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Comment by Scoundreller | Hacker News Reader

> All planes that don't have it already will get the "AoA Disagree" detection

It makes me wonder... if all planes had 2 Angle of Attack sensors, why was the disagree indication an extra option?

Was it almost pure price discrimination on the part of Boeing? A $4 light/buzzer for equipment, wiring and firmware already present, but only wired in for clients willing to pay an extra $10k per plane for the safe version?

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Was it almost pure price discrimination on the part of Boeing?

Probably.

A $4 light/buzzer for equipment, wiring and firmware already present, but only wired in for clients willing to pay an extra $10k per plane for the safe version?

Nope, EICAS literally a warning message which is just text on the LCD.

> Was it almost pure price discrimination on the part of Boeing?

In at least one other case I vaguely recall, monitoring two sensors required bus bandwidth that was unavailable without a physical refit of cabling or electronics, so that could well have been the issue with AOA sensors and MCAS. I have no knowledge either way.

I imagine after the design of the 737 Max was completed, some customers requested that feature, and Boeing said "For just $100k extra, we'll design and build it for you". They then set an engineer to build and test the feature, probably costing nearly $100k. That airline then got the feature they'd paid extra for, and other airlines/groups of airlines didn't get it because it isn't officially part of the design.

Any proof for this interesting theory?

I imagine not.

That is indeed exactly what the nytimes article suggested

I guess this article? https://www.nytimes.com/2019/03/21/business/boeing-safety-fe...

But my question was more like this: If it cost, say, $10k to buy the option, how much did it cost Boeing to actually enable it? If it was $8k, ok, but if it was $8 or $80, then they're more culpable.

I worked for a company making small electronic devices with LCD screens. There were two models of the device, a cheap one with a smaller screen and an expensive one with a bigger screen.

After a careful look it turned out it was cheaper for the company to put a bigger screen in both models, but as a plastic cover on top to make it look small.

It didn't compromise the safety though.

I remember CD burners were like this. You could turn a 2x burner into a 4x with a firmware upgrade.

Overclocking brings up similar circumstances: The market may have been 50/50 for the low-speed and the high-speed versions of a chip, but the yield may have been 70, 80 or even 100% for the high-speed, but the manufacturers still wanted to create a low-end and a high-end market.

Overclocking brings up another example - a lot of AMD CPUs have extra cores that can be unlocked. They're manufactured as the higher-end chips, then just have cores disabled. Sometimes due to defects, but often they work just fine.

I recall some video card where you could change a resistor and fool the card into realizing all of the extra capacity it was built with and had available.

Much of that is related to binning rather than price gouging - https://www.tomshardware.com/reviews/glossary-binning-defini...

If that was 100% true, then Intel wouldn’t multiplier lock its chips.

TIL: binning

The Sennheiser HD 595 headphones from several years ago were exactly the same as the HD 555's except for being $150 more expensive and missing a piece of adhesive backed foam stuck to the inside of the ear cups behind the drivers that were put there to give the cheaper pair a worse frequency response.

Back in the late 80s, we ordered a $100.000 upgrade for a minicomputer system. The technician literally used a pair of pliers to cut a wire on the board, and the upgrade was complete.

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