aircraft landing

Planes can't see on their own. Pilots can't see very well in fog and heavy rain. Passenger planes have a very large mass component and are sluggish to respond to corrective inputs from the pilot. So visual or other instrumentation has to be dead reliable to accurately locate the plane in three space. However, atmospheric conditions are often invisible, e.g. wind shear or turbulence. Both of which require extreme remedial action by the pilot to maintain proper course and attitude. Either of the two examples encountered at low altitude will put the plane on the ground. In most non mechanical/non structural failure crashes there simply isn't enough sky left to allow the pilot to correct for the loss of lift given the time required by the machine to react positively to the corrective inputs.

hello sir. thanks for ur information. if i could get some more , i would be very grateful. i want as much informatio as possible so i can think of doing a project on it. please help thank u

Wind is always an issue, especially for smaller aircraft that land at slower speeds. If fighting a strong head wind, the wind usually drops off (and rather suddenly) as you approach the gound (due to frictional drag of the ground on the wind). All you can do at that point is to apply power to keep from smacking into the runway too hard. Usually the runway doesn't line up with the wind, so you are crabbing into the wind and maybe slipping it sideways as well (although some aircraft are not to be slipped with flaps deployed) At the last second, you need to level the aircraft and line it up so you are going straight down the runway. If you don't, what happens next is pretty hard on the landing gear and tires.

I encountered adverse flight conditions while flying helicopers often. The workload for a single pilot during IFR conditions can be overwhelming. There were times I thought I'd never make it. Stress is increased when you are dangerously low on fuel. Fuel flow meters and digital readouts are a must. Check out the NASA SATS (Small Aircraft Transportation System) program if you haven't already. The visualization for approach to landing are safer through the use of electronic glass panels and communications. You might try to catch a ride in a flight simulator to experience how hectic it can be if you have the right stuff instructor. Hope this might help in your research.

Your question is too broad.

It's true, there are so much cases.

This is the IFR condition in which the pilot will need the best of his abilities to make a safe approuch and landing.I was an airlane pilot and it takes a lot of concentration to performed under this condition,folloing stadistic 99% of this landings are safe,so,it should be not fear.

I agree. Not enough information... What kind of weather? What kind of plane? As to weather--assuming landings under Visual Flight Rules (VFR)--the basic criteria are visibility, ceiling, and ice. As to planes, I would say they problems generally devolve down to (1) not enough runway; and (2) not enough distance between plane and runway--here it is assumed that a crash ensues. One hazard that has been talked about very much--since the DFW fatal failure a couple of decades ago--is "microbursts," or sudden downdrafts, encountered during storms on approach. These have the effect of suddenly placing the plane closer to the ground, forcing the pilot to make a critical decision whether to continue the landing, or power up and go around--the latter often being necessary because the plane is too low to avoid undershooting the runway. In the DFW incident it was found that the pilot had powered up, according to correct training, and attempted to increase altitude. The latter action(while correct back then) was found to be in error because it had the effect of reducing power (in effect stalling) needed to regain altitude, making the crash inevitable. The correct pilot response, it was determined, would have been to power up, staying on the downward glide slope, to take advantage of gravity and momentum to increase thrust, before leveling and attempting to climb. Today, it is always attempted to avoid landings where microburst are possible; the advent of doppler radar at all major airports has made it feasible to do this, so this kind of catastrophe has been largely curtailed. Anyway, that's one kind of severe weather problem encountered at landings of large transports. I would recommend you search the Web for accident histories to get better ideas of recent accidents. That will get you started on finding out more about the topic you're inquiring about. Checking the FAA and the manufacturer sites (i.e., Boeing) would be a good starting point.