Hacker News Reader

Comment by WalterBright | Hacker News Reader

There's nothing wrong with the 737MAX airframe. It's a software problem with the MCAS system.

Unassisted non-compliance with FAR 25.173 begs to differ.

Keep in mind MCAS would not have existed to malfunction if the airframe was capable of complying with existing regulations unaided.

This fact alone means that the airframe does have something wrong with it.

FAA regs require an active yaw damper, because all swept wing airliners would be dangerously unstable without it.

There is no difference in principle here with the MCAS system.

Except that unstable pitch is more dangerous than yaw?

Yaw instability has resulted in fatal crashes.

I disagree that this is only a software issue: relying on only one sensor is a system issue in the MCAS not a software issue.

The worst part is that there is only one sensor because having only one sensor allowed them to not document it and requiring pilot retraining. They just found a loophole to exploit, it had nothing to do with a single sensor being a good decision.

Some might argue the engine placement is very awkward to accomodate the low slung wings. With predictable outcomes, like MCAS.

Swept wings are also unstable, requiring a yaw damper, and crashes have resulted from inoperative yaw dampers.

Of course, we could demand a return to straight wings, but then air travel would be a lot slower.

The low mounted wings on the 737 are serving a no longer needed niche. They were there to accommodate rolling air stairs, where you walk into the tarmac and walk up aircraft-internal steps to board the plane.

The last time I flew on a 757 (a couple months ago) I got on and off on the rolling air stairs.

Rolling is different, I shouldn't have used that term. The 737 can be deplaned with stairs that are integral to the aircraft.

Ryanair does still use the internal 737 stairs at some airports in Europe.

Reply on news.ycombinator.com