(Reuters) - Shares of Boeing Co <BA.N> fell on Tuesday on concerns related to last month's deadly crash of a 737 MAX, the newest version of the planemaker's best-selling jet, operated by Indonesia's Lion Air.
Indonesian investigators said on Monday more training was needed for 737 MAX pilots after discovering the situation believed to have faced the crew was not contained in the flight manual. U.S. pilots were also not aware of potential risks, two pilot unions told Reuters.
Boeing shares were down nearly 2 percent at $350.30 in afternoon trade.
Investigators are preparing to publish their preliminary report on the crash on Nov. 28 or Nov. 29, one month after the Lion Air jet dived into the Java Sea, killing all 189 on board.
The accident is the first to be reported involving the widely sold Boeing 737 MAX, an updated, more fuel-efficient version of the manufacturer's workhorse single-aisle jet.
Until now, public attention has focused mainly on potential maintenance problems including a faulty sensor for the 'angle of attack,' a vital piece of data needed to help the aircraft fly at the right angle to the currents of air and prevent a stall.
The investigation's focus appears to be expanding to the clarity of U.S.-approved procedures to help pilots prevent the 737 MAX over-reacting to such a data loss, and methods for training them.
Boeing Chief Executive Dennis Muilenburg told Fox Business Network on Tuesday that Boeing provides "all of the information that's needed to safely fly our airplanes" and that the 737 MAX was a "very safe" airplane.
"This comes out of thousands of hours of testing and evaluating and simulating and providing the information that our pilots need to operate our airplanes safely," Muilenburg said. "In certain failure modes, if there's an inaccurate angle of attack sensor feeding information to the airplane, there's a procedure to handle that."
Earlier on Tuesday, the world's largest planemaker said it delivered 43 of its 737 aircraft last month, up from 37 a year ago, helped by a booming global market. That puts it on track for another year of record deliveries as it battles European rival Airbus SE <AIR.PA>.
Investors and analysts watch the number of planes Boeing turns over to airlines and leasing firms as customers pay the bulk of the money for new planes on delivery.
The number of 737 deliveries was down slightly from the 61 delivered in September due to lingering supplier problems, flagged by a Boeing executive last week.
(Reporting by Sanjana Shivdas in Bengaluru and Eric M. Johnson in Seattle; Editing by Saumyadeb Chakrabarty and Bill Rigby)