Fuel Line Modification 

from RotorWay

Mandatory Compliance Bulletin M19

This was a must do thing and had to be performed on our ship.

This was something Rotorway came up with for a fix to a couple of potential problem some of the helicopters were having. Seems some ships were running out of fuel at or around 5 gallons plus its said that there was an issue of CG from the right hand tank having more fuel in it than the left hand tank.

Theory is

that the fuel being dumped back into the passengers side tank was at such a high flow rate the fuel didn't have time to equalize and maintain equal amounts of fuel in each tank. This caused two problems, one being the right side of the ship was heavier causing a CG problem and the other was when the fuel level got so low somehow the fuel pumps would suck the left hand fuel tank dry allowing the ship to run out of fuel.

Seems to me that with the left hand tank line being smaller it would restrict the fuel flow
and the pumps would be able to draw fuel easier from the right hand tank. Personally, I think the whole thing was a result of the line to the left hand fuel tank being way too small in the first place.

RotorWay also went another step and required you
to reroute the fuel return line into the vent cross tubes that run from tank to tank at the top of the fuel tanks.

I hear it works pretty good unless you happen to forget to replace your fuel cap.

The fuel comes spurting out of the tank with major pressure spraying everything in sight plus dumping recirculated fuel overboard. We haven't had this happen to us yet but according to Homer Bell it happened to someone he knew so be super careful on that preflight checklist to check those fuel caps or you may be the next one to have this happen.

END