BALDWIN CITY, Kansas — McFarlane Aviation Products has won FAA-PMA approval on new complete fuel selector valve assemblies for Cessna 170, 172, 175, and 177 aircraft.
Company officials add they expect approvals soon covering more airframes.
For years, McFarlane has been repairing Cessna fuel selector valves. Ben Strahm and Andy Pritchard, both A&P technicians at McFarlane, found corrosion to be the number one issue that prevents fuel selector valves from being repaired.
Because of this, McFarlane hard anodizes the complete valve body outside and inside, company officials note. All attach fittings are also anodized.
Careful consideration of metal used for the components was also noted, company officials add. In the original Cessna valves, dissimilar metal corrosion is a problem with the lower bearing. McFarlane’s design incorporates an aluminum bushing that is hard anodized.
Since repairing valves is an option that the customers still want available, each component of McFarlane’s fuel selector valves hold their own approval and are directly interchangeable within the original Cessna valves. This means that original valves may still be repaired by using McFarlane’s components at significantly less cost, according to company officials.
AD#99-27-02 is applicable to some of the cams in the original Cessna valve 0513120 series. Because of this, McFarlane began its fuel valve project by developing the replacement cam.
The AD was not the only reason for starting with the cam, Strahm said.
“So many of the valves that we have repaired we had to replace the cams because the index on the shaft had been damaged,” he explained. “The cams appear to be damaged during reassembly or while reattaching the control linkage. There is a very specific way in which these must be assembled in order to avoid damaging the index while installing the roll pin.”