Boeing 737 Max Certification Focus of Far-Reaching NTSB Probe

The U.S. National Transportation Safety Board is conducting a far-reaching review of how Boeing Co. certified the 737 Max system that has been involved in two crashes, going beyond the typical low-profile assistance they provide in foreign accident probes.

The investigation, which is more extensive than has previously been reported, could result in safety recommendations that would have significant implications in the way aircraft are certified in the wake of the grounding of Boeing’s best-selling jetliner after the crashes in Ethiopia in March and in Indonesia last October.

“We’re going to follow the facts wherever they lead,” said NTSB spokesman Eric Weiss. “We’ve traveled. We’ve collected data. We’ve conducted interviews.”

NTSB investigators held multiple interviews with Boeing and Federal Aviation Administration officials earlier this year to gather information on how a flight-control system that was automatically driving down the nose on both planes, according to a person familiar with the probe who wasn’t authorized to talk about it.

The safety board has no regulatory power, but it can make non-binding recommendations if it finds that there were lapses in the approval process or there were other safety issues. Those recommendations have in the past led to congressional action or regulatory changes, and can have greater effect in high-profile cases such as the one involving the 737 Max.

The model was grounded by the FAA on March 13, three days after the second fatal crash in less than five months. In both accidents, which killed a total of 346 people, a software add-on to the flight controls was automatically and repeatedly commanding the planes to dive as a result of a malfunction. Pilots were eventually overwhelmed by the system and the planes dove at high speeds, killing all aboard.

The NTSB works on dozens of international investigations each year and normally performs its work in the background. By treaty, nations in which a plane crashes are in charge of the investigations and the safety board’s role is to assist.

But the agency has occasionally used foreign cases as a platform for recommendation letters to manufacturers and regulators.

“Because the United States is the state of design and certification of the aircraft involved in these accidents, we are examining relevant factors in the U.S. design certification process to ensure any deficiencies are captured and addressed, including by NTSB safety recommendations, if necessary,” NTSB Chairman Robert Sumwalt said in written testimony before the House aviation subcommittee on May 15.

He said the agency may end up issuing recommendations, something it has done a handful of times in foreign accident investigations.

In March 2009, for example, the NTSB issued an urgent safety recommendation to the FAA seeking a redesign of a Rolls-Royce Holdings PLC engine on Boeing’s 777 following a crash- landing in England a year earlier. Ice had formed in the engine’s fuel system on Jan. 17, 2008, causing both power plants to lose thrust and the jetliner to land in a field short of a runway at Heathrow Airport.

In spite of such previous cases, the NTSB’s power to conduct investigations in foreign accidents isn’t as clear as in domestic crashes, in which the agency has broad legal authority. Indeed, there has at times been tension in recent months between FAA and NTSB as the safety board explores the 737 Max, according to the person familiar with the probe.

Boeing is working with the FAA, which regulates aircraft manufacturers such as Boeing, to update the plane’s software and training requirements. The FAA must approve those fixes before agreeing to allow the plane to resume operations.

In the wake of the grounding, numerous investigations and review panels were initiated.

The U.S. Justice Department’s Criminal Division has begun an inquiry and subpoenaed records on the plane. The Transportation Department’s Inspector General, which is assisting in the criminal investigation, has begun a separate review of how the plane was certified.

In addition, the DOT has a blue-ribbon panel examining certification and the FAA’s use of Boeing employees to conduct some safety assessments. A panel known as the Joint Authorities Technical Review, made up of experts from nine other countries, is reviewing the 737 Max’s certification.

A Technical Advisory Board will also review Boeing’s proposed fix before FAA gives its approval.

“We continue to fully support the investigating authorities,” Boeing spokesman Charles Bickers said.

The NTSB’s work assisting the Indonesian and Ethiopian authorities has been under a treaty known as Annex 13. In that agreement, the country in which an aircraft is designed and built has the authority to participate in an investigation.

“This is consistent with our Annex 13 responsibilities,” Weiss said of the NTSB work on the 737 Max. “If we find areas of interest or concern that could lead to safety improvements and recommendations, we have pursued those areas in past investigations.”