Photo/Illutration Mitsubishi Electric Corp.'s logo (Asahi Shimbun file photo)

Mitsubishi Electric Corp. fashioned a computer program to churn out fictitious data used in place of actual tests on air conditioning units it supplied to railway companies apparently for more than three decades.

According to several sources, the program was written to produce numbers that would not raise suspicions about inappropriate testing.

But that could mean that the problem was not an isolated one at the company's Togitsu plant in Nagasaki Prefecture that manufactured the air conditioning units but a much wider, organized deception.

Meanwhile, Mitsubishi Electric officials on June 30 also admitted that inappropriate testing had been conducted on pneumatic devices supplied to railway companies used in braking systems and to operate the train doors.

Company officials said between 1985 and 2020 about 84,600 air conditioning units had been supplied to railway companies, with about 15,800 of those units going overseas.

While officials said they were still trying to determine how many of the units passed through with no testing, they insisted there were no safety or capability problems and that no reports of any mishaps had been received.

But the latest revelation about the pneumatic devices led the transport ministry to issue a notice to railway companies around the nation to conduct thorough checks of their train brakes and to report any malfunctions.

According to several sources, the computer program was used to produce data for a number of different test items. Although no actual tests were conducted, the bogus data generated gave the appearance that they had been done.

The report about the false test data forced railway companies around Japan to check into whether any abnormalities arose in the air conditioning units in their trains.

While none of the companies reported any mishaps caused by the air conditioning data falsification, Toshihiko Aoyagi, president of Kyushu Railway Co., said at a June 30 news conference he felt betrayed by Mitsubishi Electric since it said specifications had been met without carrying out testing.

A majority of the 1,665 train cars used by JR Kyushu have Mitsubishi Electric air conditioning units installed, including Shinkansen. The railway company was notified by Mitsubishi Electric on June 25 that there were no safety problems.

But other companies wanted Mitsubishi Electric to be more specific about which units were supplied without appropriate testing.

(This article was written by Shuhei Shibata and Yoshitaka Ito.)

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