Feb11

5 Feb 11

I decided the Speedy Cuffs worked so well I'm going to make similar fairings for the upper gear leg/fuselage intersection. The problem with working under the airplane is lying on your back working upward. Nothing wants to stay in place. Gravity pulls everything down.

	I used Great Stuff foam but it does not stay in place when you squirt it on the bottom of a plane. So, I had to spray some on - half would drip/drop off - I'd spray on more until I got enough to start shaping To right is foam fairly well shaped, but with lots of holes due to bubbles formed in the foam.
	To fill the holes and make a smoother surface, I smeared on Bondo and sanded it to shape and added tape over the final form.

The resin load fiberglass was clumsy to work with under the plane. It was heavy with resin and wanted to fall off the bottom. I got it to stick only to discover the next morning that the inboard half of one side had fallen down. It had to be cut away and relaid.	Here are the fairings before trimming	After initial trimming and fitting.

20 Feb 2011

First flight today in a while and did some flight testing on things I've been needing to do.

Bhrent Waddell helped me with some work on the airplane and then we test flew it to check various things.

I made a mess of the upper gear leg Speedy cuffs so we had to cut off part of the old glass and add new - which turned out good. Then we flew three flights to test the following:

1. Max RPM after adjusting governor

2. Tuft and video nose pant to check airflow

3. Tuft and fly winglet to check airflow

4. Check deflection of elevator horn at various speeds with and without the tail weight.

The airplane hit a brick wall at about 186 KIAS and would not go on up to 190+. I'm not sure what the problem was. Will do another max speed run tomorrow.

The max RPM would only go to 2670, so the recent governor adjustment made little or no difference. I think we'll leave it where it is and torque and safety wire it. We tufted the nose pant and each wingtip and taped on the left winglet to do more testing. We mounted a video cam under the left wing to record the nose dam tufts and took still pics of the wingtips. The video revealed an area of turbulence on the nose dam, so I'll add some foam and glass to improve the air flow. The wingtip tufts indicated significant turbulence on the top of the normal wingtip whereas the winglet side had smoother airflow. We'll check performance with both winglets. The elevator horn protrudes about 1/2-3/4" above the horz stab depending on speed. Addition or removal of the tail weight makes no difference.

Tomorrow's test flight will include:

1. Removal of aileron tab and addition of step fairing

2. Max speed run

3. Test both winglets

4. Test elevator horn fairings

23 Feb 11

We got in several flights over the past few days and did lots of testing. Removal of the aileron tab and addition of the step fairing did not help. My theory was that the step was creating lift on the left side of the airplane causing it to roll right. So by reversing the lift created by the step I should be able to eliminate the rolling tendency. Well, it made no difference, so the step was not the problem. With the left aileron tab removed the airplane rolls right. And, as it turns out, fore-aft placement of the aileron tab is important. When I reinstalled the tab, I got it too far forward and we still had a right roll. After adjusting it's position aft, the rolling stopped and it flew hands off at all speeds. So, looks like I'll have to make a permanent, fiberglass aileron wedge.

The max speed run was not impressive, but it was likely due to the tufts and other drag on the airplane. We tufted the nose pant and top of wingtips and mounted the video under the wing to film the nose pant. The wingtip tufting revealed much of the same info as last time - that is, the aft half of the wingtip has disturbed airflow on the upper surface. When a winglet is added, the airflow smoothes out. I'm not yet convinced the winglets improve airflow or reduce drag enough to make them worthwhile.

The nose pant video revealed some turbulence (with some reverse airflow) on the aft portion of the Speedy air dam. So I will add some fiberglass to the dam to improve airflow and tuft test it again.

The remainder of flights were to get Bhrent FCP qualed and comfortable.

Video of Speedy Nose Pant Air Dam

As the video shows, there is a turbulent area 2/3 back on the air dam. I believe the problem is a too rapid transition from the side of the dam to the tail fin. So, I decided to add fiberglass to make the transition more gradual.

To see the video of tufting after the mod shown below was completed, see the link at the bottom of the page.

	Started with globs of foam and then shaped it close before adding Bondo. Sanded the Bondo and taped over.
	Left is after the Bondo and foam were removed and it shows the rapid changed from the sides to the aft fin. At right the added glass makes a smoother transition. This photo is before any trimming or sanding.

Nose pant Video after above mod

The airflow transition aft of the tire is much smoother than before.

Next update in Mar