<story><title>Boeing whistle-blower says proposed 737 Max fixes aren&apos;t enough</title><url>https://www.bloomberg.com/news/articles/2020-09-21/boeing-whistle-blower-says-proposed-737-max-fixes-aren-t-enough</url></story><parent_chain><item><author>tzs</author><text>Question: my understanding is that the purpose of MCAS is to make the 737 MAX behave very similar to prior 737s in some unusual flight situations. There are two main reasons for this:&lt;p&gt;(1) Existing 737 pilots would not need to be recertified for the MAX. They would just need to read a short document that updated the procedure for handling runaway trim.&lt;p&gt;This would make the plane more attractive to airlines because it meant not having to pay for expensive recertification of pilots, and&lt;p&gt;(2) The plane itself would not need to be certified as a new aircraft type. The requirements for certifying new tapes change over the years, and older planes like the 737 would not meet today&amp;#x27;s requirements. By making it fly similar enough to the existing 737s, it could be classified as a variant on the existing model and be grandfathered in on the old certification.&lt;p&gt;Certifying a new type is very expensive and takes a long time.&lt;p&gt;My question is this: how long does the MAX have to be grounded before the costs of it not being service end up more than (1) the costs of recertifying pilots, and (2) the costs of making the other design changes that would be needed to certifying as a new type under current rules and then getting it certified?</text></item></parent_chain><comment><author>Animats</author><text>By now, it would have been cheaper to put in a proper triple or quad redundant flight control system and have pilots retrain for the type than to ground the fleet and lose orders.&lt;p&gt;The bad decisions that led to this are well known. Southwest Air has a business model based on having only one type of aircraft, the Boeing 737. They insisted that the 737 Max behave exactly like the other 737 models, and not require that pilots be trained and rated for two different aircraft. So Boeing tried to make Southwest happy.&lt;p&gt;A deeper bad decision is that Boeing doesn&amp;#x27;t have a 737 replacement. The original 737 is from the 1970s. By now, Boeing should have had a new plane out in that size range. Airbus does. COMAC is coming out with one, if it works well. But Boeing guessed wrong on the sizes of aircraft airlines would want. They thought the future was widebody, not mailing tubes full of seats. The 767, 777, and 787 are all widebodies. So, of course, was the 747. The 757 was a great airplane for passengers and pilots that airlines didn&amp;#x27;t want because it cost more and used more fuel. So Boeing had a huge lineup of widebodies, and no good competitor for the Airbus narrow-body options.&lt;p&gt;Hence the 737 MAX, a 737 with engines too big for the airframe and a software kludge to compensate for that.</text></comment>
<story><title>Boeing whistle-blower says proposed 737 Max fixes aren&apos;t enough</title><url>https://www.bloomberg.com/news/articles/2020-09-21/boeing-whistle-blower-says-proposed-737-max-fixes-aren-t-enough</url></story><parent_chain><item><author>tzs</author><text>Question: my understanding is that the purpose of MCAS is to make the 737 MAX behave very similar to prior 737s in some unusual flight situations. There are two main reasons for this:&lt;p&gt;(1) Existing 737 pilots would not need to be recertified for the MAX. They would just need to read a short document that updated the procedure for handling runaway trim.&lt;p&gt;This would make the plane more attractive to airlines because it meant not having to pay for expensive recertification of pilots, and&lt;p&gt;(2) The plane itself would not need to be certified as a new aircraft type. The requirements for certifying new tapes change over the years, and older planes like the 737 would not meet today&amp;#x27;s requirements. By making it fly similar enough to the existing 737s, it could be classified as a variant on the existing model and be grandfathered in on the old certification.&lt;p&gt;Certifying a new type is very expensive and takes a long time.&lt;p&gt;My question is this: how long does the MAX have to be grounded before the costs of it not being service end up more than (1) the costs of recertifying pilots, and (2) the costs of making the other design changes that would be needed to certifying as a new type under current rules and then getting it certified?</text></item></parent_chain><comment><author>V_Terranova_Jr</author><text>To answer this, you&amp;#x27;d need to compute the costs of the up-front engineering associated with trying to re-certify as a new type, and also the costs of the modifications.  Additionally, there&amp;#x27;s always negotiation in the certification process: how will the manufacturer substantiate compliance, and if they can&amp;#x27;t, can they convince the regulator that the regulator&amp;#x27;s intent has been &amp;quot;met&amp;quot; within some acceptable level of risk?  That can&amp;#x27;t be rigorously computed until the dialog with regulators takes place.&lt;p&gt;I don&amp;#x27;t know that Boeing has computed likely values of such costs, and that if they did, that they would allow them to be publicly known.  Moreover, Boeing would probably focus on their worst-case numbers to justify to everyone why the only viable path is to minimally modify the design.</text></comment>