It's hard because ADs don't have a brief line of text that you can clip out (following HN guidelines) yet you don't want to have title that's multiple lines long. The title does indicate that it's not all planes ("Some") but fails on the bigger issue that it's a pretty limited set of airport runways.
From a software perspective (I spent a lot of time writing software for CAD systems and CNC equipment), the combination of certain latitude/longitude values and 270 degrees (which is Pi in Radians) sounds like a classic divide-by-zero problem.
We had a potentially less dangerous issue with a CAD system that could show the tool path of the generated CNC. The CAD system shared the path formulas with the CNC equipment and for a certain "design", the CAD system showed the tool immediately jumping to a location about two inches away. This had never been observed on the CNC equipment after years of operation. We loaded the same CNC into the milling machine without a tool or work piece and sure enough, the same instruction/coordinate combination caused the mill to jump those two inches at its maximum feed-rate. Needless to say, finding and fixing this bug became our top priority!
The PDF has a four sentence summary. The lazy critic did not quite reach the second sentence, which literally prohibits a selection of planes from landing on some airstrips due to a dangerous software bug (the details of the bug, which airstrips, and sort of why, is in the rest of the article — but it's pretty clear the lazy critic didn't make it past the post here).
If they'd read the whole PDF, they might have seen these bits:
"All six display units (DUs) blanked with a selected instrument approach to a runway with a 270-degree true heading, and all six DUs stayed blank until a different runway was selected."
And:
"An unsafe condition exists that requires the immediate adoption of this AD without providing an opportunity for public comments prior to adoption."
That's pretty serious, and indeed fits exactly with "some Boeing 737s can't land due West."
smoyer|4 years ago
From a software perspective (I spent a lot of time writing software for CAD systems and CNC equipment), the combination of certain latitude/longitude values and 270 degrees (which is Pi in Radians) sounds like a classic divide-by-zero problem.
We had a potentially less dangerous issue with a CAD system that could show the tool path of the generated CNC. The CAD system shared the path formulas with the CNC equipment and for a certain "design", the CAD system showed the tool immediately jumping to a location about two inches away. This had never been observed on the CNC equipment after years of operation. We loaded the same CNC into the milling machine without a tool or work piece and sure enough, the same instruction/coordinate combination caused the mill to jump those two inches at its maximum feed-rate. Needless to say, finding and fixing this bug became our top priority!
civilized|4 years ago
This seems like lazy, half-baked criticism.
NikolaeVarius|4 years ago
How about "Some Boeing 737's cant land on some runways due to programming issue"
The current title is literally incorrect, they can all land due west just fine except for some particular runways
__te__|4 years ago
If they'd read the whole PDF, they might have seen these bits:
"All six display units (DUs) blanked with a selected instrument approach to a runway with a 270-degree true heading, and all six DUs stayed blank until a different runway was selected."
And:
"An unsafe condition exists that requires the immediate adoption of this AD without providing an opportunity for public comments prior to adoption."
That's pretty serious, and indeed fits exactly with "some Boeing 737s can't land due West."