THE first of the modern flight-testing-equipment installations was made in the Douglas DC-4E. In the tests of this airplane, Mr. Dickinson says, all data were recorded manually, except that two cameras were used for some special tests. The test equipment was so extensive that the flight crew always had from 12 to 22 men. The undesirability of carrying such a large crew, the necessity for continuously recorded data, and the fact that the need for data is often not sensed until after the test, made it desirable to develop some sort of mechanical recording means to take over as much of the recording job as possible.
The flight-testing equipment for testing modern large airplanes, such as the XB-19, has been developed to the point where the small crews now required do not need to record any of the data. Back in the sleeping compartment, completely unattended, automatic flight recorders and an automatic temperature recorder system continuously gather all possible information on the operation of the engines, controls, and performance of the airplane.
To take care of the flight-test equipment, it is necessary to design the interior specially. This interior protects the airplane and provides solid anchorage for every piece of equipment and ballast that might come loose in maneuvers.
All in all, the test instruments, interior furnishings, wiring, tubing, batteries, and electrical accessories for one installation weighed nearly 11,000 lb and cost $38,600, exclusive of the cost of labor to install.
