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The main driver is the desire to make engines bigger, thus more fuel-efficient. The fuel savings of the newest engine generations are significant. If you hang e
by _ph_ 5y ago
The main driver is the desire to make engines bigger, thus more fuel-efficient. The fuel savings of the newest engine generations are significant. If you hang engines from your wings (I assume that has practical reasons, it is easier to hang the engine than include it into the wing, it is also easier to maintain), larger engines mean engines further from the axis. That applies to all modern airplanes which share this configuration. A complete redesign of the 737 wouldn't have made this go away either. However the goal of keeping the same type rating made the especial design of MCAS necessary.
- missedthecue 5y agoNon-engineer here. What's wrong with taller landing gear to provide more clearance?
- hasperdi 5y agoIn 737 case, it means redesign of the landing gear system, fuselage modifications, recertification, retraining, new support system requirements eg. Higher stairs, cargo support equipment etc.
- himinlomax 5y agoYou also can't put longer main gear: as they fold inward, they have to attached at points separated by over twice the height. If you move them apart, you have to make the center fuselage as well as the root of the wings much stronger. That's a much bigger change than anything else.
- adgjlsfhk1 5y agoTaller landing gear makes loading the plane (especially with luggage) much harder.
- himinlomax 5y agoI believe they altered the landing gear so it extends upon deployment, giving it a bit more height, but that's not enough. They can't just put longer legs, there isn't enough room. There's stuff there (cables, devices, bulkheads ...) and moving them requires a significant redesign. For the main gears, they would have to be attached further away from the center lest they bump into each other, which means the wings and fuselage would have to be stronger to accommodate for it. Very quickly you're just designing a new plane.
- missedthecue 5y agoWhat about telescoping landing gear?
- _ph_ 5y agoThe thing is, this wouldn't have magically solved the issue. Larger engines hanging from your wing fundamentally affect the balance of an airplane. Take the thrust vector for example. The further you move the engine from the longitudinal axis of the plane, the stronger the angular momentum is, that is exercised from the engines onto the plane, especially when pitching up.