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This is actually the problem. If they were willing to change the type certification, they would have been free to raise the airplane up and keep the engines in

This is actually the problem. If they were willing to change the type certification, they would have been free to raise the airplane up and keep the engines in their proper position. The need to keep type certifications the same is the root cause of a whole series of bad decisions, including engine placement and the unwillingness to change pilot training & documentation.

rootusrootus 6y ago
> free to raise the airplane up How do you suppose they might do that without completely redesigning the plane? I don't think type recertification is why they kept the landing gear the same length.
- ashtonkem 6y ago
  There certainly would be other costs associated with that, but the primary motivator for not redesigning their aircraft was maintaining type certification, not the cost of a clean redesign. If the Max8 could keep the same type certification, pilots could cross over without long and expensive training, and without losing their rating on their prior aircraft, making adoption a no brainer. If the Max8 doesn’t keep a type rating, there’s less of an incentive for current 737 customers to buy a Max8, since they’ll have to go through the same logistical hurdles that introducing a A321neo would have. Plus Southwest basically won’t buy anything but 737s, so maintaining that type rating was critical to selling the new plane to one of their biggest customers.
- selectodude 6y ago
  It absolutely is. Boeing already made a stretched 737 with larger engines. It's called the 757 and they stopped making it because airlines wanted bigger 737s.
  - rootusrootus 6y ago
    Lengthening the landing gear is a non-trivial design change. It might be more feasible to shorten the fuselage on a 757 than reengineer the gear on the MAX.
    - ashtonkem 6y ago
      The point is not “raising the vehicle height would be cheap”; it obviously wouldn’t. The point is that one of the key requirements was maintaining the 737 type certification. If that requirement was thrown out, they would’ve made a better airplane that wouldn’t have sold anywhere near as well as the MAX8.
      - deleted 6y ago
        [deleted]
  - kayfox 6y ago
    Since the 787 is somewhat a clean sheet redesign of the 767, Boeing wants to do the same with the 757 and is currently trying to get the traction with airlines to do that. Boeing had initially proposed a clean sheet redesign of the 737, but the market for that aircraft is very sensitive to training and operation costs.
    - selectodude 6y ago
      As of very recently they’re looking into putting new engines under a 757 and adding some carbon composite for lightness. They’re referring to it as the 757-Plus.
      - ashtonkem 6y ago
        That’s basically what airbus did to create the A320neo series; add in larger engines (including the same one the MAX8 uses, actually), and make a few minor tweaks to improve weight or aerodynamic efficiency. Done correctly it’s a brilliant move; 15-20% fuel savings without the need to significantly change pilot or maintenance (sans engines) protocols. Sadly the MAX8 was not done correctly.

rootusrootus 6y ago

> free to raise the airplane up How do you suppose they might do that without completely redesigning the plane? I don't think type recertification is why they kept the landing gear the same length.

ashtonkem 6y ago
There certainly would be other costs associated with that, but the primary motivator for not redesigning their aircraft was maintaining type certification, not the cost of a clean redesign. If the Max8 could keep the same type certification, pilots could cross over without long and expensive training, and without losing their rating on their prior aircraft, making adoption a no brainer. If the Max8 doesn’t keep a type rating, there’s less of an incentive for current 737 customers to buy a Max8, since they’ll have to go through the same logistical hurdles that introducing a A321neo would have. Plus Southwest basically won’t buy anything but 737s, so maintaining that type rating was critical to selling the new plane to one of their biggest customers.
selectodude 6y ago
It absolutely is. Boeing already made a stretched 737 with larger engines. It's called the 757 and they stopped making it because airlines wanted bigger 737s.
- rootusrootus 6y ago
  Lengthening the landing gear is a non-trivial design change. It might be more feasible to shorten the fuselage on a 757 than reengineer the gear on the MAX.
  - ashtonkem 6y ago
    The point is not “raising the vehicle height would be cheap”; it obviously wouldn’t. The point is that one of the key requirements was maintaining the 737 type certification. If that requirement was thrown out, they would’ve made a better airplane that wouldn’t have sold anywhere near as well as the MAX8.
    - deleted 6y ago
      [deleted]
- kayfox 6y ago
  Since the 787 is somewhat a clean sheet redesign of the 767, Boeing wants to do the same with the 757 and is currently trying to get the traction with airlines to do that. Boeing had initially proposed a clean sheet redesign of the 737, but the market for that aircraft is very sensitive to training and operation costs.
  - selectodude 6y ago
    As of very recently they’re looking into putting new engines under a 757 and adding some carbon composite for lightness. They’re referring to it as the 757-Plus.
    - ashtonkem 6y ago
      That’s basically what airbus did to create the A320neo series; add in larger engines (including the same one the MAX8 uses, actually), and make a few minor tweaks to improve weight or aerodynamic efficiency. Done correctly it’s a brilliant move; 15-20% fuel savings without the need to significantly change pilot or maintenance (sans engines) protocols. Sadly the MAX8 was not done correctly.