1. FLY THE AIRCRAFT

To establish baselines for flying in different configurations in accordance with GlaStar Assembly Manual (see excerpt below), first establish full forward CG at minimal weight, and record the stall speed and top speed (Hiatt & O'Neill, 1997). Separately, establish full aft CG at gross weight, and again record the stall speed and top speed. Also record stall speeds at various flap settings and power settings to be determined.

____________________

start of video

2:55
2. APPLY TUFTS TO THE WING

1. Apply tape along chord of wing at fuselage and wingtip, which will provide a surface for making notes and marks.

2:25
Note: Some people choose to skip tufting and apply test VG in 15% range of leading edge of wing, then test fly to find optimal placement of VGs. The first 15% from leading edge toward the trailing edge is most effective.

VGs are always installed in the area forward of the stalled section of a wing.

2:50
2. Run masking tape along the wing just above the wing’s leading edge, then along the trailing edge.

3:09
3. Starting at the inboard section of the leading edge, run masking tape to the wingtip, then mark 3-inch intervals on the tape to the wingtip.

3:30
4. Repeat by adding masking tape along the trailing edge, then mark 3-inch intervals on the chord of the wing at the wingtip and at the fuselage.

4:45
5. Count the number of marks along the leading edge of the wing. The total number of marks equals the total number of wool tufts to be attached.

4:58
6. Prepare a 1-in x 2-in board x a length somewhat greater than the wing’s chord, then attach a nail to each end a few inches greater than the length of the chord.

5:30
7. Tie a knot in the yarn, then wrap the yarn around the nails half plus one as many times as there are marks on the tape.

5:50
8. Prepare to attach tufts to the wing with short individual pieces of tape at the leading edge of the wing.

6:11
9. Attach one length of yarn to the front of the leading edge inboard at the fuselage, draping it over the trailing edge of the wing.

6:29
10. Apply tape span-wise across the wing at three-inch intervals, so tape aligns with the same three-inch mark at the fuselage and corresponding mark at the wingtip. Also apply tape across the trailing edge of the wing (what will become the lowest row) over the yarn.

6:50
11. Press the masking tape lying across each section of yarn around each side of it to secure it to the wing.

7:09
12. Cut loose all yarn-tufts at the trailing-edge end of each section.

7:37
13. NB: Conspicuously number the first 6 rows, and ensure they are visible to the cameras.

7:28
3. FLY THE AIRCRAFT — OBSERVE TUFTS — ANALYZE RESULTS

14. VGs will be installed forward of the stalled area.

8:15
15. While flying in full forward CG at minimal weight, and separately, full aft CG at gross weight (in accordance with GlaStar Assembly Manual), record the stall speed and top speed, to determine where to place the VGs and for comparison after installation.

8:23
16. Discussion and analysis of movement of the tufts in straight-and-level and stalled flight conditions.

8:32
17. Discussion of the end of the stalled area, at the second row of tufts.
- The first row of tufts are still straight.
- The second row of tufts are in disarray at the inboard section of the wing.

8:43
VGs move forward in the stalled area.

8:56
18. 4. PREPARE VGS FOR TEMPORARY INSTALLATION

9:02
19. Cut 36 inches of double-sided tape and secure with tape at each end.

9:10
20. Place each VG tightly against the side of the preceding VG on the tape. Make it tight for ease of separating the VGs from the tape. Apply the VGs in a line for ease of trimming in the next step.

9:28
21. Cut off excess tape from the front and back of the VGs. Remove using an X-Acto knife on a cutting board.

9:54
22. Flip the VGs over, then use the X-Acto knife to make a V-shape between two adjacent VGs, then cut apart along the V.

10:23
23. Temporary placement of the VGs: Wipe the affected wing area with isopropyl. Remove dust and wax for maximum adhesion.

10:32
24. Starting from the inboard section of the leading edge of the wing, add a 16-inch strip of tape down the fuselage, and another 16-inch piece of tape at the wingtip from the leading edge along the chord toward the trailing edge.

Note: Aircraft changes from blue RV with tufts to Tom Ellsberg’s RV with no tufts.

10:47
25. From notes recorded when wing was tufted, add marks where wing was still flying (Row 1? Not visible in video.)

11:23
26. Attach a black thread tautly between the two marks on the tape from previous step.

11:40
27. Stretch a piece of masking tape span-wise on the leading-edge side of the thread.

11:58
28. To determine placement of the VGs, stretch a measuring tape across the masking tape then mark the tape.

11:59
29. Spacing of the VGs: Generally, start the first pair of VGs eight to ten inches away from the fuselage, and space VGs at eight to ten-inch intervals till reaching the flap-aileron junction, then reduce spacing to six to eight inch intervals for the remainder to the wingtip.

Question: Why so far apart? I see other aircraft with much closer spacing of pairs, perhaps four to six inches.

12:23
With yellow RV in video, because it is an aerobatic aircraft, spacing was started at six-inch intervals at the fuselage, with four groups at eight-inch intervals, and the balance of Gs at six-inch intervals.

12:30
30. Align the notch in the interval tool with the mark on the tape.

12:39
31. To align VGs properly into the airstream: Remove the adhesive backing on the tape on the VG. With the leading edge of the VG pointing to the wing, slide the VG under the edge of the layout tool and press firmly into place. Repeat on the other side of the layout too.

13:00
32. Brief discussion about placing VGs on elevator and rudder

13:15
5. FLY THE AIRCRAFT — DOCUMENT AIRSPEED & HANDLING — ANALYZE RESULTS

33. Fly the aircraft and document airspeeds and handling characteristics. Moving the line of VGs forward may further reduce stall speed, but may also increase drag and lower top-end speed a few knots.

13:27
34. Feel free to adjust spacing between the VGs, closer or further apart.

13:35
The tape may remain tacky enough to be moved once. Recommend replacing tape after one move.

13:46
Soaking the VGs in acetone a short while will loosen the adhesive.

13:52 Discussion of inboard/outboard wing design: Flap-aileron junction commonly defines the boundary between inboard and outboard of wing (14:00), for stall recover by use of ailerons. Therefore, avoid heavy concentrations of VGs on the inboard section of the wing.

14:15
6. PREPARE VGS FOR PAINTING AFTER LOCATION HAS BEEN SET

34. Prepare VGs for painting after location of VGs has been set.

Missing note: Build a paint stand for VGs in a simple T-section of 1/2-in x 1 in x 6 ft. VGs lie in a single row of masking tape, which is attached by pushpins to the 1/2-in wide surface of the wood. See 14:52 for photo.

14:22
35. To ease cleanup, take extra time to avoid excess paint on VGs.

14:36
36. Fold masking tape over itself three times, and stretch the tape over the board. After folding the tape again three times at the opposite end, attach to the board with a pushpin.

14:57
37. Remove adhesive from VG backs with acetone, then space about 1/8-in apart from each other. Press firmly in place.

15:25
38. Paint starting at back of VGs at a 45-degree angle, then in one continuous motion spray the back side of the VGs. Apply a very light coat.

15:49
39. Repeat on the leading edge of the VGs, at a 45-degree angle. Apply a very light coat.

16:07
40. By end of painting one then the other side, the first side should be ready for a second or even third coat.

16.11
41. Make sure there is no excess paint in the footprint area of the VGs. Minimize paint running off onto the tape, to avoid having to remove it prior to installing the VG (16:20). Remove VGs from tape when dry.

16:34
42. Weeding the masking template
Unroll the templates on a table. Using masking tape, secure the underside corners to the surface. Pull up corner and peel back gently, then remove center pieces as well.

17:20
43. Remove the rectangular center pieces (where VGs will be placed). Lift and remove pieces.

17:58
44. Placement of templates on wing
As in placement of VGs for temporary installation, apply 16 inches of masking tape on inboard section starting from leading edge of wing along the fuselage, and another 16 inches at wingtip starting from the leading edge toward the trailing edge.

18:11
45. Mark the tape based on notes made in the final flight test.

18:16
46. Move the marks at the fuselage and wingtip one and 1/8 inch forward to accommodate the width of the template, then run a thread span-wise between the two marks.

18:30
47. Run a strip of masking tape along the leading-edge side of the thread.

18:46
48. To find the final location of the VGs, place marks on masking tape using a tape measure and the notes taken from the flight test.

19:01
49. Place the templates on the wing, carefully removing the backing, and aligning the notch on the template with the thread.

50. When the templates are attached, remove all tape and thread.

19:35
51. Overview of attached templates (18 pairs/36 VGs on yellow RV).

Question: Why not replicate spacing that appears on the RV? (36 pieces)

19:46
52. Gluing VGs in place
Attach paper towels to the leading- and trailing-edge sides of the templates. To assist in easy cleanup after using fine-mist spray activator, apply masking tape to paper towels and templates, and seal gaps between templates.

20:06
53. Using Scotchbrite pad, gently sand in cut-out areas of the template. Do not sand down to bare metal; just sand enough to scratch up the surface of the existing paint.

20:39
54. Remove residue of sanding with isopropyl, turning cloth frequently.

21:26
55. Cut cotton swabs at a 45-degree angle, to use for cleaning up excess glue.

20:52
56. Review Locktite 330 instructions. Apply spray activator one wing at a time, with a light spray to each of the cutout area on the templates. Ensure each exposed area is covered with activator.

21:40
57. Apply a small amount of adhesive to bottom of VG, then align VG in cutout area of template. Adhesive will ooze out. Glue starts to set in 60 seconds, so ensure proper placement of VG before glue starts to set before cleaning, for ease of removal.

Adhesive is clear out of the tube, but turns amber when cured. Therefore, remove as much as possible before it sets up.

22:40
59. Remove paper towels used to mask templates. Remove masking tape around templates, then remove templates from front to rear.

23:55
60. Remove any overspray with isopropyl.