BOEING: Answering questions

Mr. Black. You ask good questions. You won’t like the answers.

First, let me clarify. I didn’t say that software wasn’t involved but that the software was doing exactly what it was designed to do. The problem that led to the accidents was a system design problem. For example, the data from both AOA sensors was on the data bus, but the avionics wasn’t reading the data from both sensors because it hadn’t been instructed to do so. That’s an easy software fix.

The proximate cause behind both accidents was the MCAS (and not the pilot) commanding nose down in response to a perceived (by the MCAS) stall condition. I think that we aren’t being told the whole story here. According to Boeing, MCAS was created to deal with handling characteristics when the aircraft has partial flap deployment, light weight and CG at the aft limit. Why did they give the MCAS the authority to fly the aircraft? It still has it, by the way, they’re just making it easier to turn it off. How does an aircraft, fully loaded with fuel, passengers, and cargo meet the criteria for MCAS because both accidents happened just after takeoff?

The software fixes are fixing how various systems on the aircraft are working together. How do you know everything is A-OK? You don’t. That’s theoretically why we have the FAA. The Navy has NAS China Lake, Calif. They fly all new software before it’s released to the fleet.

JEFFREY HARRISON

Worley