RV-12's Flightline Interior Arrives

Did not actually work on the RV-12 today due to other commitments, but did have some time in the morning to open the recently delivered RV-12 seating and baggage compartment carpeting kit. Before going on further, I want to say I’m very pleased with the quality of the components and stitching .... it looks great!

 I spoke to Abby at Flightline a while back and decided to upgrade the seating to leather and get a close matching vinyl for the carpet kit in the baggage area. I was thinking all leather seats were ordered but when the seats were received, they were a combination of leather and cloth. I must say it looks OK, but just not quite what I was expecting.  I would imagine the cloth inserts will be cooler to sit on during the hot and humid Midwest summer days (if we ever see any this year).  I’ll give them a try and can always go all leather if I don’t like them at a later date.

The lighting for the following photos was a mix of morning sunlight (first in a long time) and florescent lighting plus an occasional flash … so the true colors are off a bit.

Right seat and upper baggage bulkhead covering.

The carpet kit is designed to have the carpet lay on the baggage floor and then up and over the top of the fuel tank. There is a carpeted panel that will go from the fuel tank to the left skin that has a really nice storage pouch sewn onto it. The upper baggage bulkhead cover also has a nice clear pouch attached to it for displaying the aircraft registration paperwork.

Baggage compartment carpet kit components.

Both seat cushions and baggage bulkhead cover in position.

Seeing how nice and well made Flightline’s components are and especially how nice looking the storage pouch is, I’ve decided to order the pilot and co-pilot carpet kit and also get interior panels with pouches. They should just look great and be really functional.

Work Begins In Section 29

Section 29 involves construction of the forward upper fuselage. The F-1201A firewall upper is made of stainless steel and like the other two firewall components previously installed, it had edges as sharp as razor blades which needed to be deburred. The 1" Scotch-Brite wheel was used on the end of the pneumatic grinder to smooth the easy to get to edges and a small diamond hand file was used in the hard to get to places. It took a little time to remove all the sharp edges on the F-1201A, but at least the firewall upper is not lethal anymore.

Smoothing the razor sharp edges on the F-1201A firewall upper with a Scotch-Brite wheel on the pneumatic grinder.

As with other Van’s models, the RV-12 utilizes a simplistic system to attach the cowlings to the fuselage by way of hinges. The fuselage receives one half of the hinge pieces and the cowlings receive the other half …. removing the hinge pins, easily separates the cowlings from the fuselage.

The upper firewall assembly supports four hinges which need to be cut from hinge material.  The F-12116-L&R mid cowl hinges are created from two 4 1/4" hinge pieces. The F-1201J and F-1201K upper cowl hinges are made from 25 1/2" and 12 1/2" pieces of hinge material respectfully. The hinge pieces that were too long to fit the throat of the band saw were first rough cut with a hacksaw to a slightly larger than required size, then final cut using the band saw and deburred on the Scotch-Brite wheel.

Finished upper and mid cowl hinges for mounting the engine cowling onto the upper fuselage assembly.

About the time all the hinges were cut and deburred, the heater in the shop ran out of propane which abruptly terminated the “region of bearability” both burners on the heater were barely creating. The temperatures today were plummeting, so it was off to the propane supplier to refill all the tanks … which will certainly be gone by the end of the weekend if I work in the shop during this latest Artic blast.

Rudder & Brake Pedal Assembly Completed & Modification Of Master Cylinders

Work on the rudder pedals and brake assembly was completed today along with a modification to the master cylinders (more on that later).  After deburring the WD-1209 brake pedals and WD-1211 torque tubes the torque tubes were lubricated with Lubriplate Aero white lithium grease, inserted into the rudder pedals and the brake pedals were bolted in place along with the F-1290 pedal blocks. One of the reasons Lubriplate was chosen is it is a light duty grease with corrosion inhibitors.

Greasing the F-1211 torque tubes with Lubriplate Aero white lithium grease prior to insertion into the WD-1206 rudder pedal assembly.

Assembling the WD-1209 brake pedal and F-1290 pedal block onto the F-1211 torque tube.

After tightening the pedal blocks most of the pedals had tight spots caused by a slight interference of the F-1290 pedal blocks with the weldments and dragging on the rudder pedal assembly. The inner edges touching the weldments were relieved with a box cutter. The dragging was solved by using a piece of Emory cloth laid over the tubing and rotating the F-1290 pedal block back and forth over the Emory cloth thus sanding off a small portion (mostly on the outer edges) of the pedal blocks.

Emory cloth in place over the rudder tube to sand down the inner edge of the F-1290 pedal block.

After tweaking the F-1290 pedal blocks all the brake pedals moved freely which paved the way for installing the master cylinders.

All the brake pedals and torque tubes installed and ready for instillation of the four master cylinders.

Modifying the master cylinders …. The master cylinders used on the RV-12 are the same type used on other RV models. There have been a few reports of dragging brakes on RV’s (not on the RV-12 as far as I know of) which utilize a hinge assembly on the pedals as opposed to the tubes used on the RV-12. The most common solution was to use a long bolt so the two pivot points on the pedals would rotate on one single shaft. This worked well, but a few had the drag return after much use and discovered the master cylinders were not returning all the way. The solution was to install compression springs on the shafts of the master cylinders to insure a positive return. Although the RV-12 uses tubes as pivot points, suppose the possibility exists for the master cylinders to not return fully after age as some experienced with other RV models.

Decided to make a preemptive strike so the DOG Aviation procurement department rounded up the necessary hardware locally to modify the master cylinders to insure a positive return. The parts consist of a compression spring and two nylon flanged bushings for each master cylinder. Actually all that is needed is the spring but the flanged bushings are insurance that the springs won’t scratch the shafts of the master cylinders.

The upper master cylinder modified with compression spring and two flanged bushings. The individual parts are shown on the bottom.

Installing one of the modified master cylinders onto the torque tube’s mounting eyelet.

Completed rudder and brake pedal assembly with modified brake master cylinders.

The springs used for the modification are 3 1/16" long and 11/16" wide, the flanged bushings (available from Hillman) are 1" diameter with a 3/8" hole and the center “ledge” the spring slides over is 9/16" wide. The springs are probably a little stronger than necessary … but they do make for a positive return. May search around a little and see if a spring with less tension of the same dimensions can be procured.

At this point the building instructions would have the builder install the assembly into the fuselage and fabricate the brake lines … but other builders say when installing portions of the finishing kit, the pedal assembly needed to be removed. So will move on and install this later along with the brake lines … which may be custom Teflon lines with a stainless wire outer covering.

Drilling WD-1211 Torque Tubes Completed

Although a short work session in the shop today, was able to get the WD-1209 brake pedal and WD-1211 torque tubes drilled out to 1/4" … but not without a little grief. Yesterday the first two torque tubes were match drilled to #30, so the first task of the day was to install the remaining two brake pedals and torque tubes so they too could be match drilled to #30.

Second set of brake pedals and torque tubes being match drilled to #30 while the WD-1206 rudder pedal tubes are locked in the neutral position. On the right one can see how a torque tube is used to lock the two rudder pedal tubes in the neutral position while the brake pedals on the opposite side are match drilled.

The plans instruct the builder to step the holes up to #12 then final drill to 1/4" so I first went to #19, then #12 and final drilled to 1/4". This is where I had a small issue … the 1/4" drill bit began chattering and bouncing a bit when first starting into the hole … guessing  it is because the tube is round and the drill bit was bouncing on the curved edge. I proceeded and got the first hole drilled, but I did not like the chattering one bit so decided to use the drill press … so everything needed to be labeled and disassembled. Sure this may have taken a little longer, but ultimately it was a good call. To hold the alignment of the two parts I used a #30 drill bit placed into the bottom hole to lock the parts in position.

Using the drill press to drill the WD-1209 brake pedal and WD-1211 torque tube assembly to #19. The #30 drill bit in my fingers was previously inserted from below to hold the position of the parts until the #19 drill bit made its way inside the tubes.

As the holes were enlarged, that drill bit was used to hold the position of the parts from the bottom while the next larger drill bit was used in the drill press to enlarge the hole to the next size. This process was repeated until the final drill size of 1/4" was reached. All turned out well with no chattering and good hole alignment.

Here a #12 drill bit held the parts in position while the front hole was enlarged to 1/4".

All four brake pedal and torque tube assemblies final drilled to 1/4" and ready for deburring and cleanup of excess Boelube.

Work On Rudder & Brake Pedals Begins

Skipping section 25 (which involves attachment of the tail cone) decided to move onto the section 26 and complete the seats as much as possible. Even though the hinges will not be riveted in place until the pieces are painted, forward progress was made on both seats. The F-1237C seat back angles were Clecoed onto the F-1237A seat backs so the bottom hole in each seat angle and underlying components could be drilled out to #12.

Drilling out the bottom rivet hole in the F-1237C seat back angle to #12 for AN3 bolts.

After the bottom hole in each seat back angle was drilled out to #12, the parts were disassembled for deburring and reassembled for riveting. The F-1237B upper seat back angle and F-1237C seat back angles were riveted onto the F-1237A seat back. Of course, as previously mentioned, the hinges were not riveted at this time.

Riveting the F-1237B upper seat back angle onto the F-1237A seat back.

Using the pneumatic rivet puller to rivet the F-1237C seat back angle onto the F-1237A seat back.

Completed seat backs ready for the hinges when they are finally painted.

Having done as much as possible with the RV-12’s seats, for the time being, moved on to section 27 which consists of assembly of the rudder pedals and brake system.

Section 27 cover page.

Work on the rudder and brake pedals begins by cutting three nylon pedal blocks in half. Each pair of blocks becomes a bearing of sorts for the two rudder tubes that make up the heart of the rudder pedal assembly. Prior to cutting, each block was marked so both halves can be reassembled keeping the same orientation as they were cut. The band saw made quick work of cutting the nylon blocks.

Using the band saw to cut the nylon blocks in half.

All three nylon pedal blocks marked, cut and ready for assembly.

Prior to assembling any of the components, a #12 drill bit was used by hand to remove the powder coating from inside all the holes the bolts and pins will go through.

Assembling the two WS-1206 rudder pedal tubes in the nylon pedal blocks.

After the two rudder pedal tubes are supported in the nylon blocks, the components for the brake pedals are assembled. One side of the pedal assembly is locked in a neutral position and on the opposite side, the master cylinders are temporarily mounted and a pair of brake pedals are clamped vertically and match drilled into the WD-1211 torque tubes.

Sliding a WD-1209 brake pedal onto a WD-1211 torque tube for match drilling. Note how the master cylinders set the position of the WD-1211 torque tubes.

With the assembly locked in the neutral position and the master cylinders in place to set the position of the torque tube, the brake pedals are clamped in position (vertical to the work bench) and drilled into the torque tube.

Match drilling #30 the vertically clamped WS-1209 brake pedal into the WD-1211 torque tube.

Today only got as far as match drilling #30 the first pair of brake pedals. Those holes still need to be enlarged to 1/4" but I ran out of time. This was a good place to stop for the evening so will continue the drilling tomorrow.

Section 24 Completed

The finishing touches were put on Section 24 of the plans by way of riveting in place the F-1207K brace angle onto the back of the F-1207C-R baggage bulkhead and then riveting the F-1207J attach angle in place.

Prior to riveting the F-1207J attach angle onto the right baggage bulkhead (which becomes the rear mounting point for the fuel tank), the plans instruct the builder to install a nutplate onto the angle prior to instillation onto the bulkhead. Which I did per the plans only to discover with the nutplate in place, riveting the top rivet is very difficult. I would strongly suggest to fellow builders … consider riveting the nutplate ATER the attach angle is riveted onto the bulkhead.

Gaining access to the top rivet was difficult with the nutplate riveted in place… needed to use the offset tool and the close quarter rivet puller. As it was, there was just barely enough room to get onto the rivet.

Riveting the F-1207J attach angle onto the F-1207C-R baggage bulkhead.

AN OOPS MOMENT. Recently, Van’s made a modification to the RV-12’s fuel system and has changed over from using a vented fuel cap to venting the fuel tank by way of a vent line. This change was made after my fuselage kit was purchased … so my drawings make no reference to two rivets that need to be left open for instillation of a support bracket onto the backside of the baggage bulkhead for the vent line. In the back of my mind I thought there was an issue here and prior to riveting the F-1207J attach angle I rechecked the drawings and subsequently riveted all the rivets. Feeling there was still an issue here, did more in depth research and indeed discovered two rivets holes need to be left open. So the two rivets were carefully drilled out without creating any issues.

The two rivets that needed removed from the F-1207J bracket … the rivet holes here need to be left open for later instillation of the new fuel vent line support bracket.

With the exception of the F-1254 support frames, work in section 24 is completed. The support frames can be added at any time and if left off for the time being, will be one less thing to get clothing snagged on while leaning into the fuselage running wires, controls, ect.

Section 25 has the builder mate the tail cone with the fuselage which I can not do in the shop … so will skip that part of the assembly for the time being. Reading the forums, it appears many RV-12 builders suggest holding off attaching the tail cone until the very end of the build, so I feel comfortable moving onto section 26.

Working again in section 26 of the assembly plans, continued making progress on the RV-12’s seats and match drilled the remaining pair of hinges (cut during a previous work session) which attach onto the back of the seats.

Match drilling the remaining hinge to the seat back.

 

Won’t be able to assemble much of the seats because I want to prime and paint the hinges. But will try to get all the drilling out of the way now and then move onto section 27 assembling the rudder and brake system. Won’t be needing seats for quite some time.

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Baggage Bulkhead & Roll Bar Brace Completed

A short session in the shop today produced two finished components. First, the baggage bulkhead assembly was riveted onto the F-1207B bulkhead and the aft flanges of the F-1224-L&R baggage floors.

Riveting the baggage bulkhead onto the aft flange of the F-1224-L baggage floor.

Secondly, the F-1232B-L&R roll bar brackets were riveted onto the F-1232A roll bar brace and then the roll bar brace assembly was riveted into position between the roll bar and the baggage bulkhead assembly.

Using the pneumatic rivet puller to rivet the F-1232B-R roll bar brackets onto the F-1232A roll bar brace.

Riveting the roll bar brace assembly onto the roll bar assembly.

Riveting the aft end of the roll bar brace onto the baggage bulkhead.

Completed roll bar brace … yep, it’s sturdy.

Baggage Bulkhead Set In Place

Taking advantage of the one day heat wave on Thursday, the F-1207C left and right baggage bulkheads were taken out to the shed and mated with the RV-12’s tail cone so the tail cone’s shear clips could be matched drilled to the F-1207C baggage bulkheads.

The plans have a small error in that they would have the builder attach the bulkhead  then they say to draw the centerline on the face of the shear clips. I would submit draw the lines first, then place the baggage bulkheads over the shear clips and commence match drilling.

The shear clips need to have a center line drawn onto the front of the flange so when the F-1207C baggage bulkheads are set in place the holes can be drilled on the centerline.

Match drilling the F-1207C-L baggage bulkhead into the shear clips on the tail cone.

Completed match drilled holes into the tail cone’s sear clips.

Builders using Van's LP4-3 rivets  can ignore this paragraph. Builders dimpling their RV-12 take note ... I noticed a small anomaly after placing Clecos in the flanges of the F-1207C baggage bulkheads. The bulkhead's flanges were not sitting perfectly flat on the tail cone’s skin. Upon close inspection, I noticed there were rivet holes in the gaps between the flanges. These in-between holes can be seen if zooming in on the above photo with the baggage bulkhead in position. Because the rivet holes in the tail cone’s skin were dimpled, the edges of the flanges on the F-1207C bulkheads were ridding up a little on the in-between dimples. To resolve the issue, used the dimple dies with the holes in them for a nail and used the hand rivet puller to re-dimple the dimples with the bulkhead in place ... this reshaped the edges of the flanges on the F-1207C baggage bulkheads to conform to the dimples on the tail cone skin. Problem solved. will not have any issues here.

The plans instruct the builder to rivet nutplates onto the F-1207A&C baggage bulkheads along with the F-1207D baggage bulkhead channels. After placing the nutplates in position with Clecos, decided it would be easier to suspend the assembly for riveting which ultimately worked out great.

Using Clecos to secure the nutplates and baggage bulkhead parts together.

Using the pneumatic rivet squeezer to rivet the nutplates and baggage bulkhead channels onto the F-1207C-L baggage bulkhead.

Riveting nutplates onto the F-1207A baggage bulkhead with the pneumatic rivet squeezer.

After the baggage bulkhead components and nutplates were successfully riveted together, the baggage bulkhead assembly was attached to the fuselage assembly with for riveting during the next work session.

Securing the baggage bulkhead assembly onto the fuselage with Clecos.

A Short Detour To Section 26

At this point in section 24 of the RV-12’s assembly instructions, the baggage bulkhead components are prepared for assembled. Unfortunately, one of the first tasks requires match drilling the tail cone’s shear clip to the F-1207C the left and right baggage bulkhead frames before they are riveted onto the fuselage assembly. Both bulkheads are to be temporarily Clecoed in place onto the tail cone so two holes in each of the baggage bulkheads can be match drilled into the tail cone’s shear clips.

Not happening today … the tail cone is in the shed which will require snow shoveling just to get the door open and it is cold. Tomorrow we are slated to have a one day heat wave … all the way up to 36 degrees. So plan on taking advantage of that and will get to the tail cone for the match drilling tomorrow. Meanwhile, in an effort to continue chipping away at unfinished tasks, decided to skip to section 26 and begin working on the RV-12’s seats.

Section 26 begins by instructing the builder to cut and prepare six hinge pieces which will be installed onto the seat backs. These will allow the pilot to make adjustments to the seating prior to flight and to flip the seats forward to access the pins that hold the wing spars secure. Of the six hinge pieces cut to size, the two F-1237H hinges require having one of the eyelets removed … in the photo below, the red eyelet needs to be cut away as pointed to on the lowest hinge in the photo.

Cut hinge pieces for both of the RV-12’s seats. The red eyelet needs to be removed as done on the bottom hinge in the photo.

After the hinge pieces are cut to the proper length, a locating hole is drilled into each hinge. This hole will allow each hinge to be Clecoed onto the seat back parts so the remainder of the hinge can be match drilled. The hole location was center punched and then drilled using a small drill bit to create a lead hole … then the hole was enlarged in steps to a final size of #30.

Drilling a lead hole into one of the hinge pieces.

The hinges were then Clecoed into position using the lead hole, clamped with a few Cleco clamps and then match drilled.

Using the lead hole to position the hinge for match drilling.

Match drilling one of the hinges to the seatback brace.

Hinges for both seats now match drilled.

Unfortunately, after all the drilling is over, I can’t bring myself to rivet the hinges onto the seat back parts because the hinges are not primed or painted. It would bother me to no end to have some hinges painted and others not. Last Fall I just simply ran out of time, so figured the seats could wait until spring to get assembled. So priming and painting of the hinges will be done then. After all, there’s really no rush … won’t be flying the airplane any time soon. But there sure would be a cool factor to be able to sit in the cockpit … oh well, will have to wait until Spring.