Fly_emirates From United Arab Emirates, joined Oct 2000, 1046 posts, RR: 8 Posted (13 years 1 week 1 day 7 hours ago) and read 2417 times:
i was just wondering, when boeing introduced the new 737 generation, and enancing the dc9's into the 717's.. why is it that they did not change the arming and disarming mechanism, and kept them the same way they are! i think it would have been nicer if they did them into an automatic thing. just curious
MD-11 forever From , joined Dec 1969, posts, RR:
Reply 4, posted (13 years 1 week 1 day ago) and read 2293 times:
I remeber to have heard, that the 737NG is not certified as a new design, but certified by a supplemental type certificate. This has the advantage, that the certification specifications are not the latest available ones for systems that you don't change compared to the old design. As an example, the brake system is still following the specifications of the first certified 737 (so late 60's standard).
By using this practise, Boeing is saving a lot of money, as they do not have to go the full certification process for all the systems on the plane.
Don't flame me for this statement, as it is "second hand knowledge", but it makes well sense to me.