Aviation regulator DGCA has asked Jet Airways and SpiceJet to take corrective action to address possible issues with their Boeing 737 MAX planes that could lead to “significant altitude loss” of the aircraft, a senior official said on Thursday.

The latest directive follows advisories issued by US watchdog Federal Aviation Administration (FAA) and Boeing regarding the B 737 MAX planes after the crash of a Lion Air aircraft in Indonesia last month.

Currently, Jet Airways and SpiceJet fly Boeing 737 MAX planes in India. Together, there are at least six such aircraft with the two carriers.

The problem

“Both the documents address erroneous high ‘angle of attack’ (AOA) sensor input and corrective action for the same as it has potential for repeated nose-down trim commands of horizontal stabiliser,” a senior Directorate General of Civil Aviation (DGCA) official told PTI.

The official said that if the condition is not addressed, it could cause difficulty for the flight crew in controlling the airplane.

The condition can even lead to “excessive nose-down attitude, significant altitude loss, and possible impact with terrain,” the official noted.

Based on initial investigation of Lion Air aircraft accident, the FAA issued Emergency Airworthiness Directive (AD) on November 7. Boeing released a bulletin about the issue on November 6.

The DGCA official said that within three days after receipt of FAA AD, changes to airplane flight manual have to be done, for procedures which have to be followed by flight crew.

“The DGCA has ensured that all Indian operators are aware of the FAA AD and have taken appropriate corrective action,” he added.

Comments from Jet Airways and SpiceJet were awaited.

Boeing directive

On November 6, Boeing said it had issued an Operations Manual Bulletin directing operators to existing flight crew procedures to address circumstances where there is erroneous input from an AOA sensor.

On October 30, Civil Aviation Minister Suresh Prabhu said the DGCA had been asked to look at engines and other issues related to airlines following the plane crash in Indonesia.

The DGCA had reviewed the performance of Boeing 737 MAX 8 planes operated by Jet Airways and SpiceJet. The review came a day after a Boeing 737 MAX 8 aircraft operated by Lion Air crashed into the sea shortly after taking off from Jakarta. There were more than 180 people on board.

The watchdog had also sought details about the plane crash from Boeing and US regulator Federal Aviation Authority (FAA).

In September, the minister directed officials concerned to prepare a comprehensive safety audit plan, which involves assessment of safety parameters of all scheduled airlines, aerodromes, flying training schools and maintenance, repair and overhaul organisations.