Commercial airlines operating in Japan will be required from January to employ a doctor to monitor the health of pilots and other crew members, according to transport ministry officials.

The decision was prompted by the 2015 crash of a budget airline jet in the French Alps deliberately caused by the co-pilot, who had a mental illness, the officials said Tuesday. All 150 people on board the Germanwings plane were killed.

While major carriers Japan Airlines Co. and All Nippon Airways Co. already employ specially trained doctors, the Ministry of Land, Infrastructure, Transport and Tourism has decided to require other airlines, including low-cost carriers, operating regularly scheduled services to implement health checkup systems of the same level.

Under current Japanese aviation law, passenger aircraft pilots are obliged to undergo physical and mental checkups at least once a year by government-designated doctors specialized in examining aviation industry personnel.

The transport ministry will impose stricter health care oversight of crew members by requiring all scheduled carriers to employ doctors well-versed in aerospace medicine and familiar with working conditions for pilots and other aircraft crew.

The doctors will be required to take courses in aviation medicine provided by the ministry and to regularly interview all flight crew members. The ministry will also urge airlines to collect information from family members about the health condition of flight crew.

Some budget carriers have already started taking steps to meet the stricter standard. Peach Aviation Ltd. signed up in June a doctor well-versed in aviation medicine while Vanilla Air Inc. is set to sign a contract with such a doctor in the near future.