This "Tips and How To's" Series on Model Turbine Fuel Systems may help you avoid some of the common, and not so common, items that can cause a "Flame-Out".

  A proper fuel system installation, periodic maintenance checks, and certain precautions when handling and storing your turbine powered model are necessary for reliable engine operation.

Clunks must stay in the fuel

  For jet models that have a large unbaffled tank as the primary fuel storage area, sometimes the clunk can get stuck in the front of the tank because of transporting or storing the model nose down.  Possibly, a landing that ends up with the model flipping over can also force the clunk forward. The flexibility of the tubing that serves to position the clunk in the tank can also contribute to the clunk getting stuck in the front of the tank. To check that the clunk is not lodged forward, hold the nose of the model up and shake it sideways such that you can hear the clunk tapping the AFT side wells of the tank.  If it is not obviously functioning properly, remove the tank and check it out.

Festo Fittings
precautions

  Use them on the positive pressure side of the pump only and avoid sharp bends in the tubing close to the fitting. On the positive pressure side, you can spot a small leak, on the suction side, if there is less than a perfect seal, air will get into the fuel system.

In-Line Fuel Filter

  Most fuel filters utilize a fine mesh screen and an "O" Ring seal. This allows occasional disassembly and cleaning.  The Fuel Filter should be placed downstream of the Fuel Pump and ALWAYS oriented vertical to the model's longitudinal axis. The vertical orientation will allow an initial run-up bubble to dislodge before your first aerobatic maneuver.

The Ultimate Air Trap - U.A.T.

  A properly designed and manufactured U.A.T. is a vital part of any turbine fuel system.  The container should be translucent so that you can visibly determine how much air vs. fuel is present, before and after a flight. A container that is a bit flexible will also reveal supply and demand pressures during the fueling process and engine fuel pump demands during high power settings.
  Of course, the BVM U.A.T. has all of these features and a unique porous sack inside that can deliver bubble free fuel even if the 4oz. container has trapped so much air that it occupies more space than fuel.
  BVM has supplied U.A.T.'s to the turbine industry since 1997.  BVM offers the U.A.T. in its original format that is ideal for engines up to 140 Newton's of thrust, and a Hi-Flow version for the larger engines. See www.BVMJets.com/HiFlow

Stay tuned for more fuel system Tips and How To's.