For most of the public, the term “experimental flight” means the flying of a new aircraft in order to test its safety. But experimental flights are much more diverse than that, and promote the development of many technologies which we all use and need.
Flight testing does not have to involve a new aircraft
The public is right – many flight tests are indeed performed in order to examine how well an aircraft functions and how safe it is, as well as to verify that it can be used for the purposes for which it was built. However, there are many more uses for such flights in the civil, military and commercial fields, which the public may not yet be aware of. These are becoming more and more frequent as technology evolves.
In fact, these days more planes involved in test flights are not new aircraft being tested, but rather older, reliable planes whose trustworthiness, efficacy and safety have already been proven. Upon such planes, different kinds of systems are installed in order to test them. Normally, they are advanced, sophisticated technological systems which can only be tested for the quality of their operational results by flying them.
A good example for the need for flight testing is when a new radar system is being developed for the purposes of monitoring a country’s borders. Such systems must be as accurate as possible, and provide exact data in order to be useful. Before proclaiming it ready, the developers must make sure that is indeed the case. The best and most efficient way to do this is by flying the system and checking the data it provides against known coordinates at different locations. The system is operated on board an aircraft and the data it provides is compared to the known coordinates, sites in the area, maps, and other data. By doing this, we can verify that the system functions correctly and that its data is true.
Often, a test flight is used for calibration – the adjustment or check of the settings used to make measurements with a tool or system which relies on geographic or topographic data for its operation, or is used to provide such data. This is done in the later stages of development, to verify the accuracy and quality of data that the system will provide.
Aerial mapping, for example, requires the use of highly advanced photography systems and sensors, which must also be tested by flight before their final approval.
Who needs flight tests?
Almost all of the bodies related to the research and development of new systems of all types and in all fields. These may include engineering companies, military industries, geographers and terrestrial surveyors, urban planners and land gauging experts, communication and technology companies, advanced photography equipment producers and many others.
Can any aircraft perform flight testing?
Choosing the aircraft to perform a successful experimental flight depends on the properties of the system designated for testing. Different systems have different features – sizes, weights, shapes and requirements of all kinds. Extra-heavy systems will need flying on an aircraft with more powerful engines, for example. Many systems require special features to be installed on the plane, such as “hard points,” for instance. Hard points are places in the underbelly of the plane which have been fortified by attaching them to the plane’s inner beams. They can carry heavier loads, or have pylons installed on them that can carry these loads.
Photography systems must be flown on an aircraft which would provide them with the widest field of vision possible. For such assignments, many times an aircraft is chosen that has an opening in its underbelly from which a camera can protrude. This way, all of the needed photography can be done with no limitations by the aircraft itself or parts of it.
Certain systems require flying at a higher altitude, and this sometimes makes it necessary to use an air-compressed aircraft – a plane in which there is air pressure that allows regular breathing for those in it, even at high altitudes, just like the passenger planes we all use to fly to our vacations.
And what happens when the team of developers or operators of the system must be present during the experiment to monitor the system’s functioning and reactions? In such a case, a plane must be chosen with a cabin big enough to contain all of the people of the team.
Different planes have different electricity systems that provide various voltage/ amperage. When a system designated for a test flight requires much electricity to operate, the plane has to be chosen accordingly, and to have an electricity system that can provide the needed volumes. In some cases, a modification is needed in order to improve the planes’ electricity system so it can provide the needed energy.
The field of experimental flights is wide and varied, and requires experience, technological and technical knowledge, flexibility of thought, planning and accuracy skills. Airline companies that perform these flights must possess a big aircraft fleet, varied enough to fit every need of every client, as well as employ experienced air crews that are experts in such flights in order to be able to provide successful and effective flight tests.