Like all chat rooms, thr pprune.org professional pilots site has its fair share of disagreements and bashing of some posters’ comments. This one (post 2333) by a pilot about the way Boeing has developed the various versions of the 737 aircraft is worrying. Less perhaps to the traveling public because the “cobbling together” of improvements has generally not resulted in accidents, and more to Boeing itself if the details become public in the course of various lawsuits.
The post was made in response to another about Boeing pushing the Max version out too speedily using band aids rather that a redesign - all to catch up with the Airbus Neo programme. He suggests the MCAS system was a quick software fix to counter a “basically unstable platform.” He goes on -
In my humble opinion, they [Boeing] should have started again with the 73 about the time of the -300/-400 and completely redesigned it. As it stands, they seem to have cobbled together systems as they became available or desirable and bolted them where they could find space. (The computer fuel summing unit - cant remember its exact name - is fixed outboard above the F/Os head - why not in the avionics bay?). The F/Os seat cannot be moved vary far back because of the C/B rack behind it. The elevator feel unit has its own pitot probes each side of the fin.
I only have experience of the -300/-400, but that aircraft is a mish-mash of mechanical and electronic devices, seemingly not properly integrated, but just about working. The Classic autopilot does not trim ailerons or rudder, so when you take out the autopliot you often have to spend a mile or so on short finals getting the thing trimmed. The Cockpits of the -300/-400 look as if they were designed by firing a shotgun at a blank panel, and fitting the instruments and indicators whereever there was a handy hole. Generators have to be manually switched on to the buses. Later models without the round generator dials, still use the old panels with the cut-outs for the round dials rather than making a new panel....how cheap is that?
It seems to me that as each new requirement or problem came along, instead of doing a redesign, Boeing developed a standalone fix or widgit to solve the problem - but they dont appear to have always thought it through in terms of the way the whole aircraft works, or how the pilots would interface with it.
As to why the 73 is so popular, I think South West have a lot to do with that, (they are also indirectly partly responsible for the arrested development of the 73). I have been told that Boeing also have some very creative fleet purchasing schemes for airlines.
As to MCAS, instead of affecting the THS trim, why not simply have it modify the elevator feel at hiigh AoA - which is, after all, the problem caused by the engine nacelles. Or insert a gentle down input to the elevators? But not the trim. Secondly, why have only one AoA probe, or even two? For such a critical device, why not have five?
Sorry I don’t know the meaning of some of the terms, but I think the gist of the post is more than obvious.