patrickjp93 wrote:kalvado wrote:patrickjp93 wrote:Changing avionics architecture would be too big, certainly. Moving from cables to FBW would be too big. Moving from Bleed Air to Bleedless would be too big. Extending landing gear and the minimal geometry changes required while not impacting the handling of the plane should be sufficiently small. The other point to consider is small enough between generations, and probably providing a sunset on common type ratings to be within one generation. In other words, if you hold training on the NG, you can move up to the MAX or down to the Classic with differences training, but if you train for the MAX and have to move to the Classic, you do the full training regimen instead of just differences training as you would for the NG, and your pilot type certificate for the MAX is revoked and replaced with the Classic.
There are easy, sensible ways to manage all of this together. Despite what many on here might consider hubris or paradigm-changing thought on my part, this is simple stuff to think through, analyze, and validate. I'm not a genius, so seriously, think through what I propose and argue on the merits/demerits. It's not like we on here are too stupid to go work at the highest levels of the FAA. The entire structure is based on seniority rather than skill anyway.
Each complex question has a great answer - simple, obvious and wrong.
Let's see how well your position holds water.
From your perspective, how floor strength rating question should be addressed? Modern rules require higer impact strength of cabin floor than what is available on 737 family, and that would be a major redesign. It is not piloting related, it is structural redesign. Cost may approach - or exceed - that of pilot retraining, though. The weaker floor is grandfathered in on MAX as it is only a small change of 737-100.
What kind of changes you think should trigger enforcing that change?
The cost would not exceed pilot retraining and the $1 billion it's now going to cost Boeing in compensating airlines for 1000+ frames at 1 million a pop. Second, this is where regulators and OEMs can work together to improve a grandfathered design without foisting undue secondary consequences from that improvement. Reinforcing the floor beams does not materially change the aerodynamic handling. It may change some rotation inertial moments to a tiny degree, but it uniformly adds weight throughout the fuselage. If that means the wing has to move back one inch to retain CoG over the wing box and thus the handling, fine, but you can still grandfather the common type just fine. It's not much more of a modification than a stretched variant.
You keep mentioning aerodynamics chages - but that is only one part of the deal.
Strength of the structure, weight, seformation/oscillation modes - things may change quite a bit. It is just one thing which may be cost critical - and your response is basically "deal with it... somehow". That makes regulator toothless.
and a billion here, a billion there - we're talking some serious money at the end of the day.