To me, more dangerous, is that some safety systems are considered optional. Surely the plane either needs a safety feature or not, and it shouldn't be down to someone at an airline to make a decision on?
There is usually no such thing as "safe" or "not safe". It's more like "X% chance to happen". X might be really, really small, but not zero. Usually you can make X arbitrarily small, but the amount of money needed grows non-linearly. Do you pay 10x the price of an aircraft to reduce the chances a problem so that it goes from happening once every 100 years to once every 1000 years?
Who should make the decision whether an airplane is "safe enough"? Should it be the buyer who wants the safest plane? If you did that then rich airlines could keep out new competition by specifying safety features that make airplanes more expensive than they need to be. Should it be the country where the airline is based? But different airlines are based in different countries. Should there be options so that one country can specify higher standards than others?
Basically, that's how you get where we are I think. I'm not sure how you avoid that.
it's worth pointing out, however, that it was a software-only feature that they turned on or off depending on whether the customer had paid. If I understand right?
I think that changes the calculus of "Do you pay 10x the price of an aircraft to reduce the chances a problem so that it goes from happening once every 100 years to once every 1000 years"
They had already invested the money to develop the feature. Delivering a plane with or without it to a customer had the same cost. If the customer paid more, they got the safety feature turned on, the end.
> Delivering a plane with or without it to a customer had the same cost
Not exactly, surely. The ongoing/recurring costs to Boeing would be increased with the feature enabled - it's another thing that can go wrong and must be monitored, it changes support requirements and the overall software runtime complexity. I assume that would get factored in, somehow...
Different countries have different standards of safety, and different budgets. Boeing got more $$$ from airlines in the US by making planes in Ethiopia and Indonesia less safe. Yay capitalism.
That’s weird to say. Lion Air is a sloppy, cheapskate airline — look at their horrible maintenance and crash history for evidence of that. That they didn’t want to pay slightly extra for additional options on the plane was their choice. And Ethiopian is a flag carrier: they could have easily gotten the extra option, but likely some accountant thought it wasn’t necessary. Who spends over $100 million on an airplane and then declines a $1 million safety option?
Someone who wants to buy 100 of those airplanes, but knows that the safety option reduces the risk of incurring a $100 million total hull loss by less than one percent, thus saving less than the $100 million extra cost for the option? Obviously the numbers are different, but see the oft-quoted 'Fight Club' line about product recalls for similar logic.
Southwest didn't buy the option either until after the Lion Air crash:
In manuals that Boeing gave to Southwest Airlines — the biggest operator of both the MAX and 737s in general — the warning light was depicted as a standard feature just as it is on older 737s, according to Southwest spokeswoman Brandy King.
After the Lion Air crash, Ms King said, Boeing notified Southwest that it had discovered the lights did not work without the optional angle-of-attack indicators, so Southwest began adding the optional feature too.
I agree, but was responding to a post that was heavily criticising Lion Air for not paying for the option and implicitly laying the blame for the crash at their door. Either the option was safety critical, in which case Boeing had no business making it optional, or it wasn’t, in which case blaming Lion Air is unreasonable.
Given that thanks to Boeing, the Lion Air crew didn’t even know the MCAS subsystem existed, and that MCAS would continue to rely on the single faulty sensor however many extra redundancies were installed, the decision not to buy seems kind of irrelevant.
> Either the option was safety critical, in which case Boeing had no business making it optional
This is the part I was trying to clarify. I don't know Boeing's internal processes, but there certainly could be options that are safety-critical but still optional because they are ranked low enough on the severity/probability/detectability scale.
I agree that it's wrong to blame Lion Air as the consumer. The fault seems to be in Boeing misapplying the risk categorization.
It's not a random assumption. I read in some recent article that the airlines in the US have the feature--sorry I don't remember which, but you can look it up as easily as I.
You're the one who made the factual statement. I'm not the one that's obliged to back that up.
Wikipedia lists the customers, and the number of aircraft delivered to US airlines is a good match for the 20% of aircraft that are said to have that feature. However, that assumption implies that 0% of leasing companies ordered it, that 0% of Canadian customers did, that the American airlines bought all their aircraft and didn't lease any, etc. Might all be true but you can see why I asked for a citation.
I mean less safe relative to shipping the same hardware with the warning feature enabled, which they could have done at no cost except the loss of loss of price discrimination (which I'm sure was substantial, but probably not enough that they don't now regret it)
Since the 737 MAX also has military customers, it may be more likely that Boeing's design of the modular components was compromised by the need to accommodate military specs, which often leave off 'unnecessary consumer safety options' ..
It has to do with the classification during the system safety analysis (SSA). IIRC, the MCAS was classified as 'hazardous' if failed but not 'catastrophic'. If it were classified as a higher hazard level, it presumably would levy additional requirements. It's a risk-based approach, which sounds like they failed to appropriately classify the risk.
Last time I bought a new car, this was actually a pretty important factor for me -- one car was nominally cheaper, but had a number of optional safety features (like rear passenger pillar airbags, IIRC), and they brought the price to parity with the other car I was considering. I figured I'd hate myself if I declined to buy some optional safety features and ended up with an injured passenger as a result, so ended up including all of them in the purchase price, and eventually went with the higher-base-price car.
The really sociopathic part is the upselling of it as a separate feature when the actual marginal costs are nill. It is one thing if they have to retrofit it but the 737 is newer - just doing it the most expensive option seems like it should give the most logistical savings and be the best for long term profit. I mean people look at the safety record and a crash makes them look bad even if it was pilot error.
It's a tool. Without the warning you can add up the approximate weight of passengers and luggage, and check it's below the maximum. I'd like to think this is done as a matter of course.
I'm not sure what you're responding to, but AoA indicators have very little to do with weight and balance.
Fuel loads, critical airspeeds, and maneuvering characteristics are indeed governed by weight and balance. That has nothing to do with AoA reading mismatch indicators.
Was there a separate question about automatic weight and balance measurement as a feature?
Actually, when I bought my last car, I did get the trim level that had all the extra safety features.
However, I'm not transporting passengers for money and accepting liability for passengers' lives; airlines do, so their financial calculation should be very different from Joe Blow private car buyer.
Finally, if I understand correctly, these extra safety features were software only, meaning they don't cost the manufacturer anything to add on, so there's no excuse to not make them standard. On cars, the extra safety features require expensive sensors, so they really do add to the BOM cost of the car, and putting them on an economy car really could push the price too high for buyers to afford, so carmakers put them in higher-cost models to help make them more commonplace and then move them into lower-cost models as the volumes increase and economies of scale make costs lower.
To me, more dangerous, is that some safety systems are considered optional. Surely the plane either needs a safety feature or not, and it shouldn't be down to someone at an airline to make a decision on?