They didn't get a terrian warning because they were landing. Being close to the ground is what they expected. They have both radar & pressure altimeters.
What might have happened is that due to the poor weather they thought they were closer to the airport, or they weren't closely following their glide path, or the aircraft was misconfigured for the RNAV approach. Perhaps a combination of the three.
If they are too low according to TAWS map, there would be warning even if they were landing. You can inhibit some of the alerts by switching TAWS into "Terrain Inhibit" mode, but that's usually done for landing at runways outside of TAWS database.
That said, TAWS won't fire if you're below airspace-mandated altitude but above "minimally safe" altitude.
It is not that big a deal. It is in fact a lot easier than mining deeper geothermal which we can also do, but at much greater expense. Yellowstone aside, exploitation of resources is one thing America is profoundly good at. If we start now, we can finish it in say one thousand years and fully eliminate the supervolcano risk, also enjoying much green energy in the process.
Oh, you're right, I spaced. I've been away from Google for a few years now, and I remembered the titles and Lx being off from each other but had it mixed up. Thanks for speaking up; I was wondering what the deal was with the downvotes.
When you take off, you're going up at a rate of 500 fpm to 2000 fpm. Even if you go from +1000 fpm to -1000 fpm over the course of several seconds, you aren't going to feel much.
At cruise altitude, you're moving along at 500 mph, which is 777 feet per second. So going from +30 feet to -30 feet in a minute is just an adjustment of only about 5 degrees. You'd barely feel it, even walking down the isle. An acceleration of 33 ft/sec per sec is 1 g.
You experience greater changes in vertical motion on any flight you go on.
> So going from +30 feet to -30 feet in a minute is just an adjustment of only about 5 degrees. You'd barely feel it, even walking down the isle.
You would pretty obviously feel a change in pitch of 5° walking down the aisle.
You mixed feet per second and feet per minute. 60 feet of change across 777 feet of run is about 4.5° (inverse sin(60/777)), such as you'd experience if the change was in 1 second instead of in 1 minute.
Calculating 60' change in 777*60 feet, inverse sin (60/(777*60)) is 0.07°, which is why you don't feel that change in inclination of the aisle.
Almost all aircraft are equipped with ADS-B transponders, which transmit their tail number and location continuously. Anybody can buy a ADS-B receiver and see info for aircraft flying near them.
In good internet fashion, people figured out that they can coordinate large networks of receivers, which basically centralizes a nationwide database of all aircraft movement.
So, all this account did was tweet when Elon's jet moved from this central ADS-B database.
I can't help but think this is the only sensible approach.
Persistant performance related issues are management's responsibility. It's unfair to withhold their vesting mere weeks from their vest date when management should've addressed the issue earlier.
What might have happened is that due to the poor weather they thought they were closer to the airport, or they weren't closely following their glide path, or the aircraft was misconfigured for the RNAV approach. Perhaps a combination of the three.