs.  These came as two pieces and didn’t have to be separated.  All the edges were cleaned and holes deburred.  Additionally, the #40 holes in the upper (nutplate locations) and lower flanges were dimpled.

After being prepared, all six pieces were treated with Alumiprep and Alodine and hung up to dry.  Tomorrow, I will Akzo prime the parts and rivet them together.

Fuselage, MID Lower Structure (Part 21)

During the last work session, I riveted the Aft Gear Brace Assembly to the Center Bottom Skin.  Today, I will rivet the F-01416B-L & -R Seat Rib Angles.  Below is the right side of the Assembly showing the manufactured heads of the single AN470AD4-7 rivet (on the top) and the two AN470AD4-8 rivets on the bottom.

Here is the aft right side showing the shop heads.....

.....left forward side manufactured heads.....

.....left aft side shop heads.

Prior to riveting the Angles to the Aft Gear Braced Assembly, the plans advised to make sure the F-01416B Seat Rib Angles and the F-01415A Seat Rib Angles are parallel with one another.  To do this, I used a ruler to verify the same measurements at the top and bottom of the Angles.  The lower measurement is 9 7/8” as shown below.....

.....and 9 7/8” at the top. Once those measurements were made, the Angles were clamped to the Assembly, one of the rivets was partially set, re-checked the measurement, and then completely set the rivet.  I completed the same process for the remaining two rivets.

After this was completed, the F-01404 Bulkhead was clecoed to the F-01484 Center Bottom Skin as shown in the plans excerpt below.

This is what it looks like.....

Fuselage, MID Lower Structure (Part 20)

Shown below is the final assembly of the Aft Gear Brace Assembly.  There are four parts that make up the Assembly:  

1.  F-01448A Gear Brace Angle

2.  F-01448B Gear Brace Bar

3.  F-01448C Gear Brace Brackets

4.  F-01415A Seat Rib Angles

The Assembly was first clecoed together to allow several holes to be #30 final-drilled, 1/8 final-drilled, dimpled #30, and countersunk. Once all that was completed, the Assembly was riveted together using a mixture of AN470AD4-7 and AN426AD4-7 rivets.  Here is the forward side of the Assembly showing the manufactured heads.....

.....and the aft side showing the shop head side of the rivets.  The rivets were very easily set using my pneumatic squeezer and produced perfect results.

The Aft Gear Brace Assembly will be attached/riveted to the Center Bottom Skin as shown in the picture below.  (The holes in the white circle will not be riveted at this time).  I’ve inserted all the AN426AD4-4 into the appropriate holes and taped them in place.  Here is a close up of what it looks like.

And here is an overview with both sides.

The Aft Gear Brace Assembly was put into place on the rivets shown above.  I backriveted the Assembly to the Skin and the rivets turned out perfect.  Here is the completed forward right side.....

.....aft right side.....

.....completed forward left side.....

.....and aft left side.