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Originally posted by Evan
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Changes in vertical and lateral speed can be deceiving and disorienting (even for pilots). This is due to weaknesses in the human vestibular system, which didn't evolve with flight in mind. You almost certainly experienced a drop in altitude and speed but not in pitch, perhaps due to clear air turbulence. The thing to look at on your graph is airspeed. If the plane had gone into a dive, the speed would significantly increase as the altitude decreased. But both are decreasing on the graph. This means the plane is descending due to a speed reduction, not a pitch reduction. Delta seems to be telling you the truth and such events are impossible to prevent.
But the important thing is the quick response of the crew to keep things stabilized. You arrived safe and sound because Delta pilots are very well trained. This discussion about accident rates is nonsense. What matters is safety culture and Delta has a very good one (thus far).
But I love that she put you on hold. She must have called the pilot at home to ask him what happened
But the important thing is the quick response of the crew to keep things stabilized. You arrived safe and sound because Delta pilots are very well trained. This discussion about accident rates is nonsense. What matters is safety culture and Delta has a very good one (thus far).
But I love that she put you on hold. She must have called the pilot at home to ask him what happened
What I see is a very steady descent from 35000 ft to say 17000 ft, with the speed remaining essentially constant until almost the level off, then the plane levels off at 17000 ft and slows down to about 270 kts. Note that the speed show is probably groundspeed, ot at leas true airspeed. It cannot be indicated airspeed because plane don't fly at 500 kts indicated. So at 17000 ft, the 270 kts is likely slightly below 250 kts indicated. Note that Salt Lake City (the destination airport) has an elevation of 4200ft, so it looks like they leveled off at 17000 and then slowed down below 250 kts indicated which is the speed restriction below 10000 ft AGL (that would be about 15000 ft there), to be within the speed limit when the continue the descent.
The descent from 35000 ft to 17000 ft (that is a loss of 18000 ft) took about 5 minutes, which gives you an average of 3600 fpm. That's not unusual. Many times due to traffic restrictions/conflicts ATC either keeps you up more than you would want, or wants you down below certain altitude sooner than you would like. That is why it is quite frequent that pilots use air brakes during the descent: to be able to descend quicker (at a faster vertical speed) without the speed increasing.
In other words, I would say "nothing to see here".
Where in the graph do you see a hint of the drop in altitude and speed due to clear air turbulence?
Ladylovleylegs, How many times did you fly before this Delta Airlines Disaster flight?
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