Originally Posted by
readywhenyouare
You are right that the microburst was undetectable. But they should have known enough not to fly through a thunderstorm. Perhaps read the NTSB report.
Perhaps you should read the NTSB report. Not the summary which briefly describes the "what", but the full report that goes into "why" the "what" happened.
Summertime convective activity in the mid/southeast USA has always been considered as volatile and unpredictable. Yet this specific storm defied all expectations of how fast a storm could develop, then collapse on its own weight.
Even on final approach, DFW still considered the airport to be VFR (visual flight rules). In layman's terms, pilots will find and fly to/land on the runway by looking out the window vs using instrument/radio beams to guide them down. To be issued a "visual approach" the pilots must be able to see the runway and the plane they're following. When DFW pointed out the Lear Jet ahead of DL191, the pilot's response was something along the lines of "unable, getting our wings washed". DFW was unaware of the rain on approach. Every indication given to the pilots was that this was a simple summertime shower. It wasn't until the First Officer noted lightning that they knew they were near (underneath) something more serious.
I haven't even begun to touch on all the factors involved.
For what it's worth, this crew spent the last 20 minutes or so of their life dodging small showers that were starting to develop around DFW. They did not later end their life by
knowingly flying underneath a major convective thunderstorm.