In this file photo taken from a Mainichi Shimbun helicopter on June 4, 2017, a small aircraft is shown after crashing in the mountains of Tateyama, Toyama Prefecture, a day earlier. (Mainichi)

As the number of small aircraft crashes shows no signs of decreasing, the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) solidified plans to test the effectiveness of flight data recorders (FDR) next fiscal year.

An FDR is a device that records flight information such as speed, altitude, the angle of an aircraft's inclination, engine output and steering actions, along with other vital information about the state of the flight, from takeoff to landing. The device, which along with the cockpit voice recorder is often referred to as the "black box," is built to withstand the force of a crash or fire. It not only aids in determining the cause of a crash, but also allows for the analysis of pilots' judgments in flights on a regular basis, which is hoped to help prevent accidents.

The installation of an FDR is only required by the Civil Aeronautics Act for planes that can take flight with a weight of 5.7 tons or over and helicopters with a weight of at least 7 tons which do not belong to the Self-Defense Forces. Small aircraft fall outside of these specifications. However, according to the Japan Transport Safety Board, out of the 1,379 aircraft crashes since 1974, small plane crashes made up about 28 percent at 389, second only to helicopter accidents.

Thus, the MLIT aims to expand FDR use on these aircraft based on the results of the tests. However, a MLIT representative called the installation cost of at least 10 million yen and the complicated task of wiring the device to meters and gauges "a large hurdle to making the devices required by law." But through recent advancements in technology that have resulted in a lightweight simplified device, headway is being made on issues including cost.

The MLIT is seeking volunteers from the roughly 2,300 pilots capable of flying small aircraft nationwide to let the ministry install a simplified FDR in their aircraft in order to test if the device can help identify inappropriate operation of the aircraft that could lead to crashes and other information.

"We would like to analyze just how much merit there is to having the device onboard," a representation from the ministry said.

In recent years, crashes of small aircraft without FDR devices have occurred one after the other. In July 2015, a small plane went down in a residential area in the Tokyo city of Chofu, leaving three people dead and five others injured. The Japan Transport Safety Board presumed from information such as video taken inflight that the crash occurred due to a combination of being overweight and taking off at low speed, but the engine output and decisions made by the pilot were left unclear.

In other recent crashes, such as the June accident in the town of Tateyama, Toyama Prefecture, which claimed the lives of four people, the aircraft did not have flight data recorders onboard.