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Scheny

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I heard that the newest 737max problem is deactivating the flight director if the stick shaker activates. To avoid an undefined state, the flight director and autopilot would have to turn themselves off on their own. So, no toggle switch anymore.
 
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Urquiola

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An F-104, with the tail arrangement of X-15 (Flat back of X-15 vertical tail unit is to reduce Base Drag at hypersonic speed), avoiding the Super-Stall danger of 'T' tail unit, looks fine. Who will buy this idea? Blessings +
 
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Urquiola

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Early in aviation, most was wood and fabric made, then came all-metal; later in past century, the composites.
Well, you know concrete is a composite, besides sand, iron bars or nets, you can add lots of different things for a reinforced, prestressed concrete, just some testing is needed.

The Tech School in Karlsruhe, Germany, managed to build a Kart sized car in concrete, with walls as thin as 4 mm, thus opening the possibility of a re-entry or space vehicle made in concrete, which has a high heat resistance, evidenced in the Madrid Windsor building fire. Heat pipes are very good in getting rid of heat.
In shipbuilding, it was shown that BV-246.jpgBV-246 Concrete Wing.jpgBV-246 Wing at Smithsonian.jpgfrom a hull lenght above 10 m, the ratio hull weight to buoyancy in a concrete boat is same or better as with a traditional wood or steel hull.
Structures in the F-104 and NASA lifting bodies don't look extremely complex, not beyond a homebuilder's abilities
You can have also look at UK document CP 1076, in Cranfield Repository, added here in Homebuilt airplanes by Barnaby Wainfan, designer of facetmobile, about an Ogival leading edge Delta wing planform, working better without the wingtip vertical surfaces, not winglets, and having a vertical central fin instead.
You may know that Blohm und Voss produced in the 40s some Gliding bombs with wings made of concrete, the BV-246. Patent US2776100 is about a procedure to make wings in concrete.
 

Doggzilla

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Most thin concrete is reinforced with fibers. I know the concrete boats sure are, I used to race them.
 

trimtab

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I think this pretty much confirms the retirement and second careers of FAA leadership inside Boeing.

And lets Boeing sell an airliner I won't fly on.

 

Victor Bravo

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I may or may not have posted this before, and it may or may not have been brought up by others in this thread. I didn't read all 37 pages. My apologies if this is old news.

An airline transport aircraft components engineer I know, who has spoken at length with people close to this situation, explained one of the root causes of this issue. For ground clearance and FOD ingress reasons, the significantly larger diameter engine on the MAX had to be moved upward towards the bottom of the wing, to the point of causing significant aerodynamic interference at certain AoA. If you notice in the pictures, the engine pylon is a lot smaller, and the top of the engine cowl is a lot closer to the wing than ever before.

So it's my understanding that this is the major "big picture" problem that can't just be fixed with software, disconnecting an autopilot feature, etc. etc. Boeing could re-do software and get the airplanes back in the air within a much shorter time if the problem was simply software. But an engine cowl creating a stalled section of wing, or interfering with the spanwise lift distribution, is not something that a software jockey can fix.
 
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Niels

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Professor Jan Roskam tells that Boing made three competing teams for initial layout of the new small,intercity jet for Lufthansa, that became 737.
One design had engines on pods below swept wings like a B47(based on best german WW2 brainwork)
One had engines aft like the french Caravelle
and the third had engines on pylons over the wings as on VFW 614

The VFW 614 configuration was best,but the damned Lufthansa people said no as passengers should not look at engines.

The VFW 614 layout would, if built, have kept Boing out of the mess they are in now, according to VB.

What about suing Lufthansa for a significant bigger amount of money than VW had to dish out?

It is all the faults of those damned germans?
 

ScaleBirdsScott

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Nothing to do with Lufthansa or any other customer far as I can tell. It's up to the aircraft mfg to make it safe at the end of the day. If they had to push things to meet customer demands they still have to make it work.

IF the design is changed much later on, it's on whoever changed it outside of the good parameters. So unless Lufthansa specifically was responsible for forcing Boeing to go to the new configuration with the understanding that doing so would be bypassing safety rules by cheating, then it's still not on them, and not like the VW situation.
 

aeromomentum

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A fellow engineer friend that formerly worked for Boeing said that engineering proposed an all new design but this was rejected by management. Then they proposed a major modification to the fuselage and wing to allow a longer landing gear but this was also rejected by management. Then they proposed a telescoping landing gear but again this was rejected by management. When management decided to put the engines higher and more forward and add on a software band-aid, he quit.
 

Victor Bravo

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Suing Lufthansa makes no sense. The 737 was in progress long before then, illustrated by the fact that Boeing has used essentially the same fuselage on many of its airplanes since the original 707.

Even if Lufthansa (or Delta, or Aeroflot, or Ryanair) insisted on a design feature that didn't make sense or was not safe... Boeing's engineering team and corporate management has a responsibility to not build it in an unsafe manner.

Even in the modern jet era, Boeing has a long and storied history of design innovation and safety, going back to the reinforcement straps around the fuselage to stop crack propagation.

Corporate America also has a long and storied history of allowing things to happen that are not right, in the name of the shareholders and the P&L statement.

The idea of the engineers proposing a telescoping gear, or a new structural design to allow the larger engine to stay out of the wing airflow... that sounds like engineers trying to do the right thing.

So I am absolutely convinced that the real engineers at Boeing... the ones with pocket protectors and nerdy glasses... are NOT responsible for the safety problem.

We are fortunate here on HBA to have many veterans of Corporate America, even in the aerospace engineering sector. Perhaps one or two of those members can comment on how engineering and corporate management interact when it comes to major safety issues?

(sound of me running and diving behind a dumpster to avoid gunshots)
 

TFF

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The original series had 50 crashes. A lot of this is tolerance. Belief in perfect out of the gate. Man made things are not perfect. There are always flaws. They are always found. This is not the last manufacturing problem for the industry, check back in 30 years.

This High profile mess that has to be seen to the end, but I bet a Max will never fly a passenger again. I see cheap new cargo planes. FedEx, UPS, Amazon are waiting for a fire sale. Boeing’s real problem is what to fill the space with. Owed customers can’t decide if they want what was promised, something different, or nothing because of current passenger levels.

The max today is like a forest fire next to the coast. You got fire fighters fighting the fire but a title wave is coming that is going to put out the fire. The old problems have nothing on the new coming problem.
 

BJC

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comment on how engineering and corporate management interact when it comes to major safety issues?
I’ve been in that predicament many times. It is simple; it is the design engineer and the design approving authority who have the final say. That does not mean that they could overspend the budget by invoking “safety”.

I’ve also interacted with senior management on other (non-engineering) issues. Example: what to do with a billion + dollar electric generating station when a Category 5 hurricane is approaching, recognizing that it could take more than a day and a half to get it shut down to the point where employees can evacuate to a safe location without damage to the plant? Senior corporate management insisted that they would make the call; I told them that I would. They said that I wasn’t allowed to. I said that I am on site, and they don’t have any way of stopping me.


BJC
 

Vigilant1

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The original series had 50 crashes.
"50 crashes" isn't very meaningful unless we know the rate (how many flights) and how it compares to other aircraft of the time. Luckily, such data is easy to get.
This list is sorted by year of introduction for each aircraft series:

1597177608744.png


The 737-100 and -200 had a total of 53 "hull-loss with fatality" accidents. The rate of these losses was just 0.91 per million departures. If we look at its contemporaries (which I'll arbitrarily say are the three types before and after it), the average rate of those planes is 1.20. So, by this measure, the first 737s were about 25% safer than its peer group. Laudable, I'd think. Safest plane of this group by this measure? Another Boeing plane, the 727.

How about later 737s? The Boeing 737 series 600-900 have a commendable safety record. If we look at all hull losses (with and without fatalities) of planes with a substantial service history (at least 1 million departures), there's NO Airbus plane of any type with a lower hull loss rate. Many planes have three or more times the hull loss rate of these 737s.

The Max will get back in the air and will give good service.
ETA: Want to make commercial flying safer? Let's look at where the accidents are happening. Check the regional numbers from 2013 through 2017. There are lots of reasons for the disparities. But nobody should believe that the maintenance standards of all airlines are the same, or that all crews worldwide meet the same standards.
1597179941300.png
 

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trimtab

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The Max presently enjoys roughly a 10x higher chance of killing people by virtue of its management team and corporate culture.

If it was merely an engineering issue, I'd feel better about riding them.

The issues with the aircraft could never get by in a new airworthiness process. They are a rationalization of failure.

But who cares...

It is still safer to fly to other continents than to spend weeks driving and boating there. But nothing says I need to travel at all for work in the age of covid- the world has changed. Airlines will have to change, and that means new planes, routes, less hub and spoke, and other arrangements. It's less attractive. It will be stunningly more expensive.

I'll spend the 2x the money and time to put 100ll in my own and avoid the petri dishes that are airports and airliners when I need to travel. If the spam can cattle cars can't survive without the Max, it isn't likely they could have with the max, and maybe it will put a damper on the present pandemic.
 

BJC

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The Max presently enjoys roughly a 10x higher chance of killing people by virtue of its management team and corporate culture.
Please share the determinant factors and the supporting math used to justify “roughly 10x higher chance”.

How do you differentiate the chance based on flight crew, as opposed to the aircraft?

Thanks.


BJC
 

Starflight

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I am in agreement with VB, and I am an ex-Boeing assembly tech from the Winnipeg , Canada plant. The 800MAX is a "rat rod" project that got out of hand. The main fault being the refusal to re-design the center section with slightly extended span to accommodate the required longer under carriage. The new design could have used all the wing-to-body-fairing panels and ECS doors. Then deeper engine pylons could maintain ground clearance and proper thrust generated trim. With an extra 4 feet of span, the aircraft would probably fly better as well. Just think of the number of recalled employees that modification process could provide jobs for!
 

trimtab

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Please share the determinant factors and the supporting math used to justify “roughly 10x higher chance”.

How do you differentiate the chance based on flight crew, as opposed to the aircraft?

Just over 10x worse than the fleet as a whole.

Differentiation is meaningless except for finding a solution. A crew and equipment combination that kills 10x more people is still a flight system that kills 10x more people.

If training can help the situation, great. But depending on less common and more heroic habits and skills to allow the crew and passengers to survive, and simply recognizing training people as critical when they refused to broach new crew training previously for business reasons (which contributed to the deaths of hundreds of humans and led to the aircraft being 10x more dangerous than airlines in general), is a culture of failed judgment that will produce more of the same.
 

Vigilant1

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The Max presently enjoys roughly a 10x higher chance of killing people ...
The 737 Max "presently enjoys" roughly a zero chance of killing passengers because it isn't in commercial service. When it returns it will be after a complete revision of the single system on the plane (MCAS) that everyone agrees is at the root of the problem, as well as training to address the clear deficiencies in the actions of some crews flying this type. This isn't an unfixable problem (wings falling off, etc), it is a relatively straightforward one.
Yes, the problem has highlighted problems at Boeing and at the FAA. Good!
 
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