Hobbs Hours

Notes and Data

14 to 18 hrs

First Break for Maintenance
I took a break from flying to catch up on a few things. I have about 16 hours on the airplane now. (21May2011)

1. Baffle mod - In an attempt to cool cylinders 5 and 6 a little more, I added baffle material to where the motor mounts protrude through the rear wall of the air dam.
2. Fuel Flow Sensor - Brand new FlowScan FT-201B fuel flow sensor died after 9 hours of operation. I ordered a new one from GRT and they now ship the "red cube" FT-60 which is made by Electronics International. It is identical to the original one except that the mounting holes don't line up and the input port is 0.5" higher. So if you don't mind laying on your belly for 6 hours to work in a 8 inch wide tunnel to fabricate new fuel lines, rivet in new nut plates for mounting and splicing wires, then you won't mind the difference. The new sensor is shown installed in the photo below.
3. Spider Seep - I put foil around the fuel lines to track down the seepage. The photo below shows the blue fuel stain behind the B nut of the fitting of the main feed hose. This hose was delivered with the engine. I replaced the hose and it seems to have solved the problem. But if it hasn't, I discovered DEL crush washers made for flared fittings that I can fall back on.
4. Hydraulic Fluid Seep - This seep was isolated to the pilot side, right pedal, pressure side fitting. I gave the fitting another slight turn and it seems to have stopped the leak. The pipe fitting is already very tight and if this doesn't solve it I would have to remove the fitting which means draining the brake system.
5. EFIS Serial Ports - My PFD computer sees the #1 AHRS but doesn't seem to see the #2 AHRS. The MFD sees both. There may be a mistake in my PFD serial port harness and it looks like I get to do a panel dive to find out. I haven't worked on this yet.
6. I installed my wheel fairings and will continue aerodynamic testing with them in place.

20 to 26 hrs

Summer is Here!
Arizona temperatures will be up over 110 this week so all outdoor activity is pretty well limited to 5AM to 10AM. As of 21 July 2011, I have 28 hours on the airplane. Here are a few more things that I have done to the airplane.

Lower Cowl Heat Shield
Upon removing my lower cowl, there were brown discoloration heat marks on the side of the cowl (see photo below). This is not from the muffler but is from the exhaust pipes preceeding the muffler. I added Thermo Tec, Cool It, aluminized heat barrier, adhesive backed,13575 to the cowl. It conforms nicely to the shape of the cowl and the adhesive is rated to 300 deg F.

Brake Hydraulic Leak Part II
The fitting that is leaking is the 90 degree pipe fitting on the pressure side of the pilot side right brake master cylinder. This fitting has to point up so you are faced with making full turns on the fitting once snug. I tried clocking from the 11 O'clock to the 1 O'clock position and it stopped leaking for a week and then started again. So I had to remove the fitting and reseat with a generous amount of teflon. Changing the fitting was the easy part. The next 3 hours were spent trying to bleed the brake system as well as I had it before. This was a major PITA!.

26 hrs

Fuel Tank Vent Leak
This is the biggest problem I have had since starting to fly the airplane. It is complements of the quick build wing builders. I noticed that I was dripping fuel from the right wing fuel tank vent. The leak is coming directly out of the vent, not around it. The Vans vent system runs the vent pipe from the high side of the tank, through the fuel, to a bulkhead fitting at the lower end of the tank. This fitting is submerged in fuel whenever the tank has 22 gallons or more of fuel. Externally, there is just a pipe that you add to exit to the bottom of the wing and complete the vent system. I've concluded that the leak is at the flared tube to bulkhead fitting inside the tank. This fitting is not accessible once the tank is completely rivited together.

There is a 1.5" diameter hole for the fuel sender located about 3.7" away from the vent bulkhead fitting which is shown in the top left photo below. You can just barely touch the internal nut with your middle finger from this hole. My first step in developing a tool to go in the hole and turn the nut was to make a mock up of the fuel sender hole and vent position. The mock up is in the top right photo below. Then with expert help from work, we developed a tool that could go in the hole and swing far enough past the hole in each direction to turn the nut. You have to be able to swing the wrench far enough so that it can be repositioned enough to pick up another flat of the nut.

I flew off the right fuel tank as far as I could in flight. Then on the ground I transferred the remaining fuel from the right to left tank. I was able to go in and tighten the nut at least one and a half flats of the nut. It seemed pretty tight to me so I reinstalled the fuel float sensor, buttoned everything up and filled the tank with fuel. I wish the story ended here but the fitting continued to leak.

I decided to give it another try, so I flew off the fuel, removed all the cover panels and the fuel float sensor and tightened the fitting as much as I could using the tool. It seems really tight to me now and I don't think going any tighter could possibly be productive. Well it looks like that did the trick. It has stopped leaking. yeah! If this doesn't hold up I plan on removing the tank, capping the existing vent, and installing a new always dry vent at the outboard end of the tank.