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The primary design objective of the 737 max was to avoid pilot retraining. Until that stops being a major economic driver in aviation no problem was solved here

The primary design objective of the 737 max was to avoid pilot retraining. Until that stops being a major economic driver in aviation no problem was solved here. Changing MCAS another dozen times and updating the manuals does nothing to prevent this from happening in new future system design.

sokoloff 7y ago
There’s a tension between progress (some of which offers fuel [and ecological] savings) and cost. If you can make a plane that saves an airline $1MM/year/copy but costs them $4MM extra and $500K/yr in training costs, you won’t sell as many as if it costs them $3MM extra and requires no retraining (or even $5MM/$0). Sometimes that difference is enough to make the project not viable economically. Certification is incredibly expensive. The airplane I fly the most was built in 1997 on a type certificate (the basis of certification) originally approved in 1958. That’s incredibly common. Passengers complain about terrible seats, terrible service, jam packed flights and then search for tickets on price as the overwhelming factor. It’s little surprise that airlines are competing mostly on price. I’m not sure what you’re suggesting here as the solution to make it [pilot re-training?] “not a major economic driver”. It could be “reduce training costs for everyone” or “increase training costs for everyone” or something else.
- ed312 7y ago
  Airline flights, and international travel generally, is _incredibly cheap_ compared to basically all human history. Adding in just a little more cost for a measurable, significant safety benefit seems like an obvious choice.
- londons_explore 7y ago
  This problem would be resolved if type certifications expired. Eg. A newly certified plane type can be produced for 15 years before requiring recertification to new standards. In effect, this forces Boeing to come up with new designs, since the chances of old designs meeting new standards are low. It'll give them a big incentive to find ways to get the cost of certifications down. Up to them if they choose to evolve the plane with the standards, or do a ground-up redesign every 15 years.
  - ceejayoz 7y ago
    New designs tend to have new issues. The pre-MAX 737s tend to be remarkably safe because the inherent mechanical issues have been detected and fixed over billions of flight hours.
  - mannykannot 7y ago
    > It'll give them a big incentive to find ways to get the cost of certifications down. That is exactly what went wrong in the 737 MAX process -- the goal was achived by using political pressure to weaken the oversight. With proper oversight, type-certificate extension is a sound process. Without it, no form of certification is effective.
  - sokoloff 7y ago
    That's an interesting proposal. Thanks for bringing it forward. It would certainly increase costs in the industry and might introduce discontinuities in the pilot supply, particularly during irregular ops (weather delays causing crew timeouts causing crew substitutions) when pilots of 2015-era narrowbody jet #7 can't fly the 2014-era narrowbody jet #7 because the type rating is different or we have to stuff into their brains the qualifications for both the pre- and post- and have them alternate recurrent training between the two types, which brings its own safety concerns as compared to sending the crew to only one type of recurrent every required period. Alternatively, we might address that by giving a common type rating to the aircraft (such as with the 757 and 767, which share a common type rating [the pilot qualification basis] today despite being built on different type certificates [the aircraft certification basis]), which would allow for common recurrent training with just differences training across models/series.
joehosteny 7y ago
There's a lot of safety value in not having to be retrained, too.
- maxerickson 7y ago
  It's sort of key when taking that approach to actually succeed in not requiring the retraining.
  - joehosteny 7y ago
    Of course. That’s pretty common though, and you don’t hear about when that is successful. As an example, the 757 and 767 share a common type rating.
- situational87 7y ago
  The safety value proposition of the max is kind of hard to sell after two planes crashed. It was already the most successful plane ever in terms of avoiding retraining right? All that unlocked safety value didn't count for much.
sambull 7y ago
It's not just limited to pilot retraining. It's also about the rating on the air-frame, and grandfathering in saftey features/systems etc that wouldn't cut it on modern reviews, like the doors.

sokoloff 7y ago

There’s a tension between progress (some of which offers fuel [and ecological] savings) and cost. If you can make a plane that saves an airline $1MM/year/copy but costs them $4MM extra and $500K/yr in training costs, you won’t sell as many as if it costs them $3MM extra and requires no retraining (or even $5MM/$0). Sometimes that difference is enough to make the project not viable economically. Certification is incredibly expensive. The airplane I fly the most was built in 1997 on a type certificate (the basis of certification) originally approved in 1958. That’s incredibly common. Passengers complain about terrible seats, terrible service, jam packed flights and then search for tickets on price as the overwhelming factor. It’s little surprise that airlines are competing mostly on price. I’m not sure what you’re suggesting here as the solution to make it [pilot re-training?] “not a major economic driver”. It could be “reduce training costs for everyone” or “increase training costs for everyone” or something else.

ed312 7y ago
Airline flights, and international travel generally, is _incredibly cheap_ compared to basically all human history. Adding in just a little more cost for a measurable, significant safety benefit seems like an obvious choice.
londons_explore 7y ago
This problem would be resolved if type certifications expired. Eg. A newly certified plane type can be produced for 15 years before requiring recertification to new standards. In effect, this forces Boeing to come up with new designs, since the chances of old designs meeting new standards are low. It'll give them a big incentive to find ways to get the cost of certifications down. Up to them if they choose to evolve the plane with the standards, or do a ground-up redesign every 15 years.
- ceejayoz 7y ago
  New designs tend to have new issues. The pre-MAX 737s tend to be remarkably safe because the inherent mechanical issues have been detected and fixed over billions of flight hours.
- mannykannot 7y ago
  > It'll give them a big incentive to find ways to get the cost of certifications down. That is exactly what went wrong in the 737 MAX process -- the goal was achived by using political pressure to weaken the oversight. With proper oversight, type-certificate extension is a sound process. Without it, no form of certification is effective.
- sokoloff 7y ago
  That's an interesting proposal. Thanks for bringing it forward. It would certainly increase costs in the industry and might introduce discontinuities in the pilot supply, particularly during irregular ops (weather delays causing crew timeouts causing crew substitutions) when pilots of 2015-era narrowbody jet #7 can't fly the 2014-era narrowbody jet #7 because the type rating is different or we have to stuff into their brains the qualifications for both the pre- and post- and have them alternate recurrent training between the two types, which brings its own safety concerns as compared to sending the crew to only one type of recurrent every required period. Alternatively, we might address that by giving a common type rating to the aircraft (such as with the 757 and 767, which share a common type rating [the pilot qualification basis] today despite being built on different type certificates [the aircraft certification basis]), which would allow for common recurrent training with just differences training across models/series.

joehosteny 7y ago

There's a lot of safety value in not having to be retrained, too.

maxerickson 7y ago
It's sort of key when taking that approach to actually succeed in not requiring the retraining.
- joehosteny 7y ago
  Of course. That’s pretty common though, and you don’t hear about when that is successful. As an example, the 757 and 767 share a common type rating.
situational87 7y ago
The safety value proposition of the max is kind of hard to sell after two planes crashed. It was already the most successful plane ever in terms of avoiding retraining right? All that unlocked safety value didn't count for much.

sambull 7y ago

It's not just limited to pilot retraining. It's also about the rating on the air-frame, and grandfathering in saftey features/systems etc that wouldn't cut it on modern reviews, like the doors.