Fixed-Wing aircraft

• Airflow Systems Manufacturer of aircraft air conditioning and turbo intercooler products.
• Cessna Pilots Association A unique technical information service for Cessna owners.
• Cessna Aircraft Company The Cessna Aircraft company
• Hartzell Propeller Inc. Hartzell Propeller Incorporated
• McCauley Propeller Systems McCauley Propeller Systems
• Mooney Aircraft Company The Mooney Aircraft company
• Sensenich Propeller Company Sensenich Propeller Company

Rotary-wing aircraft

• American Helicopter Society  The Vertical Flight Society.
• Helicopter Association International The international association dedicated to helicopters.
• Helicopter History Site Site dedicated to helicopter history.

Homebuilt aircraft (all types)

• CH-7 Home Page HeliSport Helicopter home page.
• Experimental Aircraft Association The leader in Recreational Aviation.
• Homebuilt.org Lots of information for the homebuilder.
• Popular Rotorcraft Association The association for rotorcraft homebuilders

• Light Plane Maintenance Maintenance information for the aircraft owner.
• Pama.org Professional Aviation Maintenance Association homepage.