fuel system - velocity aircraft · 09 - fuel system january 2005 09-xlf ... 9.7.1 solid fuel line...

09 - Fuel System

January 2005 09-XLF Page 9-1

Fuel System

09 - Fuel System

Page 9-2 09-XLF January 2005

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09 - Fuel System


Contents9.0 - Chapter Preface ...................................................................................9-4

9.0.1 - Parts List ................................................................................................... 9-49.0.2 - Tools List ................................................................................................... 9-49.0.3 - Supplies List .............................................................................................. 9-59.0.4 - Glass List ................................................................................................... 9-59.0.5 - Process Overview ...................................................................................... 9-6

9.1 - Transfer Template ................................................................................9-79.1.1 - Transfer Template ....................................................................................... 9-7

9.2 - Lower Fuel Strake ...............................................................................9-99.2.2 - Preparation ................................................................................................ 9-99.2.3 - Lower Strake Alignment ............................................................................. 9-99.2.4 - Cut out Lower Baggage Access Openings ................................................ 9-129.2.5 - Lower Strake Half Glassing ...................................................................... 9-13

9.3 - Internal Strake Structures...................................................................9-179.3.2 - Baffles and Bulkheads .............................................................................. 9-179.3.3 - Install Strake Baffles ................................................................................. 9-209.3.4- Bulkhead Fuel Fittings ............................................................................... 9-209.3.5 - Fuel system venting .................................................................................. 9-22

9.4 - Upper Strake Half ..............................................................................9-249.4.1 - Fuel Cap Installation ................................................................................. 9-249.4.2 - Fitting the Upper Strake Half .................................................................... 9-249.4.3 - Upper Strake Half Installation ................................................................... 9-259.3.4 - Outboard End Strake Reinforcement ........................................................ 9-27

9.5 - Sump Tank and Fuel Lines ................................................................9-289.5.1 - Fuel lines .................................................................................................. 9-289.5.2 - Install the Sump Tank Cover ..................................................................... 9-299.5.3 - Install Mounting Tabs ............................................................................... 9-299.5.5 - Sump Tank Installation ............................................................................. 9-29

9.6 - Wing Strake Cutout ...........................................................................9-309.6.1 - Wing Strake Cutout .................................................................................. 9-309.6.2 - Wing Strake to Beam Support .................................................................. 9-319.6.3 - Installing Leading Edge of Strake onto Door ............................................. 9-32

9.7 - Fuel System Plumbing .......................................................................9-339.7.1 Solid fuel line Installation ............................................................................. 9-33

09 - Fuel System


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9.0 - Chapter Preface

9.0.1 - Parts ListPart Number Description Qty

Wing Incidence Jig 1Wing Bolts 6Wing Attach Washers 12Sight Gauge Elbow 43/8" Aluminum TubingFuel Cap 2Pilot Lower Strake 1Pilot Upper Strake 1Co-Pilot Lower Strake 1Co-Pilot Upper Strake 1Sump Tank 1Sump Tank Lid 1Aluminum Hardpoints, Sump Tank 34x8 Dyvinicel sheet 1AN816-6D 3AN818-6D 13AN819-6D 13AN822-6D 4AN827-6D 1AN832-6D 1AN924-6D 1CAV-110 1MS21042-3 4AN3-10A 4AN970-3 4

9.0.2 - Tools ListDescription

Jig SawKitchen StrainersFly Cutter (or hole saws)1/8" Pipe Thread Drill & Tap1/4" Pipe Thread Drill & Tap5/16" Drill & TapJacks for wingsI-BeamsCarpenters Square

09 - Fuel System


9.0.3 - Supplies ListDescription

EZ-PoxyMilled FiberMicro BalloonsCab-o-SilBondo1/2" - 20 Nuts (6)Structural AdhesiveFlox

9.0.4 - Glass ListType Size Qty

BID 9" x 55" (Strake Skin to Skin) 8BID 2-1/2" x 55" (Strake to Spar) 8BID 2-1/2" x Length of Strake 16BID 2' x 8' 2BID 3" x Attach Bulkheads & BafflesBID Cover Fuel FittingsBID Cover Foam At Naca VentBID Cover Around Fuel CapBID 4" x Length of Fuselage 8BID Bulkheads to Upper Strake 4TRIAX 4" x 24" 4TRIAX 4" x 28" 4BID Cover Sump HardpointsTRIAX 3" x 6" Sump Mounting Pads 12FINE Perimeter of Sump Tank 2FINE 4" x Forward Strake to Door 16

09 - Fuel System


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9.0.5 - Process OverviewPilot Co-PilotDate Date

Attach Lower StrakeCreate Transfer TemplateLevel FuselagePosition Lower StrakeTrim Lower StrakeBevel Lower StrakeAttach Lower StrakeGlass Strake to SparAttach Strake to WingCut Out Baggage Access Holes

Attach Bulkheads & BafflesTrim & Fit Upper StrakeCreate Baffles & BulkheadsTrim Baffles & BulkheadsMount Baffles & BulkheadsSeal fuel tankInstall Bulkhead Sight GaugesInstall Fuel LineInstall Fuel StrainerInstall Vent LineInstall Vent Manifold

Install Upper StrakeInstall Fuel CapFinal Fit Upper StrakeClean Tank ThoroughlySeal TankAttach Upper StrakeCut Wing From StrakesComplete Upper Strake InstallationInstall Remaining BulkheadsOutboard Strake Re-Inforcements

Sump TankInstall Hardpoints in Sump TankDrill & Tap HardpointsInstall Sump Mounting PadsInstall Sump Tank VentInstall Low Fuel Warning SystemClean TankSeal TankAttach Tank CoverAttach Tank to Fuselage

Construction Process

09 - Fuel System


9.1 - Transfer Template

9.1.1 - Transfer Template

Note: At this time it is advisable to build your wings and canard if you have notalready done so. You will need the wings and the canard mounted to thefuselage for proper mating of the fuel strakes.

If you have room to attach the wing then do so and skip this section of making a transfertemplate. The wing itself, rigged in its proper position, will then be the template to whichyou fit the strakes. It will also align/twist the ends of the carry through spar to minimize theshimming necessary for rigged flight.

Note: Avoid the transfer template if at all possible.

The purpose of this template is to transfer the shape of the leading edge wing root to theoutboard end of the wing strake without having to install the wing. In order to install thestrake halves to match the leading edge wing roots build a transfer template. Use 1/2”plywood for the templates.

It is essential that the factory cut edges be used for the ends of the patterns that join to eachother to achieve squareness. Accuracy here saves a lot of filling and sanding later andprovides a good finished appearance. See Figure 9-1.

"Root " pieceLevel wing wit h incidence t ool.Mark level line on "root " piece.

"At t ach" piece

Measure anddrill ½" holes

Trace root pat t ernand cut .

Assemble "root " pieceover "at t ach" piece - flush.Join fact ory cut edges

WingA

Figure 9-1. Transfer template construction - tracing wing root.

When the wing was built, you cut the leading edge root square with the front inboard sparface. Recheck and carefully sand for squareness.

The first step is to construct a pattern of the leading edge wing root.

___ Cut a root piece slightly larger than the leading edge wing root with a factory edge on oneend.

___ Cut an attach piece about 6" x 6" with one good factory edge (mark that edge for identity).

___ Join the two pieces at their factory cut edges, lapping the root piece over the attach piece,keeping the joining edges absolutely flush. Measure from the leading edge wing root to theattach bolt hole centerlines.

___ Transfer these measurements to the outside of the attach piece and drill the two 1/2” holes.

___ Install joined pieces to the wing and trace the leading edge root shape onto the root piece.

___ Level the wing using the incidence tool provided. Mark a level line on the root piece.Remove the pattern assembly and carefully transfer the level line to the opposite side.

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Drill new ½" holest hrough old holes Transfer level line ont o

opposit r side - carefully.

½" overlap - be precise

Mark posit ion relat ive t o"root " piece on new"at t ach" piece.

A

Figure 9-2. Transfer template replicate attach process.

Disassemble and cutalong marked "root " pat t ern line

Assemble "at t ach" pieceover "root " piece, edges flush

Reinforce and bondo ona small square.

Spar

A

Figure 9-3. Transfer template - final assembly.

___ Cut another attach piece as before. Align and clamp this piece so that the factory edgeextends 1/2” beyond the outside corner of the pattern assembly. Be precise and check the1/2” extension along its full length.

___ Drill holes in the new attach piece using the old holes as a guide. Carefully mark therelative position of the new attach piece to the root piece. The transferred level line is agood point of reference.

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09 - Fuel System

January 2005 09-XLF -9

9.2 - Lower Fuel Strake

9.2.2 - Preparation

___ Level your fuselage fore and aft, and install one wing at a time, both wings if you haveroom. If you do not have room, build the transfer template described in Section 9.1.1.

___ Using your wing attach bolts for fit, go to the hardware store and get some 1/2”-20 nutsand save your locknuts for final assembly.

___ Once the wing(s) is bolted to the center section spar, check the level of the wing using yourincidence block.

___ To adjust to level, support the wing outboard, and twist the spar with the wing by shim-ming the outboard support until zero incidence is achieved. Be sure that nothing movesduring the strake installation process.

The strakes take all the torsional loading back into the fuselage and they are not rigid untilthe upper halves of both the strake and the fuselage are complete.

If you are using transfer templates, twisting of the spar becomes difficult, so shim washersmust be used if any variations occur. (Keep track of how many washers are used and theirpositions).

Note: The next paragraph is of critical importance!

9.2.3 - Lower Strake Alignment

The elevation of the leading edge of the strake at the fuselage side (Point A) with respectto the elevation of the bottom of the lower spar cap (Point B) is of great importance. Thestrake leading edge must be 2-7/8" +- 1/8" higher than the lower spar cap at theside of the fuselage.

Leading edge strake (point A)

Bottom of spar cap(Point B)

Reference line levelwith bottom of centersection spar.

2-7/8" ± 1/8"

Figure 9-5. Strake location references.

___ Prior to cutting the sides of the fuselage and installing the strakes, check the above dimen-sions carefully. Proper installation will result in a -0.5 degree angle of attack on the in-board fuel strake area. This angle of attack is critical in maintaining the proper center of lift.See Figure 9-5.

___ With the fuselage level for-to aft, and side-to side, draw a reference line level with thebottom of the center section spar where it meets the fuselage side. It should go about 78"forward from the aft side of the spar.

___ Draw a parallel line 2-7/8" +- 1/8" above the line drawn in the last step running about 76"- 78" from the aft spar face. This is the centerline of the strake leading edge at its inboardend. Get both sides the same. Check measurement using a water level.

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Note: Due to a change at the factory, there is a discrepancy between the videoand the plans during the following steps. In the past, the strake had thefoam recessed, leaving a lip 4-5" wide running the length of the trailingedge. This is no longer the case. It was difficult to make the recessededge fit parallel to the c-section spar. Now, we do not remove the foam atthe factory. The builder does it, allowing him to custom fit the straketrailing edge to his aircraft. This change applies to both upper and lowerstrakes.

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Figure 9-6. Fitting strake to fuselage.

___ Using a sawhorse, some shims, and a 2 x 4 piece of wood, support the lower strake upunder the spar and support the leading edge inboard centerline mark even with the lineon the fuselage side approximately 76" forward of the aft spar face.

09 - Fuel System


___ You want to have approximately 1" of the strake trailing edge, lapping over onto thewing. This will serve as a fairing, bridging the spar gap. Fashion a pen/pencil to asmall block of wood to bridge the gap between fuselage and strake and guide themarker along the fuselage side marking a cutoff line on the strake. Take small bites asyou cut and try the fitting. Pay careful attention to the outboard edge match with thewings. See Figure 9-6. Trimming is required here.

It is a good idea to place the leading edge of the strake 1/4” aft of theleading edge of the wing. The top strake and glass work on the leadingedge will make up the differance when they are installed.

Before you cut, think of what will be affected; cutting in one place will affectanother place! You want to square up the outboard end of the strake with the inboardend of the leading edge wing root, and get a smooth transition of the strake curve to thewing curve. Keep in mind that the transition match up might change a small bit once thefoam is removed from the trailing edge of the strake.

Cent er sect ion sparSt rake t railing edge

3/8" - ½"

Inner skin

Out er skin

Foam

Out board endLower right fuel st rake

Cut line drawn

3/8 " t o ½" forward of spar

Figure 9-7. Cut line for inner strake skin and foam removal. View is of the right end of thecenter section spar and lower right fuel strake prior to removal of inner skin and foamfrom the trailing edge.

___ Once you are pleased with the fit of the strake, mark a line where the strake meets theleading edge of the center section spar. Pull the strake half, and mark another line,parallel to the first, approximately 3/8" to 1/2” forward of the first.

Sand and cleanfor widt h of st rake

Remove inner skin andfoam for widt h of st rake

St rake out er skinleft int act . Sandand clean.

Bevel foam. Be sure t hat spar will notsit on any foam once st rake is inst alled.

2"

Figure 9-8. Removal of strake inner skin and foam.

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___ Remove the inner skin and foam aft of the second line that you drew, leaving the outerstrake skin intact. See Figure 9-8.

___ Clean up the inner surface of the outer skin with some 80/100 grit paper and someacetone. At the same time, clean and sand the inner surface of the inner skin, up to 2"forward from the edge of the recessed foam.

Lay-up runs full widt h

of st rake t railing edge

Lay-up ext ends f rom st raket railing edge at least 2" forwardof foam cut line.

2 plies coarse BIDat 45º

Figure 9-9. Lay-up over inside of lower strake.

___ Bevel the foam transition so that you do not have a 90 degree bend for the following glasslay-ups to contend with.

___ Place the strake back into position, and check the fit once more. The new edge of thefoam should run parallel to the forward face of the center section spar, about 3/8" to 1/2”forward of it.

___ If everything lines up, pull the strake, and prepare to lay up 2 plies of BID (cut on a 45degree bias) along the length of the trailing edge. Be sure that (1) the foam is beveled, (2)exposed foam is covered with slurry, (3) the strake surface is pre-wet with epoxy.

___ The cloth should be cut wide enough to extend from 2" forward of the edge of the foamback to the trailing edge of the strake (approximately 9" by 48"). Apply the glass, and letcure.

After the proper fit is achieved and all the seams and edges line up, it is time to cut out theside of the fuselage for baggage access.

___ Reinstall the lower strake half, supporting it firmly under the spar with a straightedge. Atthe point where the fuselage and leading edge intersect, support with a sheet metal screwor cleco. A sheet metal screw run from the inside of the fuselage into the foam of the strake(near the leading edge) steadies the strake up nicely.

___ With the strake hanging, sight down the line of intersection between the fuselage andstrake to make sure that it is a nice, constant curve. You do not want any binding againstthe side of the fuselage. Mark the fuselage side where it intersects the inner skin of thestrake. Also, support the strake at the wing root or transfer template with blocks Bon-doed to the roots or the template.

It is to your advantage to get the outboard end of the strake to match the curve of the wingroot as closely as possible. Use clamps, weights, etc. to achieve this. It will save you a lotof work later. Be sure that the two sides are the same.

9.2.4 - Cut out Lower Baggage Access Openings

The forward access openings simply follow the upper skins of the lower strakes. Cutaway the fuselage sides from these areas.

09 - Fuel System


Measure and mark the vertical edges of the rear access openings about 18" forwardof the gear bulkhead and continue to approximately 8” behind the rear door cutout.Later you will trim the front of the opening to follow the contour of the carbon beams.Temporarily install the top strake to get an idea where to cut the top of the cutout. It isbest to cut inside your lines, then file down later.

18“

Back to gearbulkhead

8“

Forward to reardoor cutout

Figure 9-10. Openings for access to strakes.

Figure 9-11. Treatment of access cutout junctions.

___ At this time it is very important to thoroughly sand all the areas where the strake andfuselage intersect as well as where the strake and spars intersect. Proper mating of thesecomponents is very critical. The strakes not only carry fuel and baggage, but they transfertorsional loading into the fuselage (so break out the sandpaper)!

___ In the areas where the outer skins meet strake/fuselage it is necessary to remove primerback approximately 2" to accept the tape glass. On the inner skins of the fuselage, it isnecessary to round the corners slightly so tape glass will conform around the corners. SeeFigure 9-11.

9.2.5 - Lower Strake Half Glassing

___ Make a trial run and get your skins and supports ready for the installation. Makesure that everything fits well and both sides are the same. Notice that the lowerstrake trailing edge extends aft of the center section spar and overlaps the lowersurface of the wing by about an inch with the solid foam core wings. This trailingedge is going to be bonded to both the spar and the wing, and therefore necessi-tates a cut line to allow wing removal.

The strake halves but up to the wing on the Hollow Core wings. There isno overlap.

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Fuselage side (right )

Cent

er s

ect io

n sp

ar

St rake

leadin

g edge

Wing

spa

rFuel st rake(Lower right )

St rake t railing edgeoverlaps t he wing sparapproximat ely 1"

Fuel st rakeleading edge

B

A

Mark a line bet ween point s A and B t o est ablish t he cut line on t he st rake. The line should run parallel t o t hecent er sect ion / wing spar just bet ween t he t wo. The gap bet ween t he CS spar and t he wing spar will be about ¾".

The cut line will run from t he side of t he fuselage t o t he out board edge of t he st rake, allowing removal of t he wing.

Figure 9-12. Establishing strake trailing edge trim line.

The cut will be made following complete installation of the fuel strake system, butnow is a good time to mark where the cut line will go. The cut line will run parallel tothe center section spar and the wing spar, midway between the two, extending from thefuselage side to the outboard edge of the strake. See Figure 9-12. Be careful not to cutthe spar cap when the cut is made!

Forward Aft

Center section spar

Wing

Wing attach points

Strake trailing edgeoverlaps wing sparby approximately 1"

Micro Structural Adhesivewith Cabosil and Flox

Lower fuel strake

2 plies fine BID~ 2-½" wide x 50"

~¾" gap

Cut line through strake - runs parallelto center section spar between spar and wing

Note how foam in strake ends forward of spar. and the gap between spar and foam edge should remain a uniform

¼" to 3/8" for length of the strake.

Foam should never go underthe spar

W ing sp a r

Figure 9-13. Wing / spar / strake junction - cross section.

09 - Fuel System


___ You will need a healthy amount of Structural Adhesive and Cabosil to mate thestrake skin to the center section spar cap and the wing spar cap. EZ- Poxy and Floxmay also be used. Apply the Structural Adhesive to the strake in area below thespars and jig into place. Mound the Structural Adhesive to the center and the front ofthe Spar. If there are gaps at the back they can be filled in when the wing is removed.To hold the strake in position use a section of the aluminum I-beam supplied in yourkit. Cover the top of the beam with duct tape. Screw a wood screw into the side of thefuselage just forward of the firewall and under the center spar. You want it highenough so that it will take a little force to push the I-beam in between the strakebottom and the screw. On the opposite end of the I-beam drill a hole large enough foranother wood screw so you can screw the I-beam up to the wing. At the insideportion of the wind you have a flange that is about 2 inches deep. Drive the woodscrew into this flange. This will hold the aft end of the strake up tight to the spar.

Fuselage side (right)

Cen

ter s

ec

tion

spa

r

Strake

leading edge

Win

g s

pa

r

Fuel strake(Lower right)

Wood screw in side of fuselage

Wood Screw screwed into wing Flange

Figure 9.14 holding lower strake in place with I-beam

___ Lay-up two plies of BID to tie the strake inner skin to the forward face of the centersection spar. The lay-up should run the length of the spar-to-strake contact area. SeeFigure 9-13.

It will be necessary to remove primer in the areas where the outside surface of the strakeintersects the outside surface of the fuselage. Take the primer back about 2" on both thestrake and the fuselage side, then apply a finger radius of Micro along the length of theintersection, Figure 9-13. As shown in Figure 9-11, you should round the inside cornersof the fuselage where it meets the strake to facilitate better surface contact by the fiber-glass that you will be applying in the next step.

All areas of intersection of strake to fuselage (inside and out) get 2 plies of BID tape glassapproximately 2-1/2” wide cut at a 45 degree bias. Check everything and let cure.

It might be advantageous for the builder to be able to differentiate between the upper andlower strakes without having to rely upon the labels alone. Looking at the strake from theoutboard end, you will notice that the upper strake has a more pronounced curvature thandoes the lower strake. Just in case your labels fell off, this might be nice to know.

To fit the upper strake, use exactly the same procedure that you used to fit the lowerstrake skin. Do not force anything and think first before cutting. It will be necessary at thistime to fit the upper half of the fuselage.

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___ First remove the flange in areas where affected and remove the area forward of thefirewall to accept the main spar. It might be helpful to remove small sections of theflange in the nose area to insure proper alignment of outer skins so there will not beany surprises when it comes time to finish the mating line between the upper andlower fuselage halves.

The baggage cutout in the rear is an extension of the lower cutout right up to the innerskin of the upper strake.

___ The sanding and preparation of the upper strake and fuselage is the same as that of thebottom strake.

After fitting the upper strake, overlap the leading edges and cleco together inboard andoutboard of the fuel tank. In the center of the leading edge where the fuel tank is ,use ducttape every inch or two to hold in place while fitting the bulkheads and baffles.

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09 - Fuel System


9.3 - Internal Strake Structures

9.3.2 - Baffles and Bulkheads

___ You will need to glass the 4’x8’ piece of Dyvinicel foam to cut your baffles and bulkheadsfrom. Lay the dyvinicel down on a flat surface. Your glass is only 36” wide so slurry thefoam up to this point. Keep the slurry wet so it will spread easier. Lay one layer of Bidover the top of the slurry and wet out. Make sure you get all the bubbles out under theglass. If you have it is not a bad idea to peel ply this also. Repeat this on the other side afterthis side has cured. You have a roll of baffle and bulkhead templates. Cut them out andarrange them on your 3’x8’ glassed dyvinicel. You will not have much extra. Trace aroundthe templates and cut them out.

Note: To ease in sealing the interior baffles you can add a second layer of Bid tothe inside of the perimeter bulkheads.

___ Fit all baffles and bulkheads to the lower strake first. Mark the exact location of eachpiece on the lower skin before removal.

___ Carefully set the upper skin on and sight through the baggage area or wing root to locateany gaps or interference. Sand or cut to fit. Baffles and bulkheads can be temporarilyheld in place with Bondo or hot glue. I prefer to cut small triangles that are 1” on all sides.Hot glue them to the bottom of you baffles and they act as feet keeping your bafflesupright.

___ Here are some hints when fitting the baffles, and bulkheads:

• With bulkheads temporarily in place, mark them and the strake bottom every 6"or so. Remove the bulkheads and place the strake top onto the bottom. Using atape measure, measure the height at each point and transfer this measurement tothe bulkheads. Connect the dots and sand. You want to have about 3/16" gapbetween the bulkhead and top strake to allow for microglass.

• After you get them close, fit and Bondo one piece at a time in place and keeptrimming it until you get just a little clearance. A good coarse file works well forthis.

• As you fit each baffle or bulkhead, groove the top of the foam to give the microglassthat will be used to bond the top strake (Section 9.3.4) a better grip.

See Figure 9-16 for bulkhead/baffle layout. The baffles are located within the fuel cell.They are installed with one ply of BID tape on each side of the baffle. The function of thebaffles is to prevent the fuel from sloshing and to add rigidity to the structure of the craft.

The bulkheads serve as the boundaries of the fuel cell. These are installed with two pliesof BID tape on each side of the bulkhead and require extra coats of epoxy on the fuelside to seal in the fuel. The bulkheads are installed first and properly sealed before thebaffles are installed.

Note: Do not install the two bulkheads that go back to the spar from the longrear bulkhead (5 and 8) until after the top strakes are installed and therear bulkhead to strake top joint is glassed.

Note: Any modifications to the tank or baggage areas to accept more or less fuelmay affect the C.G. When fuel is added. We do not recommend any changeto the established placement of bulkheads / baffles in the fuel strakes.Careful attention must be paid when calculating the C.G. Shift when fuel isadded and the aircraft is at attitudes other than that of level flight. Thespecifications called for in these plans account for such conditions quitesatisfactorily. If you disregard our warning, please be careful.

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.

. . . Rear fuel bulkhead

. . . Inboard forward fuel bulkhead

. . . Inboard fuel strake bulkhead

. . . Aft interior baffle

. . . Center strake rib

. . . Center baffle

. . . Forward baffle

. . . Outboard fuel bulkhead

Dimensions are approximate, installthe baffles for best fit.

Apply two plies fine BID on both sidesof the vertical and horizontal seams of bulkheads. Finger radius with microglassprior to fine BID lay-ups.

Cut mouse holes at top and bottom ofbaffles for fuel and air flow betweenchambers.

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ce

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rline

Lea

ve ro

om

to a

cc

ess

the

inb

oa

rd w

ing

atta

ch b

olt.

Center section spar

Firewall

15"

7-½"

16-½

"

Ap

pro

xim

ate

ly 3

0"

Bag

ga

ge

are

a

11"

9.5"

8"

Figure 9-16. Fuel baffle and bulkhead location.

09 - Fuel System


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ly B

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ave

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Figure 9-17. Fuel baffle and bulkhead detail.

09 - Fuel System


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9.3.3 - Install Strake Baffles

__ Install all bulkheads before you install any baffles, see Figure 9-17.

In general, the following applies throughout the installation. All patterns are oversize andwill require trial trim fits. While fitting, check the strake to be sure you are not distorting itsshape. Follow the Figures 9-16 and 9-17 for locations in the strake, placement of mouseholes for fuel flow and venting, and lay-ups for glassing in place.

Use two plies of BID at all joints, inside and out, that are part of the periphery. Alwaysapply a good finger radius of microglass at these joints first. One ply of Bid is sufficient tohold the inner baffles .

Note: When you build your fuel tank you will be sealing it either with EZ-Poxy orJeffco. Jeffco is more resistant to odd fuel additives that may be found indiesel fuels. If you decide to use Jeffco you will need two 1 gallon kits toseal your tanks. Also Jeffco cures faster than EZ-poxy so when using Jeffcohave everything ready before you mix your Jeffco.

When sealing bottom strake and baffles apply liberally to all surfaces that are between thefuel and the outside, i.e. the inner strake skin and all surfaces that form the tank or fuelcontainment. Sand these skins and paint them until they are shiny and nonporous. Whenusing Jeffco we apply two coats and we thicken the Jeffco with a small amount ofCabosil. When applying more than one coat apply second coat before the first one com-pletely dries. You want the first coat just slightly tacky to the touch when applying thesecond coat.

9.3.4- Bulkhead Fuel Fittings

Install the fuel gauge fittings (Fitting, 3/8 Elbow, Sight Gauge - Part# VFSG-01) throughthe inboard forward fuel bulkhead, about 4" inside both baggage compartments at the topand bottom. We also carry a clear plastic fuel gauge that is lighted that can be installedinstead.

Figure 9-18. Bulkhead fuel sight gauge fitting cross-section.

___ Drill a 3/4” hole in these locations. Gouge out about 1/4” of foam from between thebulkhead skins. Micro-Glass in the fittings provided with the bottom fittings pointing upat the top fittings and vice versa (depending on whether you are standing on your head ornot). Put BID over the microglass on all fuel lines and fittings on the inside of the tank.

___ Drill a 3/8” hole through the fuselage (both sides) near the rear lower corner of the fueltank for the fuel feed line(s). Gouge out about 1/8" of foam exposing both fuselage skins.EZ-Poxy Micro-Glass a 20" piece of 3/8" aluminum fuel tubing in this hole with smoothbends along the forward edge of the bottom spar cap.

09 - Fuel System


___ Microglass a small piece of stainless steel or brass screen over the hole, inside thetank, cut from a kitchen strainer, or window screen.

Microglass or Flox

Figure 9-19. Fuel line detail.

4"

Center section spar

Strainer

Strainer

Sight gauge elbow

Sight gauge elbow

3/8" fuel line

Baggage to fuel bulkhead

Fuel Vent Hardpoint

Figure 9-20. Fuel and vent lines.

Outboard attach point access hole in lower strake3“diameter

Microglass(4 places)

1x1 1/8“ aluminum harpoint drilled and tapped for 1/4” pipeAN816 fitting

3/8“ hole drilled in side of fuselage

Figure 9-21. Strake vent lines.

09 - Fuel System


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9.3.5 - Fuel system venting

The Velocity uses 3/8” vent lines from each of the three fuel tanks to a commonmanifold at the top of the firewall.

___ Fit your top strake in place and draw a line on the fuselage where it is. Drill a 3/8”hole in the side of the fuselage 8 1/2” forward of the Aft side of the center spar 5/8”down from your top strake reference line. This will put the very edge of your holejust under the top of the strake. Next drill a 7/16” hole in a 1x1 inch piece of 1/8”aluminum. Tap this hole for 1/4 pipe. Using Structural Adhesive bondyour hardpoint on to the side of the fuselage making sure the hole in the fuselage andthe hole in the hardpoint are lined up. After the Structural Adhesive has cured glassover the hardpoint with two bid. When the bid has cured clear the hole in the hard-point using an Exacto knife. Using liquid Teflon or Permatex #2 insert an AN816 -6Dfitting. Repeat for other side.

Aluminum vent lines will have to be made to connect your tank vent to the manifold(AN827-6). Using AN818-6d nuts and AN819-6d sleeves connect your 3003 3/8” alu-minum vent lines to your hardpoints and your manifold. Refer to figure 9-21.

The manifold vents to the outside using a 3/8" aluminum tubing, again joined by AN818nuts and 819 sleeves. Use Adel clamps to hold Your manifold( AN827-6) and your alumi-num lines coming from the fuel tank and also exiting out the bottom.

FuelStrake

FuelStrake

Sump

(1) AN827-6(4) AN819-6(4) AN818-6

(1) AN816-6(1) AN819-6(1) AN818-6

Note: A one way checkValve needs to be installedhere(1) AN824-6(1) AN818-6(1) AN819-6:

(1) AN816-6(1) AN819-6(1) AN818-6

(1) AN816-6(1) AN819-6(1) AN818-6

Figure 9-21. Fuel system vents.

Route lines to avoid low points until reaching the manifold (AN827-6). Avoid any controlor landing gear structures to keep from interfering with their operation.

___ From the manifold (AN827-6). the vent lines run down and out the bottom of the airplanejust forward of the firewall. A one way check valve is installed in this line as shown in figure14-21. This will allow your tanks to vent if your main line ever gets clogged. Let the lineprotrude 3/8” to 1/2” out of the fuselage bottom. Cut off the end at an angle as shown inFigure 9-22. For extra insurance against blockage, drill a 1/8” hole in the aft side of thevent tube.

09 - Fuel System


3/8“ Aluminum Line

Front

Fuselage Floor

Cut at AngleHole inAft SideFigure 9-22. Fuel tank vent.

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09 - Fuel System


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9.4 - Upper Strake Half

9.4.1 - Fuel Cap Installation

___ Install the fuel cap before installing the upper strake. The fuel cap should be installedoutside the prop arc just in case a fuel cap ever came off in flight. Use Figure 9-16 as aguideline to position it centered in the area off of the rear fuel bulkhead, at a high point onthe strake.

Top Skin

2 BIDMicroglass or Flox

Strake top

Aluminum cap housing

4"3-1/2"2 7/8“”

Figure 9-23. Fuel cap installation.

___ Before you start cutting holes measure the dimensions of the caps youhave to be sure you do not cut the wrong size holes.

Using a 4” hole saw, cut through the bottom skin only. Peel off the bottom skin. With a3-1/2" hole saw, drill through the foam only, up to the top skin but not through it. Finally,using a 2-7/8" diameter hole saw, cut through the top skin. Sand the opening until the capfits in the hole from the bottom side and it is flush with the top skin. Bevel away the foamaround the hole to make a nice transition. Sand the skins and aluminum cap housing forgood adherence.

___ Pre-wet the housing and bed into the hole. It is important to be sure there is a completeseal of EZ-Poxy Micro-Glass over the foam to prevent gasoline from seeping into thefoam of the strakes. While it will not hurt the foam, it could eventually find its way some-where to give the impression of a leak. Apply two layers of BID lapping from the bottomstrake skin onto the microglass and cap housing. Let cure. If you use a weight to hold thehousing in place, be careful as to not deform the shape of the strake around the cap.

Note: A composite airplane cannot be bonded through its skin like a metal air-plane can. We have come up with a method to bond the filler caps to theengine. This is an optional step.

Before bonding you aluminum cap ring housing in , drill a 5/32” hole in the flange andcountersink it. You will need about 5 feet on #16 wire for each strake. Crimp a #14-16#8 wire terminal on the end of the # 16 wire. Install an 8-32 countersunk screw in the holeyou drilled and on the back side install your wire terminal and a lock nut. Now you willhave to make a hole large enough for the wire that runs straight back from the hole for yourfuel cap to the center spar. A long coat hanger that has been straightened out works wellfor this. You may also use a long drill but be careful. Now you can bond in your cap. Whenyou do make sure you pack some Micro down the hole with the wire to seal it. Route thewires to your engine and attach them. Now a fueler can ground to your engine whenfueling your airplane.

9.4.2 - Fitting the Upper Strake Half

___ After complete cure of the bulkheads and baffles, reinstall the upper strakes. Use a light toshine through the tank area and check the fit between the baffles and bulkheads and upperskin.

___ Sand or file any high points down to ensure uniform fit (especially at the bulkheads).When you are satisfied, sand all the mating surfaces. Also sand outside the leading edge ofthe lower strake and inside the leading edge of the upper strake where the two overlap.Sand the upper spar cap and all areas where the bulkheads touch the inner skin.

09 - Fuel System


9.4.3 - Upper Strake Half Installation

___ Mark reference lines on the fuselage and wing between the two spars. This willestablish the cut line for the strake (See Figure 9-12). Also mark a line on the fuse-lage where the strake rests. Fit the top strake and drill and install about ten cleco’sboth inboard and outboard of the tank on the leading edge.

___ After the top fuselage is on and before the top strakes are installed, make sure youseal all areas around the gear well, fuselage line, and bulkhead, with a wet two plyBID lay-up.

___ Note: Clean and vacuum the tank area very thoroughly. Any debris leftin the tank will be hard to remove once the top is on. Any remainingforeign material will end up in your fuel system.

___ When using Jeffco you have a limited time to get your top on before the Jeffco starts tocure. We like to take no more than one hour to seal a tank. You need to paint two coats ofJeffco on the top strakes just as you did the bottom strake. The top strake will need to beinstalled before the second coat cures. After you have applied the first coat of Jeffco to thetop strake start to mix your Jeffco to seal your tanks.

While you are mixing the Jeffco to seal the tanks have a partner mix enough structuraladhesive and cabosil to bond the spar to the upper strake. Spread this mixture out alongthe spar cap making sure you get good coverage on the front and middle which will not beaccessible once the strake is on.

The top is sealed with a Jeffco Flox mix that is put on top of the baffles before the tank topgoes on. You cannot mix up one large batch of Jeffco to do the entire tank because itwould start to exotherm before you were finished. It is better to mix two smaller batches.Mix one cup of the hardener to two cups of the resin in a large container. Mix in Flox untilyou get a thick cake icing like consistency. Spoon this mixture into a 1 gallon heavy dutyfreezer bag. Cut the corner off the bag. Using the freezer bag like a cake icing bag , lay abead of Jeffco and Flox on top of all of your baffles and bulkheads. Your bead should beabout 1/2 thick. Also fill the leading edge of the top strake with the Jeffco /Flox mixture toa 1/2” thickness.

___ After the second coat of Jeffco has tacked up get some help and install the upper strake,gently setting it straight down. Avoid sliding the strake so as not to knock any of theJeffco/Flox out of place. Clip the clecos into the leading edge, and check for any voids inthe overlap outboard and inboard of the fuel tank. In between where the clecos are youmay want to wrap the leading edge with long strips of duct tape to hold the top strake halftight to the bottom.

Fue

l bul

khe

ad

Fue

l bul

khe

ad

Insid

e fu

el c

ell

Out

side

fuel

ce

ll

Prior to installationof upper strake

Following installationof upper strake

½"

Upper strake squeezes Jeffco/Flox down and out

Finger radius inJeffco/Flox onthe accessibleside of the fuelbulkhead

Grooves in foam

Jeffco/Flox

Figure 9-24. Joining upper strake to fuel bulkhead and baffle.

09 - Fuel System


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___ Use the same aluminum I-beam you used on the bottom strake along the center spar onthe top. Add some weight to the top of the beam to hold it down. Check the line youinitially put along the fuselage and see where your strake is sitting. If it is higher than the lineyou may put a small weight on it right next to the fuselage in order for it to sit correctly. Donot put too much weight on the unsupported part of the strake because this could perma-nently deform the upper strake.

___ At this time only areas inside the fuel strake and the aft bulkheads inboard in front of thespar are accessible. Use your finger (or a mixing stick) to form a radius with the excessJeffco/Flox. You may also want to duct tape a bent over spoon to a stick to reach into therear of the strake and smooth over the top joint on the rear bulkhead. Do this from insidethe airplane. Let the top strake cure before proceeding.

___ Before attaching the strake to the side of the fuselage, force some microglass down be-tween the strake edge and the fuselage side. Pay particular attention to the area just to therear of the baggage strake where the fuel comes into contact with the side of the fuselage.

___ Tape glass the strake to the side of the fuselage with two plies BID. Tape glass the insideof the baggage compartment with two Bid also. When you are satisfied that everythingthat you can get to is sealed and glassed, let cure completely.

Some visual inspection of the outboard seams can be made through the bolt access coverin the lower strake skin.

___ After cure, remove the clecos in the leading edge. Sand the overlap smooth. Fill thecleco holes with microglass and cover the seam with two plies of BID.

Wing trailing edge

Trailing edgeinboard core

Lower strake trailing edge after cut

Upper strake trailing edge after cut

Fill gaps with micro

Fill gaps with micro

Upper strake

Center sectionspar

Lower strake

Forward

Micro fillets to reinforce strake skin overhang and cover with 1 Bid

Figure 9-27. Separating wing from spar after fuel strake installation.

___ Using a straight edge, connect the marks on the fuselage with the marks on the wings andcarefully cut the wing off. After both upper and lower seams are cut, take the bolts out andremove the wing.

___ The intersection of strake to fuselage can now be sanded and filled with Micro-Balloon.A radius of microballoon can be put in here to achieve a more pleasing cosmetic intersec-tion (See Figure 9-27).

___ After the top strakes are on, you will turn the plane over to glass the spar to strake junctionand the strake to long rear bulkhead junction. Assuming you sanded these areas earlier,the easiest way to do these lay-ups is to wet out the two BID tapes, full length, on a pieceof plastic.

___ Using a wood dowel with a nail sticking out the end, hold onto one end of the plastic whileyou reach in and lay it in place. Pull the plastic off and use a yard stick to press the lay-updown.

___ Refit and install bulkheads 5 and 8, each side, with two plies if BID all around them insideand out if you can reach it.

___ After removal of the wing, the areas in the outboard bulkhead, aft outboard bulkhead, andupper strake are accessible. At this time, check for any voids or gaps in this area, as it isvery rough and rugged. You will have to sand the skins a bit, fill with microglass, and coverwith two plies of BID.

09 - Fuel System


Cen

ter s

ectio

n sp

ar V

CCS-

02

Stra

ke, l

ower

left

VLL

S-02

Lowe

r fus

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lfFo

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Out

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ies

BID.

Lap

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er s

ectio

n sp

ar

and

strak

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ner s

kin.

Out

boar

d en

d str

ake

rein

forc

emen

t:

2 pl

ies

4" x

29"

TRIA

X on

low

er st

rake

and

up c

ente

r sec

tion

spar

.

2 pl

ies

4" x

29"

TRIA

X on

upp

er s

trake

, dow

nin

side

of sp

ar a

nd la

ppin

g ov

er fi

rst la

y-up

by a

bout

thre

e in

ches

Figure 9-28. Outboard and strake reinforcement.

9.3.4 - Outboard End Strake Reinforcement

___ Cut 8 strips of TRIAX 4" wide by 29" long. The major axis should run lengthwise.

___ On the outboard side of the outboard fuel bulkhead, sand a 4" wide strip, roughing up thesurfaces on the upper and lower strakes, as well as on the inside of the spar. Level anyvoids between the spar caps and the strake inner skins with Micro-Balloon.

___ Apply two of the strips along the bottom strake in the sanded area, starting at the strakeleading edge, and extending up the spar shear web.

___ Apply the other two strips to the upper strake, lapping down the spar shear web a fewinches. For increased reinforcement, overlap the lower lay-up with the upper layer by aninch or so at the strake leading edge.

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09 - Fuel System


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9.5 - Sump Tank and Fuel Lines

9.5.1 - Fuel lines

The XLFG comes to you with a premolded sump tank.The tank has hardpoints installedfor the main tank inlets. You must install the hardpoint for the drain, outlet to engine and thevent.

Inst

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int (

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X 4"

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.25"

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1"Fr

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AN82

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Low

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Send

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Ven

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e

Lines

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om S

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s

Figure 9-29. Sump tank installation.

___ Drill the pre-installed hardpoints to 7/16 and tap for 1/4 pipe. Remember, pipe thread orNPT are entirely different from standard threads.

___ Install 1-1/4” x 1-1/4” x 1/4” aluminum hardpoints for the tank drain , vent and the outletto engine. The tank drain hardpoint should be on the bottom of the tank centered 1/4"back from the forward edge of the tank. The vent hardpoint should be as high as you caninstall it in the tank. The outlet to the engine should be centered in the tank 1” above thebottom. The outlet will be installed on the tank cover. Micro-Glass the hardpoints inplace, create radius / taper around aluminum to keep glass from bubbling up. Cover withtwo plies BID.

___ Drill an 11/32” hole in the drain hardpoint and tap it for 1/8 pipe. Drill a 7/16” hole in thevent hardpoint and engine outlet and tap them for 1/4 pipe.

09 - Fuel System


___ Optional: You can install a low fuel sender in your sump. This will turn ona light on your panel when the fuel level in the sump starts to drop. Thehardpoint for the sender is drilled and tapped and comes with the sender.Drill a 3/4 inch hole in the front of your sump 1-1/2” below the top. UsingMicroglass and 2 bid attach the hardpoint like the others in the sump.

9.5.2 - Install the Sump Tank Cover

___ Cut out the cover to fit the front of the tank. Clean the inside of the tank and cover,MEK works well, and sand again to eliminate hand prints, etc. Paint the inside of thesump tank and cover liberally with as many coats as it takes to make the surface shinywith no fabric weave showing. Let cure and inspect it again. Repeat if necessary.

___ Sand a full 1" margin around the outside front edges of the tank and cover. Applysmall bead of Micro-Glass to the edge of the tank. Put the cover in place and apply 2plies of BID with a liberal amount of epoxy. Let cure.

___ Clean and sand the outside completely as you did the inside. Paint the outside repeat-edly for a shiny, weave free, finish.

9.5.3 - Install Mounting Tabs

___ Cut four 3" x 4" pieces of TRIAX, axis long, and four 3" x 4" pieces of BID.

___ Pre-wet two plies at a time on plastic. Lay plastic on a flat surface that is about 6" widerthan the sump tank.

1.5“

2.5“”

Sump tank

2 plies TRIAX

2 plies BidForward

AN3-10AFigure 9-30. Sump tank mounting tabs.

___ Sand rectangles in the vertical center of the tank on the sides and back.

___ Apply two of the 2 ply bid pads on the back of the sump tank, horizontally, lapping 2.5"onto the back of the tank and letting 1.5" extend out as a tab. Lay the tank down on theplastic covered surface, back side down, and smooth the tabs straight against the plastic.

___ Apply the other two 2 ply triax pads onto the sides of the tank, aligned with the abovepads, lapping 2.5 " onto the tank sides and 1.5" onto the above pads, forming a 4 ply 1.5"x 3" mounting tab.

9.5.5 - Sump Tank Installation

The sump tank is positioned centered in front of the gear bulkhead.

___ In this position, drill (4) 3/16" holes (2 per side) and bolt to the gear bulkhead withAN3-10A bolts and large area washers.

___ Once the sump is fitted into place, a hole must be drilled through the bottom of thefuselage to facilitate access to the sump drain.

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09 - Fuel System


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9.6 - Wing Strake Cutout

9.6.1 - Wing Strake Cutout

The strakes of an XL are 76" from the trailing edge of the main spar at the side of thefuselage. The leading edge is 2-7/8" +- 1/8" above the bottom of the main spar.

The cut you made earlier in the strake area of the fuselage went from the rear fuel bulkheadforward to within 8" of the door line.

___ After the top strake is installed, make a mark on the leading edge of the strake outboard ofthe fuselage, using a square held along the fuselage at the strake door intersection point.Another reference point for this is 30" from the intersection of the fuselage join line and thedoor line mark on the fuselage. If the forward position of your strake is more than 76"from the rear side of the main spar, that 30" measurement will not be enough. This will beyour reference point for your cut template.

76"

30"

Point A

Bottom view

Fuse

lag

e s

ide

Cut line(use template)Measured to middleof strake leading edge

Point A

Fuselage join line

Door/strakeIntersection

Square

Figure 9-27. Strake cutout for door.

___ Copy the paper template labeled “Strake Slice Template” you received with your kit to athin piece of plywood veneer or stiff cardboard. Place the L.E. Point of the template at the30" mark, aligning the back edges of the template with the door cut line above and belowthe strake. Some trimming of the template may be required for your particular installationto get a good fit. Use a marker to mark this cut line. This gives you a straight cut throughthe strake.

Note: Before you make your cut double check the position of your front fuelbulkhead. If you installed your bulkhead too far forward you can moveyour cut line further forward to insure you do not cut into your fuel tank.

___ Cut the front section of the strake off now and try and cut as if you were slicing it off at acontinuous angle. Now you have access to the whole door line.

09 - Fuel System


9.6.2 - Wing Strake to Beam Support

___ With your beams installed, you can now cut the rest of the fuselage away in the wingstrake area right up to the beams. Be very careful not to cut into the beams.

Its a good idea to cut within 1/8" then file or sand to the beams.

Fuselage

Carbon beam

Fuel bulkhead

4 plies UNI

¼" foam bulkhead

Forward

Top view

Storage

Door opening

Figure 9-28. Strake to beam support.

___ Using the template provided, make two 1/4" (or 3/8") foam bulkheads. These bulkheadswill mount flush with the rear side of the beam and extend perpendicular from the side ofthe fuselage, out to the inside bulkhead of the fuel tank.

___ In order to keep this bulkhead following flush with the beam, you will need to heat thefoam up with a blow dryer and do some shaping. Sand the area around the bulkhead, foreand aft, wing strake and fuselage.

___ Sand the rear side and inside surfaces of the beams. Install this foam bulkhead with hotglue or Bondo, (small dabs). EZ-Poxy Micro-Slurry the foam as normal procedure, andapply thicker Micro-Balloon to form a radius in all the corners of the bulkhead.

___ Pre-wet the beams beside the bulkhead. Apply 4 layers of UNI, orientation horizontal,from the forward bend in the beam, across the inside surface, around to the rear surface,and across the rear side of the bulkhead, onto the inside fuel bulkhead about 1-1/2". Youmay also be lapping onto the wing strake surfaces an inch or so.

___ EZ-Poxy Micro-Slurry the forward side of the foam bulkhead, radius the corners, andglass the bulkhead with two plies BID. Make the pieces big enough to lap onto thefuselage and strake surfaces. If it is not big enough just use glass tapes to attach it to thestrake surfaces.

___ Cut a piece of 1/4" dyvinicel foam, that will fit into this area that you just relieved. Makesure that it is flush with the surface so it does not hinder closing and glue in place with 5minute epoxy. Relieve some foam from the outside edge around next to the outside skinwith some 36 grit sand paper. Flox or Micro-Glass the edge, Micro-Slurry the foam,and glass with one layer of BID on each side.

___ After cure, remove the door. On the fuselage (strake), you have exposed foam all aroundthe opening.

There are two ways of dealing with this area. First, you can just remove some foam as youhave done many times before, all around the foam to outside skin junction and inside skinto foam junction. Fill this void with flox or Micro-Glass and glass over with one layer ofBID.

We prefer to make a pocket using some cured glass sheet (4 BID) about 3" high that fitflush with the edge. Hold the piece of glass up to the strake and trace around the edges.Cut the sheet so your part will fit just inside the strake. Hot glue the piece in place andcover the edges of the strake and your part with one layer of BID.

09 - Fuel System


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9.6.3 - Installing Leading Edge of Strake onto Door

___ Clean up the cut off section of the strake so that it is straight and smooth.

___ Close and latch the door. Hot glue some pieces of a mixing stick around the front ofthe cut off section of the strake. These are just used for spacing.

___ Clean up the mating edge of the front section of the strake. Put it in place and checkthe fit. You can space it out from the fuselage if you need to, or take some away, inorder to get it to fair in properly.

___ When properly fit, mark the outline of the piece onto the door. Remove the leadingedge and remark the line about 1/2" inside the other line. Also, mark the approximateposition of the door stiffener onto the outside surface. Cut this section out of the door,making sure you do not cut into the stiffener. You should be flush with the insidesurface of the stiffener.

___ Sand all around the strake leading edge and door where it will bond in place. Repo-sition the leading edge and tack in place with 5 minute epoxy. Micro-Balloon radiusaround to match the rest of the strake, and glass with two plies BID. Micro-Balloon aradius around the inside of the strake leading edge and glass with one ply BID.

___ Open the door and remove the first 3/8” or so of inside glass and foam around theopening of the strake that is attached to the door. This is the area that faces the otherpart of the strake.

09 - Fuel System


9.7 - Fuel System Plumbing

9.7.1 Solid fuel line Installation

In your kit you received 18 feet of 3/8” 3003 aluminum tubing. This will be used to plumbyour fuel system. In the engine install section we go in depth on how to flare tubing. Youwill need to get a flaring tool that will do 37 degree flares. There are automotive flaringtools that do not have the correct degree of flare, so make sure it is an aircraft flaring tool.You will also need a tubing bender that will accommodate 3/8” tubing.

Thread on AN fittings does not always stop at the same place. You may screw in one fittingand it points directly up when tight but the next fitting may be pointing directly down. If youcan’t get a fitting tight and pointed in the right direction try another one.

Be careful when bending your tubing. You do not want to kink or put a flat spot in yourtubing. If you do this will affect the flow of the fuel. If you are not sure about a bend startwith a smaller bend. You can always bend a little more but if you try to straighten bends thisis when you kink tubing.

Figure 9-29 gives you the routing of the fuel lines as well as the fittings used.

FuelStrake

Fuel Strake

Sump(1) AN822-6(1) AN818-6(1) AN819-6

(1) AN822-6(1) AN818-6(1) AN819-6

(1) AN822-6Fitting to engine(1) AN832-6D Firewall fitting

(1) AN924-6D nut(1) AN818-6(1) AN819-6

(1) AN818-6(1) AN819-6

Figure 9-29 Fuel Line Routing

fuel system - velocity aircraft · 09 - fuel system january 2005 09-xlf ... 9.7.1 solid fuel line...

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