By Maj. Allen L. Gilbert
Aviation Safety Officer

A Naval Air Depot Cherry Point employee recently won the first award in a new program here that recognizes personnel who provide safety excellence for fleet and depot personnel.

Jerry Harper of Fuel Controls and Accessories captured the Naval Air Depot Cherry Point Aviation Safety Professional of the Month Award for February on Feb. 26. The program was restarted last month as a way for the commanding officer to recognize any depot employee who makes significant contributions in aviation safety for depot and fleet activities.

While working on P-3 APU centrifugal switches inducted from fleet units, Harper discovered a trend of incomplete switches inducted from the fleet. About 25 percent of the P-3 APU centrifugal switches inducted had different parts from different units assembled together to make a complete unit. Original manufactured switches are a two-part assembly that requires calibration of the two parts together for the switch to function correctly. Harper discovered and researched the discrepancies in switches turned in by P-3 fleet maintenance activities.

Installing the component on the aircraft requires that the two halves be separated allowing access to the mounting screws on the barrel section of the switch. Once the barrel assembly is installed on the APU, the switch is reinstalled. This process does not upset the calibration between the two units. A number of the failed switches were being sent to Cherry Point without the barrel assemblies, indicating that the fleet units are only replacing the top switch section of the assembly and possibly discarding the new barrel assembly. Harper discovered that the barrel assemblies received showed a marked increase in the amount of wear on their internal parts, possibly indicating longer use, most likely because they were not being removed with the switch when it failed. Harper and fellow artisans collected evidence that led engineers to believe that fleet maintenance personnel were mismatching switches even though the fleet manuals give clear instructions not to mismatch the parts. The ramifications of mismatching these components are:

• APU over-speed with catastrophic failure and possible damage to platform and crew;
• Exceeding duty cycle of starter;
• Not obtaining a 95 percent level to allow load to be placed on the APU;
• NADEP Cherry Point’s total cost of
repair is $1,930 per switch before ordering missing barrel assembly which costs $960;
• P-3 starter failures appear to be on the increase according to the shop (this may be related to item 2).

Harper’s research into the mismatched parts led to an engineering advisory report and subsequent awareness on the problems currently observed in the fleet P-3 APU centrifugal switch malfunctions. His effort and attention to detail greatly enhanced fleet awareness of a major discrepancy.

Harper’s initiative will save $960 per switch replaced for the depot. His work on the issues also prevented possible aircraft damage and personal injury to the personnel working on the P-3 Orion. This was not only an issue of safety, but also an issue of money savings for the depot.

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Cutline: Jerry Harper works on a switch assembly similar to one that he discovered safety issues on, winning him the depot’s Aviation Safety Professional of the Month Award for February. (Photo by Mike Barton)