Just several days ago we witness Boeing Aircraft Manufacture test fly it's maiden voyage of the B-787 Dream liner. The B-787 is a revolutionary concept. It's been build almost entirely with composite carbon fiber, or in other words plastic. This concept is not new. There are some military aircraft, & corporate aircraft that have this design too. The purpose of these composite materials is to make the aircraft more fuel efficient which will equate to greater savings to the consumer in the future. The Boeing test flight was conducted by Test pilot & Capt Mike Carriker. The testing has several areas such as ground testing, simulator testing, & finally flight testing.
Some of the things that goes on during a test flight is actually performed in a simulator first. With FAA guidance & approval the test are moved to ground test such a high speed acceleration & aborted takeoff. They also test for structural integrity of the engines to see if the engines can survive several direct impacts from large birds. Once they go through the flight test portion which is sometimes called the proving runs, they further check aircraft performance & compare it to what they calculated. For example, they want to know how well an aircraft performs in a real hot or cold environments of the country. They test to see how well it performs in high elevation airports with one engine. They test other flight characteristics. All the research is done by test pilots is compiled into data to create the aircrafts's flight operating manual or pilot operating manual. In this book consists of all the things the airplane is capable of doing & any restriction of limitations that you shouldn't do. One example would be a limitation of not using the speed brakes below 180 knots. Speed brakes are used to kill lift & slow the aircraft during the descend. In this example, the test pilots & engineers might use a fudge factor & place a limitation that you can't use speed brakes below 200 knots. The flight test continues on for several months. Once finish, the test aircraft or prototype gets approved by the FAA & is awarded a type-certificate for production.  Boeing Aircraft Company been around for over 70 years & is one of the top aircraft makers in the world. Most pilots love Boeing arcraft. So you can rest assure that your future flight went through a rigorous testing course. There a saying in the industry," If it ain't boeing & I'm not going".