The civil aviation regulator has said it will undertake a safety assessment of Boeing 737 Max planes flown by SpiceJet and Jet Airways after two unexplained crashes suffered by Ethiopian Airlines and Lion Air of Indonesia in the past five months that claimed 346 lives.

SpiceJet has 11 Boeing 737 Max-8s in its fleet — all of which are operational — while Jet Airways has five, all grounded because of the troubled airline’s inability to pay lessors.

Aviation regulator DGCA has issued additional safety instructions to SpiceJet and Jet Airways for operating these planes. The pilot commanding the aircraft should have at least 1,000 hours of flying experience.

The watchdog has also asked the airlines to ensure that engineering and maintenance personnel comply with various requirements with respect to 737 MAX planes.

On Monday, airlines in China, Indonesia and Ethiopia grounded their Boeing Max 8 planes as a safety precaution.

The Max 8 is the fastest selling airplane in Boeing’s history because it offers a fuel efficiency of 15 per cent over competing planes, translating into a lower seat per mile cost. Boeing has global orders on hand for 5011 Boeing Max planes and has delivered 350 till January this year. The plane first entered service in 2017.

Civil aviation minister Suresh Prabhu said he had directed officials of the Directorate General of Civil Aviation (DGCA) to undertake the safety assessment of the plane. “Safety of the passengers is of utmost concern. I have directed (aviation) secretary and the DGCA to take appropriate action immediately.”

Safety concerns have enveloped the plane after Sunday’s crash of the Nairobi-bound Ethiopian Airlines aircraft soon after taking off from Addis Ababa killing 157 passengers, including four Indians.