Following a recent status report released by India’s Directorate General of Civil Aviation (DGCA) on problems with the Pratt & Whitney PW1100G-powered Airbus A320neos operated by budget carriers Indigo and Go Air, the regulator has turned its attention to the Boeing 737 Max 8s operated by Jet Airways and SpiceJet.
DGCA, which had imposed strict regulations over and above the OEM's recommendations for the Neos due to engine failures, has chosen to follow a similar agenda following the October 29 crash of a Lion Air 737 Max. While no Indian Max aircraft have experienced any problems associated with the stall-prevention system whose functional characteristics appeared unknown to the pilots to the Lion Air airplane, Reuters quoted a statement by the DGCA on Thursday that pilots in India flying the 737 Max should train on a simulator that replicates the suspected scenario that led to the crash in which all 189 people on board died.
Boeing, in fact, has begun evaluating the need for software changes in the Max following the October 29 crash. According to flight data recorder readouts, faulty angle-of-attack sensor inputs led the flight control system to force the airplane’s nose downward starting two minutes after takeoff and repeatedly until the crash 11 minutes later.
DGCA has asked Jet Airways and SpiceJet, each of which owns Max 8s and has placed an order for 225 and 205, respectively, to turn to manual trimming should the aircraft act in a similar way and land at the nearest airport. If the airplane in question requires any repairs related to its stall-prevention system, it must undergo a verification flight before it carries any more passengers. Once Indonesian investigators issue the final accident investigation report on the Lion Air crash, the DGCA will add further instructions, local newspapers reported.
Meant to improve pitch response at high angles of attack and prevent pilots from raising the airplane’s nose too high, the system found in the 737 Max 8 and Max 9—known as the maneuvering characteristics augmentation system (MCAS)—does not appear in the 737 NG. Engineers made the change to address differing stall characteristics in the Max resulting from its larger and heavier CFM Leap-1B engines. However, pilot groups in the U.S. have said that Boeing failed to communicate with 737 Max operators new procedures for addressing cases in which the airplane’s automatic stall-prevention system commands the nose of the airplane downward.