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If that was all that's needed 737 Max's would all be back in the air by now. There is a fundamental problem in the design. The plane tends to pitch up when acce
by petilon 7y ago
If that was all that's needed 737 Max's would all be back in the air by now. There is a fundamental problem in the design. The plane tends to pitch up when accelerating. Under certain circumstances this can cause the plane to stall and fall out of the sky. This was fixed using software.
Most planes have airframes that are aerodynamically stable in and of itself. The 737 Max requires software assistance to be at the same level of stability.
That, to me, is a fundamental flaw. In a multilayer system each layer needs to be safe in and of itself. The purpose of higher layers is to add functionality not to fix flaws in lower layers.
Given the fundamental flaws in design it was obvious there was a cultural problem at Boeing and the CEO needed to go. "We can't solve problems by using the same kind of thinking we used when we created them." -- Einstein.
- lujim 7y agoI agree with you, but would like one counterpoint. There are plenty of planes that are aerodynamically unstable and require fly by wire/computers for satisfactory flight characteristics. Fighters like relaxed aerodynamic roll stability for roll rate. Now pitch stability issues are troubling. I don't think engineers would purposely relax pitch stability unless they had to. I guess I'm saying you might want an airplane aerodynamically unstable in roll, but pretty much never in pitch so the fly by wire argument might not be valid here.
- jamiek88 7y ago>There are plenty of planes that are aerodynamically unstable and require fly by wire/computers for satisfactory flight characteristics. Not passenger aircraft. Only military.
- na85 7y ago>The plane tends to pitch up when accelerating. They all do this. You have giant engines on the underside of the wing; what else would you expect to happen when you throttle up at low airspeed?
- petilon 7y agoAnd yet only the 737 Max needed a software fix
- na85 7y agoThat's because the pitch-up behavior isn't actually the problem.
- petilon 7y ago[Boeing] engineers observed a tendency for the plane’s nose to pitch upward during a specific extreme maneuver. After other efforts to fix the problem failed, the solution they arrived at was a piece of software — the Maneuvering Characteristics Augmentation System (MCAS) — that would move a powerful control surface at the tail to push the airplane’s nose down. Source: https://www.seattletimes.com/seattle-news/times-watchdog/the-inside-story-of-mcas-how-boeings-737-max-system-gained-power-and-lost-safeguards/ https://www.seattletimes.com/seattle-news/times-watchdog/the...
- na85 7y agoSorry, but the Seattle Times is not a competent source when it comes to reporting aerodynamics. Any standard-configuration airliner will pitch up when you throttle up at low speed.
- inferiorhuman 7y agoThat's because the pitch-up behavior isn't actually the problem. The pitch-power coupling has been problematic on the 737 since Boeing went with GE engines. Thomsonfly almost got a classic to stall in Bournemouth ages ago and flyDubai managed to wreck an NG in Russia a couple years ago. It's possible, but unlikely, the 737 MAX is better behaved in this regard. If there weren't significant aerodynamic problems with the 737 MAX it would be flying by now. This whole type cert / training thing is a red herring. The cost of slow and shuttering production both in financial and diplomatic terms far outstrips the cost of a separate type. Beyond that Boeing has a captive market. The only 737 MAX alternatives out there are made by Airbus, and Airbus has a healthy backlog for both the A220 and A320. While some airlines may be able to take the range / consumption hit with an NG other airlines, like Norwegian, were counting on the increased range of the MAX for certain routes.