New parts are pulled from our inventory and assigned to the propeller's work order.  Sub assemblies are built up.  The propeller is then assembled.  Angles are set and the propeller is actuated. If the propeller requires deice boots they are installed now.  The last thing to be done is static balance using our precision Universal balancer and final inspection.

 Some parts require mandatory replacement at overhaul or due to Service Bulletins or A/Ds.  Parts are visually inspected for damage, corrosion, and defects. Depending on the part, some damage and corrosion can be worked out. Parts are then dimensionally inspected.  
Blade width, thickness, angles, and face alignment are checked at various blade stations. If the face alignment (the fore and aft bend) or angles (twist) of the blade are out of manufacturer's requirements, it is corrected at this time.  This is a time consuming job, but when done correctly, will aide in making a smoother flying propeller.  Once the parts have passed the visual inspections, they move on to NDT or Non Destructive Testing. The following methods are used for finding cracks and other defects.  We use three forms of NDT- Eddy Current, Dye Penetrate, and Magnetic Particle. 

​​Disassembly                                                                                              During disassmbly the propeller if functionally tested and blade angle settings are checked. The mechanic will note any malfunction or damage.

Initial Inspection
 Both fixed pitch and constant speed propellers follow these procedures. When the propeller arrives it is assigned a work order, inspection form and a cart that will travel with it throughout the overhaul process. Propeller model number and aircraft application is researched for Service Bulletins and Airworthiness Directives pertaining to it. 

Warner Propeller & Governor Co. 

Proudly serving the aviation community since 1965

 If a part requires a modification or rework, it is sent to our machine shop.  After rework or modifications the parts go back to the inspections department before going on to re-finishing.

 Our environmentally friendly parts washer removes the majority of grease and oil.  Media blasting removes paint and other adhesives.

   Anodizing and stripping line   Cadmium plating/stripping line   Blade being reworked    

Prop in parts washer             Blade being media blasted       Hub being media blasted

Propeller Overhaul 

Blades, hub, and some internal parts are anodized or cadmium plated for corrosion protection. After cadmium plating, parts are baked in an oven for 8 hrs. at 350 degrees to prevent hydrogen embritalment.  After chemical treatment, some parts are then painted for further protection

 All coatings are removed prior to inspection. The anodized or alodined aluminum parts and the cadmium plated steel parts are chemically stripped. The blade's airfoil is reworked to remove nicks and dings received during operation.  This process also stress relieves the blade.

Universal Balancer for a precision electronic static balance

Deice boot being moved        Propeller being disassembled   Propeller on cart for travel

Work order initiated                Angles being checked            Track being checked

Lathe                                     Mill                                       Surface Grinder

Assembly of Hamilton Std.        Assembly of threaded McCauley

Blades after anodizing           Oven for cadmium plated parts       Blades being painted

New Parts Inventory                   Propeller ready for assembly

Sub assembly build-up                Assembly of clamped Hartzell


Eddy Current                         Dye Penetrant                        Magnetic Particle 

PHONE: 520.294.5671