E.U.’s Biggest Economies Ban Boeing Max 8 Jets • Hacker News Board

Re: E.U.’s Biggest Economies Ban Boeing Max 8 Jets

#311

Post by rocqua » Tue, Mar 12, 2019, 9:07 PM UTC

Someone1234 wrote: post #157

sfilargi wrote: post #146

I urge people to read the discussion by pilots regarding the 737 MAX. https://www.airlinepilotforums.com/safety/120514-ethiopian-7... It all comes down to this: "There are far too many aerodynamic bandaids that are permitted to pass the current standards. Not just this particular airplane, but a whole bunch of airframes. If the basic aerodynamics won't pass without the pushers, pullers and now AOA induced changes to…

Pilots have been pushing back hard on the narrative that this was simply pilot error. The crux is that safety agencies never mandated training on these new systems, and new procedures weren't created with them in mind. Worse still procedures from older models of the same aircraft (such as automatic overriding of auto-trim) were removed without re-training on that either. Lion Air had to repair the AOA sensor multiple…

I recall reading on HN that a second AOA sensor was an option.

Re: E.U.’s Biggest Economies Ban Boeing Max 8 Jets

#312

Post by zaroth » Tue, Mar 12, 2019, 9:09 PM UTC

AWildC182 wrote: post #284

edoloughlin wrote: post #279

Earlier quoted context omitted.

such airframes induce more drag and burn more fuel As a curious bystander, I assumed using fly by wire tech to achieve stability would involve using control surfaces, which increase drag by their nature. How would an airframe that's naturally stable and doesn't require control inputs burn more fuel?

It's more about preventing a stall with a swept wing which is needed to achieve high mach numbers. That said, an easy (but different) case to visualize is a traditional tailplane. The center of gravity on an airplane is in front of the wing so it wants to pitch down slowly. The tail pushes DOWN in the back to keep the nose up. Nose heavy planes are stable and forgiving but you induce drag because the wing needs to su…

That’s a great explanation, even if it is oversimplifying.

We don’t build planes with training wheels anymore because the performance cost was too high. Planes are still the safest way to travel even without the training wheels.

I don’t think 737 MAX 8 pushes the envelope too far. I think they screwed up on re-training the disengage, and they may have screwed up on redundancy by only using a single AoA sensor, but I also am guessing the latest crash has absolutely nothing to do with trim.

Re: E.U.’s Biggest Economies Ban Boeing Max 8 Jets

#313

Post by Scoundreller » Tue, Mar 12, 2019, 9:09 PM UTC

riazrizvi wrote: post #257

anoncoward111 wrote: post #119

Earlier quoted context omitted.

Two crashes in 6 months and there's only 350 planes in existence is a pretty bad safety record that is probably on par with Tupolev. The US can tacitly blame "third world" pilots all they want, but with 300 people dead already, I think it's important for the FAA and Boeing to say exactly what is going on, especially since the planes are in use in the USA. There is a debate over if the plane's hardware, software, or p…

The Boeing Max 8 entered service in May 2017. Assuming a linear deployment rate, the 350 planes in service have seen an average life of 10 months. Assume 4 flights/day, that's 420,000 flights so far. 2 have gone down. A best estimate of the likelihood that a plane goes down (MLE), p = X/n = 2/420,000 = 1/210,000 ~ Binomial(n=420,000, p=P(crash)). According to the Economist [1] the likelihood your plane goes down gene…

If I have an upcoming flight on a MAX 8, can I sufficiently compensate for any increased risk by taking the train to the airport instead of a 25km Uber drive?

Re: E.U.’s Biggest Economies Ban Boeing Max 8 Jets

#314

Post by [deleted] » Tue, Mar 12, 2019, 9:12 PM UTC

notfromhere wrote: post #19

foepys wrote: post #13

Earlier quoted context omitted.

Didn't Boeing also market the plane as an evolution of the 737 that doesn't require retraining? So pilots with experience on the 737 can automatically fly the 737 Max?

Yep, that was the big selling point since airlines hate retraining pilots. Totally backfired in that regard though.

[deleted]

Re: E.U.’s Biggest Economies Ban Boeing Max 8 Jets

#315

Post by theoh » Tue, Mar 12, 2019, 9:12 PM UTC

erokar wrote: post #291

pasta wrote: post #285

Earlier quoted context omitted.

Trump tweeted that planes have become too complicated and that the old and simple form is much better. His tweet sounds dumb but there is some truth in it. As you say, planes and procedures have become very complicated. And I think there are only two options: making planes simple again which make them less efficient or let computers fly the plane and make the interface simple(r). If you look at the rockets of SpaceX…

> His tweet sounds dumb but there is some truth in it. There really isn't. Automation is part of what has made flying safer over the years. Also, compare the cockpit of an Airbus with e.g. an old B737, the 300 series for instance. The Airbus cockpit is much simpler, in the sense that there are less gauges and knobs for the pilots to be concerned about. Automation has, over all, made things simpler and safer.

Citation needed, please.

The most convincing popular article I've read on this topic is https://www.vanityfair.com/news/business/2014/10/air-france-...

It's far from clear-cut that the way automation is happening is advisable, however conservative it might appear to be, and I'm sure you'd agree that there are many confounding variables that make it difficult to say just what is responsible for the trajectory of aircraft safety. There's not much of a control group of advanced modern aircraft which omit automated features.

Re: E.U.’s Biggest Economies Ban Boeing Max 8 Jets

#316

Post by [deleted] » Tue, Mar 12, 2019, 9:13 PM UTC

anoncoward111 wrote: post #119

eric_b wrote: post #109

At the gym today, on all the TVs, the media talking heads were crucifying the FAA for being "unsafe" or playing fast and loose with passenger safety (for not grounding the planes). I've always held the FAA in high regard, and think they do a good job. Are they really being negligent here? Or is the media just looking for something to spark outrage? Can anyone with more specific knowledge of aircraft safety weigh in?

Two crashes in 6 months and there's only 350 planes in existence is a pretty bad safety record that is probably on par with Tupolev. The US can tacitly blame "third world" pilots all they want, but with 300 people dead already, I think it's important for the FAA and Boeing to say exactly what is going on, especially since the planes are in use in the USA. There is a debate over if the plane's hardware, software, or p…

[deleted]

Re: E.U.’s Biggest Economies Ban Boeing Max 8 Jets

#317

Post by ehudla » Tue, Mar 12, 2019, 9:13 PM UTC

What programming language is used for the avionics?

Re: E.U.’s Biggest Economies Ban Boeing Max 8 Jets

#318

Post by dlgeek » Tue, Mar 12, 2019, 9:15 PM UTC

briandear wrote: post #282

nraynaud wrote: post #185

Earlier quoted context omitted.

You just can't have more data points, because flight travel is too safe. And no, the FAA is not really that good, general aviation pilots die all the time from negligence and the FAA doesn't enforce the rules when pilots violate them (in particular low altitude flying).

What’s the “low altitude flying” rule that isn’t being enforced?

https://www.law.cornell.edu/cfr/text/14/91.119

§ 91.119 Minimum safe altitudes: General.

Except when necessary for takeoff or landing, no person may operate an aircraft below the following altitudes:

(a)Anywhere. An altitude allowing, if a power unit fails, an emergency landing without undue hazard to persons or property on the surface.

(b)Over congested areas. Over any congested area of a city, town, or settlement, or over any open air assembly of persons, an altitude of 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet of the aircraft.

(c)Over other than congested areas. An altitude of 500 feet above the surface, except over open water or sparsely populated areas. In those cases, the aircraft may not be operated closer than 500 feet to any person, vessel, vehicle, or structure.

(d)Helicopters, powered parachutes, and weight-shift-control aircraft. If the operation is conducted without hazard to persons or property on the surface -

(1) A helicopter may be operated at less than the minimums prescribed in paragraph (b) or (c) of this section, provided each person operating the helicopter complies with any routes or altitudes specifically prescribed for helicopters by the FAA; and

(2) A powered parachute or weight-shift-control aircraft may be operated at less than the minimums prescribed in paragraph (c) of this section.

Re: E.U.’s Biggest Economies Ban Boeing Max 8 Jets

#319

Post by zrobotics » Tue, Mar 12, 2019, 9:15 PM UTC

StreamBright wrote: post #306

sandworm101 wrote: post #283

Earlier quoted context omitted.

Yes it would. There are backup systems to keep things working even with both engines dry (ram air turbine etc). In fact, if you really want to stretch our a glide, all those automated systems are probably a good things. They will keep the aircraft more perfectly trimmed for a glide than the pilots ever could by hand. https://en.wikipedia.org/wiki/Ram_air_turbine

And in case of the electrical system being down how do you control the flight when you have fly by wire controls?

If the electrical failure is severe enough to lose control authority, it seems just as likely that a hydraulic system would have failed. These planes are just too large to operate the controls mechanically, so in practice there is just as much to fail in a hydraulic system as electrical control, since both require power.

Re: E.U.’s Biggest Economies Ban Boeing Max 8 Jets

#320

Post by zaroth » Tue, Mar 12, 2019, 9:18 PM UTC

The black box has been recovered. The data is probably being recovered as we pontificate. Within the next 48-72 hours I expect someone will know definitively if the MCAS system was even active, and if trim was a factor in this crash.

Given that this significant data point is hours or just a couple days away, isn’t it prudent to get the data before grounding the fleet?

If the jet had been brought down intentionally, should the FAA have grounded the aircraft? Crashes like this are so incredibly rare, and on a new aircraft perhaps the easy decision is to just ground it. But shouldn’t that require actual evidence on the cause of the crash?

Witness accounts are of the plane trailing smoke and debris, but I don’t trust those at all. I feel like given that we will know definitively if trim was a factor in the crash so soon, a decision should only be made once that is known.