How do planes land so accurately?

Question

Descending through thick layers of cloud, how can the pilots see or estimate where the runway is to land so straight?

Answer 1

Kevin H. described an ILS perfectly. I will add that a normal ILS will get you down to 200 ft above the ground while a Cat II ILS will take you down to 100 ft above the ground. Not all aircraft or aircrew are qualified to do CAT II's though. And as someone earlier stated about this being a fully automated landing system, they are incorrect. That would be a CAT III(b) or (c) system, can't remember which one.

Some other instrument approached are the VOR, NDB, and Localizer approach. These are all non precision approaches so the ceiling and visibility need to be much higher. These are used when there are obstructions that would be in the way of an ILS approach.

When it is clear outside, we will use our eyes and judgement to lign up on the runway and guide ourselves down. Some runways do have red and white lights along side the approach end to tell us if we are too high or too low.

Hope this helps.

Answer 2

The navigation aids which are currently in use ensure that aircraft go from one point to the other with great accuracy and precision. The pilots can pinpoint their position accurately at any given point during their flight. Highly advanced computing systems, both on board the aircraft and on the ground, allow the pilots and the flight controllers to predict exact arrival times and plan their departures.

The above procedures are also integrated with the ground and air systems on board the aircraft to safely bring down the aircraft through inclement weather and in times of poor visibility. The instrument landing systems are numerous and the radars do a great job by monitoring the aircraft closely.

There are set rules to descend through the clouds and the pilots follow a pattern which brings them from cruise altitude to the final approach for landing. The planes are flown on instruments and not visually, while ATC/Approach Control keep in constant touch with the pilots all the time. The controllers bring the aircraft onto the final approach and in line with the designated runway. The guidance continues till the pilots have picked up the runway visually at which time the pilots continue on their own.

Answer 3

All done by sophisticated electronics.

On modern aircraft like the Boeing 777 and Airbus 330/340 the pilot is little more than a passenger. This assumes the airport has suitable ground equipment, most have.

The British invented auto-land back in the 1970's for use on the Hawker-Sidderley Trident, No longer in service and comparable to the Old Boeing 727.

Ian M

Answer 4

ILS: Instrument Landing System. It's a complicated system used to line up with the runway by a signal being transmitted to an instrument in the cockpit. There's also Localizers and GPS approaches.

Answer 5

most of the time we use the ILS (instrument landing system) approach.. the aircraft instruments receive a signal from a strategically placed ground system.. ATC will usually maneuver you around so you are close to the extended centerline of the runway, usually 10 miles out from the airport.. then its up to the pilots to use the ILS to guide them down to the runway.. initially the signal isnt very sensitive to movement or deviation as we like to call it. but as you get closer to the runway, it becomes very sensitive to movement.. picture an invisible cone with the tip at the beginning of the runway and extended along the centerline of the runway and pointed up roughly 3 degree from the ground.. when you are far away from the airport the cone is big but as you get closer to the tip of the cone, it becomes very sensitive to movement.. our instruments tell us where we are in relationship to this cone.. our goal is to be in the exact center.. check out this graphic..

www.partners-solberg.org/
images/ils_approach.jpg

youll have to put the two lines together since yahoo isnt cooperating

Answer 6

The "old way" was GCA (Ground Control Approach). Controllers on the ground give the pilots directions based on radar/transponder signals. A GCA radar tracks in both horizontal and vertical attitudes so the data is precise, AND backed up by the transponder's signals (which also provide altitude data).

There are also ILS (Instrument Landing Systems) that permit a pilot to enter the airports "code", and then follow a "beam" down to final landing approach.

VERY rarely does the aircraft itself have radar capable of performing a landing. Most A/C radar is for weather avoidance.

During the "June Gloom" (fog from hell), I used to sneak my pilots into NAS North Island in San Diego California using the radar on the SH-60B Seahawk helicopter. I could see the runway from 120 miles out, buildings from 60 miles out, and then cars once we were inside 10 miles. We'd often cross the runway threshold and still barely be able to see the runway lights.

Answer 7

Mark: have not have been given any understanding of flying an ipod, yet i will permit you comprehend that the OBS knob on an ILS approach basically delivers a sprint of the inbound direction, it would not turn the airplane, or surely even function on an ILS approach; it basically delivers authentic function whilst monitoring a VOR. additionally, whilst a human is flying it fairly is amazingly ergonomic to have it pointed interior the final direction. As for lining up, if the CDI needle is left, then you would desire to coach left some form of tiers. no count what share tiers you turn, it won't middle until the airplane is on the main suitable approach direction. Likewise with the GS needle, it fairly is finding not for nostril up or down, it fairly is finding for a decide for the flow direction. Set the OBS to the inbound direction, and fly some 30 degree intercept perspective approximately 10 miles from the runway, approximately 2500 ft above the floor. Your altimeter would be above propose sea point, so which you will ought to comprehend the airport elevation. via fact the needle centers, turn to the inbound direction. via fact the GS needle comes off the case, initiate slowing down and configuring. whilst it centers, initiate down. regulate your heading and descent value to maintain the needles everyday.

Answer 8

There are few ways for landing an airplane on runway.
1.) Visual as noprecision approach, if weather is CAVOK which means no fog or clouds and no clouds between aircraft and runway, pilot has to see RWY in every moment of approach.
2.) NDB/VOR as nonprecision approach, in NAV1 frequaency punch in VOR that is positioned at RWY and if there is another on other end of RWY punch in in NAV2, then as you approach rwy watch needles on instrument getting alligned with each other in center, when alligned you're ligned up with RWY.
3.) ILS precision approach, there are several ILS categories but principal is the same. In NAV1 and 2 punch in the ILS freq. for RWY you are landing on, in HDG punch in true heading of RWY, activate APP button on MCP and plane will follow glide path to RWY perfeclty untill you take controls few hundred meters before RWY to land manually. You have to follow procedure for arriving airport such as STAR and intercept ILS on prescribed altitude as in chart.
And there is always expirianced pilots who can land perfectly using one of those three.

Answer 9

It is amazing isn't it. Even after almost forty years I am still fascinated every time we fly thirteen and a half hours from Oakland to Brisbane, Australia and hit the runway within a few feet of where we planned. Don'tcha just love it. I sure do.

Answer 10

Al_sheda is pretty much the best answer here. Not that it's the best explanation there is.

Although he did not include the fact that Category II commercial aircraft actually approach, flare, touch down and brake all by computer (auto pilot). The pilots just monitor and are there for safety.