Brah wrote:Re the post just before this one, I don't know the first thing about commercial aircraft flight, but have been on a number of flights where we were 'rushing', and it always scares then hell out of me.
It feels more like free-fall than tailwind, that the plane is pointed slight towards the ground and rushing at it, feeling barely in control.
Nothing to be scared about, actually. Unlike takeoff, where your rate of ascent is determined by the aircraft's maximum climb out rate (around 3000 feet per minute for your average airliner), descent rates are determined by flight patterns, proximity to urban areas and noise restrictions, and weather.
There are three ways to force and airplane to descend. For a normal descent, and although you don't notice it, the nose is pointed down, and the plane flies down to a landing. The rate of descent is related to cruise speed. Faster descents result in higher speeds.
For a quick descent, the spoilers are deployed and lift of the aircraft is drastically reduced. This is also done in a nose down configuration, only it may be more noticeable to the passengers, especially since the spoilers make a lot more noise. This is probably the "rushing" to which you refer. Spoilers allow the aircraft to get down faster without increasing airspeed. Rest assured it is completely controlled flight, just that with reduced lift, the plane can drop at 5 to 6 thousand feet per minute (the maximum rate being determined by the rate at which the cabin pressurization system can keep up. This type of landing happens when there are minimum height restrictions... like flying into Jackson Hole, where you have no choice but to drop in over the mountains, staying above storm cells until the last minute, or noise restrictions where planes must stay at a certain height over urban areas.
And finally, there is the emergency descent. The aircraft has a steep nose down angle, and flies at the maximum speed the aircraft can manage... around Mach .83. It is possible to achieve descent rates to 10 to 12 thousand feet per minute, and I reckon everyone will be nervous about this maneuver.