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Old 27th Jan 2021, 18:27
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silverstrata
 
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Originally Posted by SRMman
Any comments on the BBC article today.

?
The bottom line here, is that the Max should never have been produced, as it is an ancient dog of an aircraft. But it was pushed down the line because S.outhwest and R.yan wanted a cheap aircraft with lineal commonality. But in truth a 21st century aircraft should never have:

a. Only one sensor controlling a safety system - because that is simply criminaI. Nobody except Boeing has had simplex systems in the last 70 years.

b. A MCAS system that is able to stab-trim fully forwards - when it is known that the stab-trim is more powerful than the elevator. Thus the system has sufficient authority to overpower the pilot, and fly the aircraft into the ground. And if this authority was so easily reduced in the revised Max, then why was this not specified for the original Max? Were there occasional conditions where the system needed full trim authority (for a high-speed stall perhaps), and they are not telling us about it?

c. A manual stab-trimmer that becomes mechanically locked if the pilots are pulling back on the control column - so that no manual re-trimming is possible. (The recommended roller-coaster recovery not being advisable at 2,000 ft, and never taught in the simulator.)

d. An anti-stall device (MCAS) that operates on the stab-trimmer, rather than the control column. Look, dear Boeing, the design and mechanics of an anti-stall device are well-known, ever since the Bae Trident got into trouble. The solution is to push the control column forward, because once the nose is lowered and speed increases, the pressure can be released instantly.
However, if you push forward on the stab-trim, you cannot easily pull out of the ensuing dive because you are still trimmed (fully) forward. (As several pilots have discovered, much to their dismay). So why did the FAA not recommend the complete scrapping of the MCAS system, and the installation of a stick-pusher? Cost? Time? Certification? Has the FAA skimped in their recommended MCAS fix?

e. A master warning system that can be cancelled, so the warnings are extinguished and forgotten. Dimmed perhaps, but never extinguished. This must be the most stupid system ever invented for a commercial aircraft.

f. Important warnings, like low engine oil pressure, that simply don’t appear on the master warning system. It does not take too much in the way of distractions or inattention to miss the fact that the engine is about to seize.

g. Flight controls that cannot be separated if one side is jammed, because the two elevators are joined by a large torque tube. That would not be allowed on a modern aircraft.

h. Engine overheat and fire warning lights that are not in the pilot’s line of sight, with no repeater lights on the thrust levers. Back in 1960 the handles and lights were on the coaming, where they should be, but they were relegated to the center console to make way for the MCP. That was a retrograde fix that should never have been allowed, at least not without repeater lights on the thrust levers. But what do the FAA care, as long as profits are still being made?

i. Switches that are all identical, without even an attempt at colour coding. And the evidence for correct actioning is a light that goes bright and dim. Now between day and night, just what is bright and what is dim? Never in the history of aviation has there been such a stupid advisory/warning system.

j. Switches which are all down for on - unless they are on the forward and center instrument panels, where they are up for on. Note that the all-important electric trim cutoff switches are down for off - the complete opposite to the majority of switches on a 737. There is so much room for confusion here, you could drive a semi-trailer through it.

k. Paper checklists and emergency checklists. Now come on guys and gals, computer checklists were common back in the 80s, so why the hell are we still operating with bits of crumpled and torn paper?

l. Mainwheels that retract into the hydraulics and flight-controls bay, where shredded tyres can inflict severe damage on a multitude of systems. Some airlines placed cages in the wheel-bay to protect the systems, but they did make routine maintenance difficult. And the hydraulic release fuses were hardly an adequate solution to a failed 1960s design.

m. Center fuel pumps in the center tank, which can overheat and explode - and no auto-switching system was devised to prevent this. Has this been solved on the Max, because it was a butcher’s bin on the NG?

n. Passenger doors that have to be armed by grovelling on the floor. This is rather like having a starter-handle on a modern car.

o. Flight-deck windows that are smaller than an old-fashioned cruise-liner port-hole, because that was all they could make in 1950. Trouble is, we are in 2021 now.

I could go on, but that is sufficient for now.
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