Customers of CHC (Cellulose Helicopter Company) have been complaining about limited flight time of CHC helicopters. A team of CHC engineers, pilots, managers and field representatives is formed to study how the standard CHC helicopter design might be modified to prolong the flight time without deterioration in stability and flying capacity.

A large number of factors that might affect the flight time are proposed during a brainstorming session, and the list is finally limited to 8 factors which are to be studied through a factorial experiment. The eight factors and their respected levels suggested by the team are listed in Table 1.

The task is to plan, run, analyse and document one or more factorial experiments with the aim to improve the CHC helicopter construction in order to prolong the flight time.

Unfortunately, CHC has a short budget (they have just invested $10 million in a new pilot plant) and does not have resources for more than a total of 25 experimental runs.

The results should be presented in a report directed towards the team of engeneers at CHC. All steps should be motivated and explained in such a way that the experiment can be reproduced and the analysis can be verified by following the report.