It’s go time.

7 hours.

313TD is now ready to fly.   It is legal, insured, fueled and ready.  If I didn’t have a mountain of work to do at work, I could go up there, push the airplane out into the open, fire it up, and take off.

It’s not finished.  Don’t get confused on that: Wheel pants and gear leg fairings still have to be done, and I’m still working out the engineering particulars on that one, because I have to suspend the aircraft in such a way that the weight is off the wheels to align the fairings.   Otherwise they act like little rudders, pointing the plane in an off-track direction.   This means you have to fight it with rudder input, and that means you lose efficiency because your airplane is essentially trying to fly sideways.

Efficiency is important.   Yesterday, I bought 22 gallons of aviation gasoline at $6.06 a gallon.  Ouch.   The reason for buying this gasoline is in preparation for the first flight, and also to calibrate the fuel level sensors in the wing tanks.   Each tank holds 21 gallons for a total of 42, so the plan was to do one tank at a time.

Our local Oxnard EAA chapter, which consists of the 8 guys who can reliably show up on the last saturday of every month and take care of business, has access to the really cool hand cranked fuel cart, which pumps both forwards and backwards and measures the amount of fuel pumped in either direction.

I called the Jet Center and had them put 22 gallons in the cart,  Which I could then use to increase the level in each tank according to the calibration “marks” on the EFIS.  If I recall correctly, these are 0.1, 4.6, 8.3, 12.5, 16.7, and 21.0 gallons.    The sensor is attached to a float inside the tank connected to a rheostat, and the numbers it puts out are simple resistance values read by the EFIS.   So with each amount pumped in, the settings menu gets the resistance value entered at that amount.   Simple.   I’m not sure how dead-on-balls accurate it is, but my initial test with the pump put 5 gallons into a 5 gallon gas can, so that was probably good enough.   I’m also not sure how much fuel it took to prime the pump and fill the filter chamber, but I’d put it at roughly half a gallon.   That’s OK, I drained about 2 and a half gallons from the aircraft tanks into a 5 gallon can before I started.

Also, this process needs to be done with the airplane in level attitude, because that’s when your fuel level actually matters.  Once again, Ron’s old lift was the solution for lifting the tailwheel.   The process was to pump 21 gallons into one of the tanks, set the levels, then pump it back into the fuel cart to verify the settings.    This also involved draining the current tank after the pump had sucked all the fuel out of the section where the fuel cap is, because even after pumping out all the fuel, there’s still 4 gallons left in the tank.   Also, when the pump runs dry, it still moves the counter.   Did I mention this thing is hand cranked? Yeah.  I’m sore.  Anyway, I repeated this process twice on each tank and the numbers were within .2 gallons each time, so the pump and the sensors appear to be doing the right thing.

So that’s done.   I’m ready to scramble.   All I need now is a day with good weather and relatively little outside stress, and we’re going up.

Comments (0)

› No comments yet.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.