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Well, they tried to fix an airframe stability problem (caused by fitting larger/heavier engines to an existing airframe platform) with a fly-by-wire solution.

Well, they tried to fix an airframe stability problem (caused by fitting larger/heavier engines to an existing airframe platform) with a fly-by-wire solution. Kinda like if you or I could rent an 18-wheeler truck with a promise that it "drives just like a car." One wonders: Did outside air temperature or weight-and-balance issues figure in to these crashes? Hotter=less lift. Weight too far aft=nose up tendency.

VLM 8y ago
An accurate analogy, although a better HN automobile analogy in the sense of more accessible to the general public would be trying to drive SUVs like cars results in rollover accidents. Its an error of regulation to permit a ridiculously safety critical real world physical system to digitally emulate a historical virtual system to save training money. Its a perfectly good aircraft on its own; it just has intentionally hacked and modified controllers to fake being another plane, and those hacked and modified controls unfortunately kill hundreds of people. Given the merger of government and aerospace its going to be a huge dysfunctional fight where neither side can back down and admit they need to change things. My guess is for purely political reasons both sides will admit guilt, although its obviously completely a government failure. On the other hand, as per the recent VW Diesel situation, if the government implements stupid regulations that are followed to the letter resulting in predictably dumb outcomes, the government accepted no blame and the company was attacked. There are strong indications going both directions which will make this interesting to watch.
- treis 8y ago
  >An accurate analogy, although a better HN automobile analogy in the sense of more accessible to the general public would be trying to drive SUVs like cars results in rollover accidents. That analogy implies that the pilots were trying to fly the plane in a way that it couldn't handle. A better analogy would be a safety mechanism on the SUV that prevents drivers from turning too sharply and rolling over. The crashes are caused by that system incorrectly measuring the turn rate, forcing the car to drive straight, and have it run off the road. Really, there's nothing wrong with the MCAS system in theory. Plenty of planes require computer controlled inputs to fly safely. The problem is in the execution. The base model lacks redundancy and pilots weren't trained well enough to handle the system malfunctioning. And in the case of the Lion Air crash a poor safety culture. Honestly, the problem is probably already solved at this point. Correcting the issue that caused the crashes is simply flipping a switch. The issue is identifying what's causing the control issues to know which switch to flip. Every pilot should be hyper aware of the potential issue and they'll be able to easily diagnose and fix in flight issues.
kayfox 8y ago
The system was designed to correct an issue inherent to all aircraft with podded engines under the wings: nose up tendencies at high power settings. This was inherent in all versions of the 737, it was a bit apparent in the NG, since the new engines make the problem a bit more prominent, MCAS was introduced to correct it. So, its more like an Volvo 18 wheeler which drives just like your Volvo hatchback except when you try to take really sharp turns under power.

VLM 8y ago

An accurate analogy, although a better HN automobile analogy in the sense of more accessible to the general public would be trying to drive SUVs like cars results in rollover accidents. Its an error of regulation to permit a ridiculously safety critical real world physical system to digitally emulate a historical virtual system to save training money. Its a perfectly good aircraft on its own; it just has intentionally hacked and modified controllers to fake being another plane, and those hacked and modified controls unfortunately kill hundreds of people. Given the merger of government and aerospace its going to be a huge dysfunctional fight where neither side can back down and admit they need to change things. My guess is for purely political reasons both sides will admit guilt, although its obviously completely a government failure. On the other hand, as per the recent VW Diesel situation, if the government implements stupid regulations that are followed to the letter resulting in predictably dumb outcomes, the government accepted no blame and the company was attacked. There are strong indications going both directions which will make this interesting to watch.

treis 8y ago
>An accurate analogy, although a better HN automobile analogy in the sense of more accessible to the general public would be trying to drive SUVs like cars results in rollover accidents. That analogy implies that the pilots were trying to fly the plane in a way that it couldn't handle. A better analogy would be a safety mechanism on the SUV that prevents drivers from turning too sharply and rolling over. The crashes are caused by that system incorrectly measuring the turn rate, forcing the car to drive straight, and have it run off the road. Really, there's nothing wrong with the MCAS system in theory. Plenty of planes require computer controlled inputs to fly safely. The problem is in the execution. The base model lacks redundancy and pilots weren't trained well enough to handle the system malfunctioning. And in the case of the Lion Air crash a poor safety culture. Honestly, the problem is probably already solved at this point. Correcting the issue that caused the crashes is simply flipping a switch. The issue is identifying what's causing the control issues to know which switch to flip. Every pilot should be hyper aware of the potential issue and they'll be able to easily diagnose and fix in flight issues.

kayfox 8y ago

The system was designed to correct an issue inherent to all aircraft with podded engines under the wings: nose up tendencies at high power settings. This was inherent in all versions of the 737, it was a bit apparent in the NG, since the new engines make the problem a bit more prominent, MCAS was introduced to correct it. So, its more like an Volvo 18 wheeler which drives just like your Volvo hatchback except when you try to take really sharp turns under power.