AH-1F COBRA 600 - Approach Engineering engineering proudly made in the usa ap101 ah-1f cobra 600

APPROACH ENGINEERING WWW.APPROACHENGINEERING.COM

PROUDLY MADE IN THE USA

AP101

A H - 1 F C O B R A 6 0 0

AH-1F COBRA 60 PAGE # 2

APPROACH ENGINEERING AH-1F 60 MECHANICS

1.0 Purpose

To establish a process that ensures control and standardization in the manufacturing of AH-1F Cobra for use with 60 size mechanics. P/N AP-101.

2.0 Tools Required

Note: (A) denotes tools required for assembly and (T) denotes tools required for testing.

Basic Hand Tools (A, T)

Epoxy 30 Minute, JB WELD (A)

Cyanoacratulate (CA) (A)

3.0 Reference Documents

Plans for AH-1F Cobra Plan Sheet (A, T)

4.0 Attachments

5.0 Introduction

1. WARNING This aircraft is not a toy. It is capable of serious bodily harm and property damage. Every precaution must be taken to properly build this kit and install all radio components. It is your responsibility alone to ensure all safety steps are taken outlined in the Academy of Model Aeronautics safety codes. If this is your first time building a aircraft kit it is highly recommended that you find experienced help for the first flights. Consult your local hobby shop or write to the AMA for further guidance. Academy of Model Aeronautics 5151E. Memorial Drive Muncie, IN 47302 (800) 435-9262

2. Please inspect all parts before building. If any parts are broken or missing please feel free to call or write for replace-ment. All instruction manual photos are included with the CD along with other scale documentation pictures to ease in finishing. If a step or photo appears unclear to you inspect the CD for additional photos with different views to aid in assembly If you have any questions, comments, or improvements please call or write to: Approach Engineering LLC Ridgecrest, CA. 93555

3. We as manufacturer can provide you with assistance and a top quality kit and instruction manual. When built light, straight, and true you will have a model that flies as well as it looks on the ground. However the finished product de-pends on the quality built into it. We can not guarantee the flight performance. Take your time and read all instruc-tions carefully before and during construction.

4. During the assembly procedure the use of the term CA refers to thin CA glue and CA+ refers to medium viscosity glue.



6.1 Assemble the side frames, (S-1, S-2, S-3, S-4) over a piece of wax paper. Refer to the full size plans and the included pic-ture for assembly. Punch out the four 3/32” fuselage side pieces for each side. The provided tabs allow for proper alignment and assembly of the fuselage sides. Build a right and a left taking note of the triangle stock reference lines. These will aid in the installation of the triangle stock. Using the notches provided assemble and glue with CA the two fuselage sides.

6.2 Place the completed assemblies of the fuselage side frames and lay them out to build a right and left half. Have the triangle reference lines up so that they will be on the inside of the as-sembly. The notches in the fuselage for F-3 and F-4 will line up with the notches in the fuselage doublers. Using 30 minute ep-oxy glue on the fuselage doublers. Set aside and allow to dry.

6.3 Take note of the laser labeled 3/4” triangle stock reference lines on the inside fuselage surface. Cut and glue with CA the 3/4” triangle stock to match the reference lines. Complete for both left and right sides.

6.4 Glue F-3, with the text and curved edge, and F-4 into the notches of the fuselage doublers to make the fuselage box.

6.5 Glue 3/4” balsa triangle stock along the lower edge in front of F-2 so that it extends past the front of the fuselage sides by about 1/8” to be sanded off later. To aid in bending you may want to saw cuts down to about 1/8” from the fuselage side.

6.6 Punch out former F-1 from the 1/8” light ply. Using CA glue to the front of the fuselage so that the notches fit in the fuselage sides. Sand the triangle stock flush with F-1.

6.0 FUSELAGE ASSEMBLY

Align Notch Openings

F-3

F-4

3/4” Triangle Stock

Saw Cuts

Notches Sand Flush

3/4” Triangle Stock



6.7 Punch out the 1/8” Light ply former F-2. Glue it behind F-1 so that it is flush with the canopy edge.

6.9 Glue with epoxy the 1/4” light ply fuselage base so that it is lined up with the back end of F-4 and front of F-3.

6.11 Punch out the 1/8” light ply transmission back plates and canopy backer plate. Sand the outside corner edge to relieve the corner so that the transmission and canopy will slide in easier. Making sure not to get glue inside the canopy teeth area glue TBT so the notch lines up with F-4. Glue the CBT in front of the transmission backing. Complete for both sides.

6.8 Turn the fuselage assembly over. Using epoxy glue the 3/4” square hardwood landing gear blocks into the notches of the fuselage doublers. The holes in the fuselage side should line up with the landing gear mount holes.

6.10 Punch out the 1/8” light ply FD-2. Using CA glue in front of F-2 and notched into F-1. Complete for both sides.

NOTES:

6.0 FUSELAGE ASSEMBLY

FD-2

TBT

CBT



7.1 Punch out the two 1/8” lite ply vertical fin supports and two tail rotor tube supports (TSR) and one trailing edge former (TE-2). The rounded edge of the tail rotor tube support faces fore-word. Glue TE-2 in the upper slot and the two TSR supports in the mid and lower slots.

7.3 Glue ¼” triangle stock to the inside edge of the vertical fin supports and the tail rotor frame base.

7.5 Roughen the tail rotor tube surfaces with sand paper to increase the strength of the glue bond.

7.2 Glue the vertical fin assembly into the tail rotor frame base (TFB).

7.4 Referring to the plans for proper placement, glue in the tail rotor drive shaft tube supports at 5.2” and 2.5” inches from the bottom of the tube. The last support will be flush with the bot-tom of the tube. Mark up a scrap piece of balsa at the correct dimensions to help insert the supports at the right distances.

7.6 Using epoxy glue the tail rotor tube so that the bottom sur-face is flush with the lower surface of the bottom tail rotor tube support.

7.0 VERTICAL FIN ASSEMBLY

Flush with lower surface



7.7 Trial fit the leading edge supports (TSF) to ensure proper fit and contact with the tail rotor tube. Using epoxy, glue the tail rotor leading edge supports in the notches and to the tail rotor tube.

7.9 Apply epoxy to the inside surface of the tail rotor drive shaft supports. Slide the tail rotor drive shaft starting from the bottom up to the top surface of the upper drive shaft washer.

7.11 Apply ¼” triangle stock along the edge of the lower sur-face of the tail rotor frame to the fuselage sides. Do not have the triangle stock extend past the 3/4” triangle stock.

7.8 Slide the tail rotor pushrod outer housing through the holes in the leading edge supports so that it so that it extends past the upper leading edge support. You can trim later as necessary to fit your control linkage setup.

7.10 Glue the tail rotor tube assembly to the fuselage assembly by aligning the notches in the fuselage sides. Trim the triangle stock as necessary to clear the pushrod tube.

7.12 Make two sets of the tail boom filler blocks by gluing two (FBS) together. The tail boom filler blocks are made to fit on the lower surface and back side of the tail rotor frame for extra support and the outer profile will match the fuselage pro-file. Using CA glue flush with the lower tail rotor frame sur-face, back side of the tail rotor frame, and fuselage side surface.


TSF

Align in the notches

2 Sets of 2



7.13 Sand the tail filler block middle (FBM) at a angle and trial fit to the remaining gap in the tail boom end. The block should be tapered to a edge on the trailing side and the full ¼” on the leading side.

7.15 Using the 3/32” x 6” wide x 12” long balsa, cross sheet the remainder of the lower tail boom starting from the ¼” light ply base to the end of the tail boom. Note: make sure not to build a twist into the tail boom as you apply the cross sheeting.

7.17 Sand the horizontal fin to the desired shape. Note: the real aircraft has a flat top and a rounded lower surface. This may pull the nose up in foreword flight and it is up to the mod-eler which shape to sand.

7.14 Glue the tapered filler block into position when properly fitted in place.

7.16 Making two sets glue the upper and lower horizontal fins together, from the ¼” balsa, making sure to make a right and a left.

7.18 Glue the ¼” x ¼” x 7” spruce in the notch of ONE of the horizontal stabilizers.


Tapered Edge

Leave 1/4” thick on this end

Filler Block



7.19 Note: depending on your desired finishing technique you may want to omit permanently gluing the horizontal fins on at this time to aid in sanding and finishing. Slide the spruce notch in through the holes and have the fin tab notch fit in the side of the fuselage. Trial fit the other fin and when satisfied glue with CA+.

7.21 Assemble the servo mounting rails by punching out the two 1/8” light ply supports labeled Approach Engineering. Pull out the two 1/4” x 1/2” spruce servo rails and slide into place. Do not glue at this time until you have properly fit the assembly.

7.23 Punch out the 1/4” balsa pushrod support. Glue the sup-port to the pushrod outer tubing so that it properly lines up with your servo position. Using scrap balsa properly secure the re-mainder of the pushrod tube to the lower and side surfaces so that there is as little movement as possible.

7.20 Glue ¼” by ¼” by 3” balsa along the tail rotor drive shaft tube to the lower sheeting. Make sure to align the drive shaft as straight as possible. Apply glue between the supports and the tail rotor drive shaft.

7.22 Slide the assembly just behind F-4 between the fuselage doublers and sitting on top of the 3/4” triangle stock along the lower surface. Temporarily install a servo to help determine proper pushrod placement.

7.24 Punch out the 1/8” light ply former F-5. Trial fit into place behind F-4 in the transmission area. This is used to square up the tail and to make more rigid. Fit in place with the “Front” text facing toward the front of the aircraft. Fit into notches and make sure it is flush with the upper fuselage edge. in the fuselage side and glue in place.


Scrap Balsa

Pushrod Support

Notch



8.1 Sand the face of the fuselage assembly flush with F-1. Glue on the two TSU back plates (TSU-B) together. Position the notch toward the bottom of the fuselage and glue flush with the bottom and sides of the fuselage nose.

8.3 Glue the two TSU bottom pieces, TSU-L, together. Mark a line 1/2” from the back edge as a sanding guide. Sand the TSU bottom pieces from the line at a constant angle to about 3/32” up from the rounded edge as shown in the picture.

8.5 Glue the five nose blocks together starting from NB-1 on the bottom to NB-5. Make sure that the back edge is flush and forms a block. Glue the assembly to the top of the TSU back plate against F-1. Sand the nose blocks flush with the top of the cross sheeting on the fuselage nose. Sand a small radius on the front of the nose block and the sides flush.

8.2 To aid in sanding draw lines on the lower surface and the fuselage side ¾” from the sheeting. When sanding make a even transition from line to line. Sand the fuselage corners to their finished rounded shape. Sand rounded corners on the three out-side edges of the TSU back plate.

8.4 Glue the TSU bottom pieces into the notch in the TSU back plate.

8.6 Make two sets of three T-2’s glued together. Sand the front of the TSU to the desired finished rounded shape by rounding the corners. Glue one T-1 between the two TSU as-semblies and one T-3 on each side and sand the glued assembly to the desired finished shape.

8.0 NOSE AND TSU (TELESCOPING SIGHT UNIT) ASSEMBLY

Fuselage Bottom

Back Edge Flush

3 T-2’s

T-1 T-3

T-3



9.1 Punch out the 3/32” balsa canopy sides and the 1/8” lite ply canopy guide teeth (CGT). Lay out the parts to build a right and a left canopy side. Position the canopy guide teeth so that the teeth extend past the bottom surface and match the bend with the sides and equal 1/8” from ends. Glue with CA. cut 1/4” triangle stock (TRI-4) to fit between C-1, C-2, and C-3. Line up the triangle stock with the printed reference lines.

9.3 When the glue has dried run a bead of glue up the remain-der of C-1, C-2 and C-3. Using masking tape pull the canopy sides to conform with the curve of C-1, C-2 and C-3. Sand the top of the triangle stock flush with the canopy sides for cross sheeting.

9.5 Carefully cut out the canopy top surface CT-1 from the 3/32” balsa. Glue on the top surface so that the front edge lines up with the bend in the center canopy. Sand the canopy surface flush with the center canopy surface.

9.2 Starting at the base, glue only 1” up on both sides of C-1, C-2 and C-3 to the fuselage side and guide teeth. This will help to build a straight canopy by first assembling it as a “box” struc-ture.

9.4 Turn the canopy over and glue C-4 into place in the notches in the canopy guide teeth. The bottom surface should be flush with the edge of the canopy guide teeth.

9.6 Cut out the canopy center section CT-2 and complete the step as earlier. Sand the front and rear edges flush as before. Cut out the front canopy edge, CT-3 from the 3/32” balsa. Align the front edge with the front of the canopy. Glue in place

with CA. When set sand the back edge flush with the top surface of CT-2.

9.0 CANOPY ASSEMBLY

Triangle Stock extends past upper edge.

Sand Flush

C-4

Sand this edge flush

CT-2

CT-3



10.1 Punch out the 3/32” transmission sides and the 1/8” lite ply transmission guide teeth (TGT). Making sure to build a left and a right side, position the guide teeth so that the inside line of the guide teeth line up with the bottom of the transmission sides (detail A). The back edge (detail B) and the front edge (detail C) will be lined up with the transmission side edges. Using CA, glue the guide teeth along the bottom edge of the transmission sides.

10.3 Glue 1” of the lower surface of E-1 to the transmission sides. Glue the ¼” transmission sub base, TSM, to the upper rear of the transmission sides. Once square, glue the remaining sides of E-1 to the transmission sides.

10.5 Punch out the ¼” transmission mid blocks and trans top and glue each set together making sure to have both ends la-beled back together. Glue with CA.

10.2 Cut and glue 2” long by 1” triangle stock to the upper edge of the transmission sides just in front of the intake open-ings.

10.4 Turn the transmission assembly over and apply 1” trian-gle stock to the edge of the fuselage sides and the transmission sub base.

10.6 The transmission sub block will aligned with the back edge of the transmission sub base. The transmission sides must be pulled out to match the edge of the transmission mid block assembly. Glue to the upper surface of the transmission assem-bly. Position the trans top blocks directly over the mid blocks and glue in place with CA.

10.0 ENGINE AND TRANSMISSION BAY ASSEMBLY

TSM

E-1

1” Triangle Stock

Trans Mid Blocks

Trans Top Blocks

C B

A



10.7 Cross sheet the remainder of the transmission top with 3/32” balsa. There are 3/32” x 6” x 12” sheets included for the sheeting.

10.9 For ease of sanding the intakes must be shaped prior to gluing to the transmission assembly. Using intake template 1, from the provided sticker paper, shape the front of the intakes. Apply the adhesive template to both sides of the intake and sand the intake to the template shape.

10.11 Using intake template 2 apply to the rear end of the engine cowling side. There should be a 1/8” edge left on the rear of the cowling side. Sand the cowling side to match the profiles.

10.8 Making sure to build a left and a right engine intake posi-tion the ¼” intake sub mounts (ESB) on the ¼” intake sides. Glue with CA.

10.10 Sand the center portion of the intake to a rounded shape. Only sand the edge between the intake sub mounts.

10.12 Apply the intake template 3 over the supplemental air intake on the cowling sides. This is a template to aid in sanding the intake angle. Sand a flat surface to the inside edge.




10.13 Flip the assembly over and apply the same angled sur-face on the inside back edge of the supplemental intake.

10.15 Glue the cowling sides to the transmission assembly.

10.17 Sand the upper surfaces of the transmission assembly to the desired rounded finished shape. Use the provided picture below and the pictures provided on the disk to aid in sanding to the finished shape.

10.14 Sand a rounded profile along the lower edge only of the cowlings.

10.16 Glue E-2 on the back of the transmission assembly us-ing the provided notches. Mark the profile that it will create on the back surface. Mark the line 3/32” outside E-2 to account for the cross sheeting that will be applied later.

10.18 Temporarily install the transmission bay assembly onto the fuselage. Using the 3/32” x 6” x 12” balsa, cross sheet the top of the tail boom starting behind the notches in the fuselage side. The sheeting will go all the way around the vertical fin and on top of the tail boom fillers.


Sand Lower Edge Only

Start sheeting at notches

Sheet behind the vertical fin



10.19 Keeping the transmission assembly. Punch out the 1/8” light ply exhaust mounts, EXM, and exhaust former E-3. Using the provided notches fit the mounts and former together to achieve the required angle of E-3. The rounded surface of the mounts should face up. Glue with CA.

10.21

10.23. Notes:

10.20 Apply the doghouse template to the top of the transmis-sion by putting the tip of the template 3-1/2” from the back edge of E-3. Punch out the 3/32” doghouse templates, DH-1, and glue around the template on the top of the transmission bay.

10.22

10.24 Notes:




10.25 Cut out the bottom edge of the vacuum formed dog-house to match the profile of the upper surface of the transmis-sion assembly

10.27 Carefully cut out the two transmission guide edges, DH-1, from the 3/32” balsa sheet. Using CA+ glue just inside the line marked on the previous step.

10.29 Glue the doghouse on the top of the transmission as-sembly using CA+. Punch out the 1/4” balsa doghouse top and position it over the doghouse. Draw the inner circle location onto the vacuum formed doghouse and cut out.

10.26 Place the trimmed doghouse on the transmission assem-bly and trace the outside contour onto the transmission.

10.28 Using a knife, razor, or Dremel cut out the material between the doghouse edge pieces. Trim away any excess balsa inside the transmission assembly.

10.30 Sand the doghouse top to the finished rounded shape and glue in place.




11.1 Punch out the 1/8” lite ply wing spars and the 3/32” wing ribs W-1, W-2, and W-3. Assemble them according to the plans and glue the ribs to the wing spar. Glue on the ½” leading edge stock centered on each wing spar leaving 3/32” on the upper and lower surfaces for sheeting.

11.3 Apply CA to the wing ribs and wing spar. Bend the cross sheeting over to match the contour of the wing ribs. Note: wetting the wood will aid in bending. Sand the cross sheeting trailing edge to match the wing rib contours.

11.5 Apply CA to the wing ribs and wing spar. Bend the cross sheeting over to match the contour of the wing ribs. Note: wet-ting the wood will aid in bending. Sand the cross sheeting trail-ing edge to match the lower wing surface. Sand the leading edge to match the upper and lower wing sheeting and round to desired shape.

11.2 Using the laser cut 3/32” lower wing sheeting, sand a small angle to the leading edge to match the angle of the leading edge. Apply CA to the front of the sheeting and glue to the leading edge.

11.4 Using the laser cut 3/32” upper wing sheeting, sand a small angle to the leading edge to match the angle of the leading edge. Apply CA to the front of the sheeting and glue to the leading edge.

11.6 Apply epoxy to the wing root surface. Slide the protrud-ing end of the wing spar into the slot in the fuselage side and glue in place. Depending on finishing techniques you may want to wait until later to glue in place.

11.0 WING ASSEMBLY



11.7 From the inside apply ¼” triangle stock to the edges of the wing spar for increased strength. Note: picture shows wing after a painted state for desired finishing technique.

CONTINUE TO NEXT SECTION.

NOTES:

11.0 WING ASSEMBLY



12.0 Rocket launchers can be assembled with 7 or 19 missile tubes … We supply both Ply Ends for these so make sure to choose one or the other depending on the model you are build-ing.

12.2 Punch out the 1/8” lite ply rocket launcher stabilizers (RLS) and the ¼” balsa rocket pylons. Make two sets of two rocket launcher pylons.

12.4 Punch out the 1/8” lite ply rocket stabilizers, RLP, and glue in the provided slots. You may glue the rocket launcher tubes to the stabilizers at this time depending on your finishing technique. It is recommended that you finish the pylons and tubes prior to gluing.

12.1 Punch out the 1/8” lite ply rocket launcher faces. Glue in each face flush with the rocket launcher tubes. You need to make sure that the faces are properly aligned to minimize tube twist.

12.3 Sand the rocket launcher pylons to the desired finished shape.

12.5 Notes:

12.0 ROCKET LAUNCHER ASSEMBLY



13.0 Punch out four ¼” balsa wing tips (TLS), and two ¼” balsa wing tips centers (TLC). Glue one balsa wing tip center on each side of the wing tip center. Make two launchers total at the same time.

13.2 Slide the 1/8” tow supports into the slots of the wing tip assembly. Glue in place with epoxy to allow you time to prop-erly position the supports.

13.4 Pull out the smaller TOW tubes and slide them into place. Run a small bead of CA along the inside edge of the tube and allow to dry.

13.1 Sand the wing tip assembly to the desired finished shape.

13.3 Glue the 1/8” tow holders on the notches on the front of the TOW assembly.

NOTES:

13.0 TOW LAUNCHER ASSEMBLY



14.1 The 20mm gun can be made to rotate with the use of a servo. Parts are included for this option. Punch out the 1/8” lite ply gun base, gun side supports, and gun supports. Glue the gun supports into the notches of the gun base.

14.3 Prepare the three ¼” diameter wood dowels by drilling a 3/32” hole in the end. The barrels then need to be tapered. One easy method is by putting the back end in a drill bit and spin-ning it while a helper sands it.

14.5 Glue the three barrels into the gun base so that the ¼” dowels are flush with the ends. Punch out the front and middle barrel support from the 1/8” ply and slide into place. Use a small amount of CA to glue in place. Paint and finish the gun turret to finished appearance.

14.2 Using 1/16” balsa, cross sheet the gun supports. Run the grain perpendicular to the gun side supports. Use a small amount of water to wet the balsa to aid in bending.

14.4 Glue in the gun side supports in the notches in the gun base. Slide in the ¼”diameter balsa sticks into the hole of the gun side supports and sand flush. Punch out the two ¼” balsa gun chin blocks (GCB) and glue together. Sand the chin blocks down to a feather edge on one side in order to achieve the proper angle.

14.6 Referring to the plans position the gun chin blocks to the lower nose cross sheeting and mark the position. Glue the feathered down balsa gun chin blocks to the bottom surface. Using a 5/16” drill bit or knife, cut out the bottom sheeting through the provided hole in the gun chin blocks.

14.0 20mm CANNON ASSEMBLY



14.7 Punch out the gun mount support block, GSB. Align the hole with the hole created from the balsa gun chin blocks and glue to the bottom inside surface of the nose cross sheeting.

14.9 This step should be completed after finishing and paint-ing the fuselage and gun. Slide the gun assembly up through the hole. Slide the spring over the wood dowel. Using CA+ glue the 1/8” ply gun control horn (GCH) over the dowel.

NOTES:

14.8 Glue the 5/16” by 1.5” wood dowel into the top of the gun assembly. The dowel should be inserted all the way to the top of the ¼” barrels.

14.10 There is a coiled Spring in the kit. This goes between the wood servo arm and the floor to keep the gun from sliding down.

14.0 20mm CANNON ASSEMBLY



14.11 Glue the 1/8” lite ply vertical fin trailing edge former TE-1 into the slots provided.

14.13 Cut the ¾” balsa triangle stock leading edge to match the upper tail boom cross sheeting and the top leading edge sup-port. Glue the leading edge to the cross sheeting and the leading edge supports.

14.15 Wet down the vertical fin sheeting to aid in bending and let it soak in for a minute. Apply CA+ to the tail boom supports and trailing edge formers and bend the sheeting into place. The sheeting will overhang past the end of the trailing edge formers. Once the glue has dried sand the sheeting to match the other sides profile.

14.12 Trial fit the transmission assembly on the fuselage. You will note that the tabs on E-2 extend down the side of the fuselage sides to keep the surfaces matched. Cross sheet the upper surface of the tail boom using 3/32” balsa starting from the notches by the transmission to the end of the tail. Note: The cross sheeting goes underneath the trailing edge former, TE-1.

14.14 Using 1/16” balsa laser cut vertical fin sheeting (VFS), sand the leading edge to match the triangle stock for a better fit and glue bond.

14.16 Repeat step 14.4 and 14.5 for the other vertical fin side. Sand the upper edge flush with the leading and trailing edge supports.

14.0 VERTICAL TAIL ASSEMBLY

TE-1



14.17 Sand the ¾” balsa triangle stock leading edge to the desired final shape.

14.19 Using a ½” square balsa stick, round the top corners and run from the vertical fin leading edge to the transmission back for the tail rotor drive shaft cover. A tip to aid in sanding the drive shaft cover to the right shape is to wrap sandpaper around the leading edge for a form and sand the cover to shape.

14.21 Find the cardstock and wrap the cup from the bottom of the lip and snug around ES-1. Tape or glue and remove the cardstock tube from the assembly.

14.18 Mark lines ¾” from the tail boom corners on the sides, top, and bottom to aid in sanding. Using various grits of sand-paper round the tail boom and lower fuselage corners to a rounded shape. The tail boom end under the vertical fin should be sanded down to match the profile of the vertical fin.

14.20 Find the plastic cup and the 1/4” balsa ES-1 . Then glue ES-1 to the bottom of the cup.

14.22 Insert the plastic cup with ES-1 from the backside of F-3.

14.0 TAIL BOOM, EXHAUST ASSEMBLY



14.23 Glue the exhaust support from the inside and let dry. Use tape to keep this assembly square.

14.25 OPTION: If you want to build a lower chin block hatch to gain access to your batteries you will need to remove the wood between the lower cooling slots in the 1/4” ply bot-tom. The pieces for the basic hatch are supplied as well as the magnets to attach to the bottom.

14.27 Cut ¼” balsa triangle stock to fit along the sides, CB-3, along the lower inside surface. Glue the chin block lower sur-face.

14.24 Paint the Cardstock Tube flat black, when dry slip the tube onto ES-1 to check fit. After final paint and finish of heli-copter glue in place.

14.26 Build the lower chin block by starting with punching out the chin block front (CB-1), rear (CB-2) and side (CB-3) pieces. Glue together to form the box structure. Make sure that the single notch in CB-1 and the two notches in CB-2 are down.

14.28 Cross sheet the lower surface with 3/32” balsa. Cut out the sheeting in the center notch of CB-4 to allow the Wire Strike Protection System (WSPS) to extend through.

14.0 CHIN BLOCK ASSEMBLY



14.29 Round off the edges and sand smooth. The Magnets go in CB-4 and the 1/4” ply bottom. This info is supplied to assist in building a hatch if needed. This is optional as removing the canopy is just as easy to inspect the batteries.

14.30 Sand the edges smooth.

14.0 HATCH COVER ASSEMBLY

14.31 Punch out and glue the two ¼” balsa AC lights together. Sand to the desired finished shape. The light goes on top of the doghouse behind the main mast.

14.32 Fuel proof the inside of the fuselage, transmission, tail gearbox cover, and canopy assemblies. We like to use 1 hour Epoxy thinned 50% with denatured alcohol then brush on and let dry. 2 coats may be necessary to completely fuel proof the inside.



15.1 Punch out the two 1/8” ply vertical fin leading edges, TSF, and glue to the 1/16” balsa vertical fin side leading sheet-ing, VFS-L, in the position shown on the plans. Only glue the back edges for now and the sheeting will be formed to shape later.

15.3 Using a flat sanding surface sand the back and front edges parallel.

15.5 Using the plans as a guide, glue the 1/8” ply vertical fin mounts, VF-M, to the inside edge of balsa sheeting. Temporar-ily place the assembly on the aircraft for a guide to sand the leading edge to match the lower part of the fin. Sand the lead-ing edge to the desired shape.

15.2 Punch out the upper leading edge former, VF-1, from 1/8” plywood and glue on the upper edge of the sheeting. Ap-ply glue to the remaining edge of the lower formers and glue the sheeting along the profile.

15.4 Cut a piece of ¾” balsa triangle stock and glue to the leading edge of the assembly so that the triangle stock over-hangs the sides equally.

15.6 Punch out the ¼” balsa vertical fin top, VFT, and glue centered on the top of the leading edge assembly.

15.0 TAIL COVER ASSEMBLY



15.7 Punch out the two 1/16” balsa vertical fin trailing edge sheeting, VFS-T, and the trailing edge formers VF-2 and VF-3 from 1/4th Balsa. Referring to the plans glue the formers paral-lel with the bottom edge and flush with the leading edge on one side of the sheeting. Sand the trailing edge to match the profile of the formers so that the other sheeting will sit flush. The op-posite sheeting will overlap the trailing edge and provide good surface area for glue adhesion.

15.9 Using a flat surface sand the mating edge of the trailing edge fin flush for proper fit.

15.11 The Landing skids are made up of 4 legs, 4 supports and 2 skids.

15.8 Glue the opposite sheeting over the formers. The trailing edge of the sheeting will overlap the trailing edge of the previ-ous sheeting. Sand the overlapping sheeting to match. Punch out the 1/4th Balsa top trailing edge former, VF-4, and glue into place flush with the top edge.

15.10 Assemble the two vertical fin covers and check for proper fit. Sand the top balsa block flush with the sides and to a rounded shape. Trial fit over your tail rotor and cut away the necessary sheeting for proper clearance.

15.12 Epoxy the 4 small aluminum support tubes into the 2 Skids. (JB WELD works best)

15.0 TAIL COVER, LANDING GEAR ASSEMBLY



16.1 Once dry do a trial fit into the fuselage with the 4 legs, Once satisfied with the alignment and fit (TAKE YOUR TIME WITH THIS STEP!!) NOTE: There is a left and right skid! Looking from the top you will notice the holes are drilled to the side. When assembling the landing gear the front of the skid should an-gle slightly to the inside.

16.3 You should have something like this.

16.5 Mechanic installation is not covered because there are so many choices. The bottom plate is Plywood so it would be a simple process of setting your mechanics into the fuselage. Block it up to the proper height using hardwood, rails (Supplied in the kit) then glue in place and frame with scrap Triangle stock. Drill 4 holes to match the mounting holes in your me-chanics and screw in place with the supplied 4-40 screws and blind nuts.

16.2 Once you’re happy with the fit mark the location of the leg were it enters the fuselage with a marker. Remove every-thing from the model and epoxy the legs to the skid supports and the end were it enters into the fuselage then reinsert. Use tape to hold in position until dry. Make sure to roughen up the aluminum were you are applying the Epoxy for best results. (DO NOT USE CA GLUE!!! YOU WILL NOT HAVE ENOUGH TIME TO POSITION EVERYTHING )

16.4 NOTES: If you feel more comfortable you may skip the Scale landing gear setup and opt for your stock landing gear from your pod and boom until you feel good about flying this Scale Model.

16.6 Thank you for purchasing one of our fine balsa scale Approach Engineering helicopter kits. We are always upgrading our helicopters to make them easier and more enjoyable to build. If you have an improvement or Question please email us at : [email protected] Thank you. Brenda Dawson (Dr.Tim’s Patient Wife)

16.0 INSTALLING THE MECHANICS