In the early 70's Al Blatter, a member of the Detroit Cloudbusters, designed the Blatter 40 to help introduce modelers to the world of rubber powered indoor duration model airplanes. The design is simple like many of the early ROG (rise off ground) models but has proven to be a very good flier. The Blatter 40 was designed during the era of the North Pacific Sleek Streak models that used a nice plastic prop and prop hanger/thrust bearing. Al incorporated that then readily available front end in his design. Over time the Blatter 40 has been built by countless numbers of people wanting to try indoor Free Flight. Recognizing the flying potential of the design, the Cloudbusters early on established a competition event for the Blatter 40. That encouraged even more models to be built and enjoyed by the builder. The only rule for the event is the model has to be built to the plan. Current day front ends can be used but no changes to the prop can be made. No scraping off plastic to make them lighter, for example. Weight can be added to a light prop blade to balance the prop and lubrication can be used on the prop shaft. Performance of the Blatter 40 can be 1 minute for people just becoming familiar with indoor duration flying, and close to 4 minutes for an experienced indoor flyer.
To make sure the plan package can be printed on all generally available printers it has been set up to print on a 8 1/2 by 14 inch sheet of paper (U.S. Legal Size). It is important to note that you should have any print scaling (print to fit printer margins for example) turned off when printing the content of the provided Adobe PDF file.