Adhere to the manufacturer’s specifications for trouble-free service
For decades, GSC propellers have been used on tractor and pusher aircraft, gyrocopters, airboats, powered parachutes, and powered paragliders. They provide excellent thrust and performance, and when installed correctly will continue to prove themselves as the best propellers on the market today. As with any specialized equipment, installation as well as care and use, must closely adhere to the manufacturer’s specifications. This will result in many hours of trouble-free service.

Issued Service Bulletins:
Pitch Setting:
GSC Service Bulletin - May 17, 1999
Pitch Setting
Assembly Instructions:
Aluminium Roots End Assembly
Standard Black Root Ends
Questions and answers:
Do I need to balance my propeller?
Should there be a gap between my hub halves?
What is the easiest way to install my prop?
I can no longer see a gap between my hub halves. Should I be concerned?
How do I use the GSC Pitch Adjusting Tool?
I have a propeller which is quite old. Can I replace just one blade?
What is the ideal torque on all the bolts?
I seem to be getting a vibration from my prop, what do I do?
Should I check the tracking on my GSC Prop?
What do those numbers mean, which are stamped on my blades?
Do I need to balance my propeller?

If you have a brand new propeller, there is no balancing necessary. All propellers are final balanced at the factory. If, however, you have altered your prop in any way, then balancing may be necessary. Propellers must be balanced using a proper balancing method, not simply by weight.
What's the easiest way to install my prop?

The multi-blade propeller is easily assembled on a flat working area (following assembly instructions). All bolts are finger-tight only at this time. The propeller can then be mounted on the prop flange on the aircraft, and pitch can be set while on the aircraft using the GSC Pitch Adjusting Tool.
How do I use the GSC Pitch Adjusting Tool?

Complete assembly and use instructions are provided with each tool. The downloadable Pitch Setting diagrams and instructions on this page will help you in setting pitch using GSC Pitch Adjusting Tool.
What is the recommended torque on all the bolts?

All bolts, when using the GSC blades with black composite root ends, are to be torqued no more than 100 in/lbs. or 8.5 ft/lbs. Blades with aluminum root ends can be torqued more.

Should I check the tracking on my GSC Prop?

Yes, you should check the tracking of all blades while they are installed on the aircraft. The tolerance of the blade tracking is 1/8" at the tip. Blade tracking can be manipulated slightly by applying forward or aft pressure on the appropriate blade while torquing bolts.

Should there be a gap between my hub halves?

Yes, the propeller hubs are designed to have a 30 thousandths gap when the round root end of the blades are placed inside. Do not over-torque bolts until the gap disappears. Torque to a maximum of 100 in/lbs. ONLY!

I can no longer see a gap between my hub halves. Should I be concerned?

There should always be a slight gap. This design is to give a clamping action to the blades and not allow them to change pitch in flight. Our experience has shown that a lack of gap is usually the result of over-torquing.

I have a multi-blade propeller which is quite old. Can I replace just one blade?

Yes, we can replace just the one blade. However, if the propeller is more than two years old, the new blade may not balance with the old blades and it will be necessary to return the old blades and have us balance the new blade to them.
I seem to be getting a vibration from my prop, what do I do?

Double-check your tracking (tolerance of 1/8" at tip). Double-check the pitch of your prop (variance from blade-to-blade should not be more than ½ degree). If propeller has been altered in any way, balancing may be necessary. If vibration still persists, it could be from another source, such as engine crankcase or gearbox issue.  Simply call GSC Systems for advice.

What do those numbers mean, which are stamped on my blades?

The numbers are reference balance numbers which GSC uses in their balancing method. They should be quoted when ordering replacement blades. It is important that in a set of blades for a particular prop, these numbers all be the same.