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Introduction

March 28, 2019, © Leeham News: Boeing 737 MAX pilots learning about the revised software upgrade to the Maneuvering Characteristics Augmentation System (MCAS) will need a half hour of computer-based training (CBT), the company told the media yesterday in a briefing.

Pilots of the 737 NG who have not yet made the transition to the MAX also have to be trained on the MCAS now. Boeing did not specify if this will take longer than those already trained on the MAX.

• Related article: Boeing presents MCAS software fix details

Summary

• No estimate to MAX return to service.
• Waiting for investigations of the crashes.
• More information for pilots.

Discussion

A Boeing official, speaking on background, said the amount of training time between the MAX and NG pilots dictates how much training time on MCAS will be required.

“If you’re a fully qualified NG pilot, you have to take all the differences training between the NG and the MAX,” the official said. Before the Lion Air and Ethiopian Airways accidents, this was limited to about one hour on an iPad, according to press reports. It’s unclear now if this will be greater following the accidents.

“If you’re a fully qualified MAX pilot, all you have to take is computer-based training around the upgrade. The upgrade package is something that is on the order of about half an hour,” the official said.

The officials said that the software upgrade functions are “invisible” to the flight crew.

“What we present to the flight crew is a system where the MCAS is operating properly. The NG and the MAX fly exactly the same. You would not be able to discern the differences between the two airplanes.”

There is no simulator training required. Only with a failure of the MCAS would warning signs appear on the instruments, the official said.

What went wrong?

Boeing wasn’t prepared to acknowledge its design was “wrong,” leading to two fatal accidents.

“First, we don’t have a cause yet,” the official said, of either accident. “Most accidents are the result of a chain of events. If any one of those links in the chain is broken, the accident doesn’t occur. We can go back and look at all the links in the chain and ask questions about each of those links.”

The official said that industry standard and practice classify failures in hazard categories. Systems are then designed around how these failures are classed.

“One of the ways you assign the failures is to understand what happens after that failure occurs. There are class of failures for which the mitigation of that failure can be quickly performed by a trained pilot using standard procedures,” the official said.

In these cases, a single input (in this case, one Angle of Attack sensor), is allowed.

“It’s a balance between complexity and availability of function,” he said.

The official said that although no final reports have been issued, the interim report in the Lion Air accident provided a look at the link in the chain that could be made more “robust. That’s what we’re doing.”

More information

In an earlier global conference call, Boeing said it will provide detailed information for the pilot’s manual and computer-based training outlining the MCAS procedures and functionality; and a flight operations technical bulletin to supplement the CBT and manuals.

“All 737 MAX pilots will complete this training prior to returning to flight,” Boeing said.

“We are very confident all of the software updates meets our intent” at improving the MCAS, Boeing said on the conference call.

Certification

Boeing was asked on the conference call if Boeing employees, acting in their role as designees for the US Federal Aviation Administration, will be certifying the MCAS software upgrade.

The official ducked this direct question twice, saying only that the FAA will follow its standard processes and procedures.

Boeing said it isn’t changing the AOA indicator, noting this hardware is on four types of Boeing aircraft besides the MAX with tens of millions of hours of experience with them.

Boeing is changing the processing of the data from the AOAs as part of the updates to the MCAS functionality “so that we’re comparing inputs from both Angles of Attack sensors and if those inputs disagree by more than a certain amount…we disable MCAS.”

There is no estimate when the grounding orders will be lifted by regulators throughout the world. The FAA doesn’t want to act unilaterally. EASA of Europe and Transport Canada specifically said they want to review the fix.

China was the first to ground the airplane and refused to certificate the 737 on a plane-by-plane process—something it did last year with Airbus for political reasons.