How do pilots determine when to descend, at what rate to descend, and how to align the plane & runway?

Question

How do they align that PLANE and RUNWAY?!!? Illustrations & Explanations

Answer 1

Unless a plane is flying under visual rules (usually not airliners - typically small private aircraft only), they follow what are called approach charts.
An approach chart details certain navigational beacons that the aircraft radios are tuned to. The DME (Distance Measuring Equipment) gives a distance from the beacon. The VOR (VHF Omni-Bearing Radio) gives a direction and there are also ADF (Automatic Direction Finder) beacons. With all of these the pilot knows pretty well where they are. (On top of that there is of course GPS, LORAN, TACAN, ....)

The approach chart tells the pilot when you are x miles from this position, turn to heading abc and descend to a specific altitude. The pilot can calculate the descent rate given their airspeed. (A nice gentleman above gave you these I think....)
As they get closer to the field, they are given more distances, headings and altitudes.
The final approach fix should have them pretty well lined up to the runway and at approximately the right altitude. This is where the ILS (Instrument Landing System) takes over and gives signals to the aircraft to tell you if you are left/right of the runway or high/low on your approach.
Many runways also have lights on the side of the runway that tell a pilot if they are too high or low. (Red if low, white if high).

After all that, it really is up to the pilot and their experience to know descent rates and alignment. It all comes down to small corrections in the end based on skill. (Unless of course they are shooting an automated landing where they don't even touch the controls until they're ready to turn off the runway! Scary!)

Answer 2

The runway heading is the heading that is aligned with the centerline of the runway used for takeoff. A "fly runway heading" instruction from ATC means stay aligned with the runway centerline after taking off. Controllers use the runway that is aligned with the wind because it is desirable to take off and land against the wind. Landing against the wind (wind direction opposite the airplane's direction) reduces ground speed along the runway, allowing for a faster takeoff or landing at a lower ground speed while the airplane's wheels are on the runway. With a 10-knot tailwind, an airplane has to roll 20 knots faster along the runway during takeoff and landing as compared with a 10-knot headwind. Controllers thus try to choose a runway that is aligned with the wind, and will assign the end of the runway that will send airplanes into the wind. There are exceptions. There was a recent incident at JFK airport during which a pilot declared an emergency just to use the runway he wanted. The controllers had assigned a runway based on traffic considerations (imposed by their supervisors), even though it had a brisk wind blowing across it. This crosswind was too high for the airliner to land safely, and the controllers wouldn't assign a more suitable runway, so the pilots declared an emergency in order to land on the runway that was more aligned with the wind. That's a problem with bad ATC procedures, though.

Answer 3

pilots will file a flight plan. a series of air traffic controllers guide aircraft through crowded airspace. this series of air traffic controllers allows the pilot to be in constant contact with an air traffic controller. the air traffic controller has a radar that allows them to see the heading and altitude of the aircraft and other aircraft in the area. also when given clearance to land on a certain runway, the number of the runway represents the heading of the runway. for example lets use runway 36R. 36 represents 360 degrees which is directly north. the "R" represents that it will be the runway on the right. also sophisticated gps navigation systems aide the pilot. one more thing. if weather and visibility is good, pilots will use their eyes along with air traffic controller to guide plane in for safe landing. pilots will also have a map to show airport layout. a lot of information i know, comes from years of playing Microsoft flight Sims. a lot of stuff in flight Sims are accurate. not all though. the aircraft these days are so technologically advanced, aligning with runway is almost effortless.

Answer 4

The point of descent is calculated by a small formula using your current flying altitude. Lets say if your flying at 40,000Ft ASL, this means you should minus the last 3 digits and end up with two numbers. In this case it would be 40. Now you have to multiply 40 by 3 which gives you 120. This gives your point of descent from 120NM miles away from the airport. This means you should start a normal descent of 1500 or 2000Ft per minute once you cross 120NM. We calculate this but then we have to request ATC for clearance prior to descent to avoid conflicting aircraft.
Aligning an aircraft is easy when you do an ILS approach as it aligns the aircraft for you but other wise you have clear instruments to align yourself. Small adjustments are made using the rudder's.
Hope this helps you.

Answer 5

The Air Traffic Control tells when to descend. Depending on the plane, its at the pilots discrepency at what rate. If it is a commerical airline or has the feature of the ILS approach and so does the runway, this system correctly lines the planes up with the runway with the added bonus of descending the planes correctly at the right rate right onto the ground.

Answer 6

there are the usual radio and direction indicators such as ILS VOR, GPS etc that a pilot uses. the ILS is what lines the plane up with the runway.I have been taught a trick that i use in Flight simulator is that for every 1000 feet of altitude you have, you should be 3 miles (i am not sure if it is nautical or statute) away from the airport.

Answer 7

I'm looking at a flight pub for Tampa Int'l, runway 27. As said above, flight parameters are laid out in these pubs.

Heading in at 274 degress, the minimum altitude should be 2000' at greater than 10nm out on approach, drops to 1600' 4.8nm out and 860 at 2.5nm.

Answer 8

They use hi tech radars and guages and GPS systems. They monitor the plans location, hight, and if its straight on an axis (not flying side ways) It has already been calculated as to wen to descent. Once the runway is in view the pilot centers the plane on the run way keeping his eyes on the Altometer (hight of the plane) his axis guage to make sure its stright and not have a wing hit. And his speed. At night time, he follows a certain color of lights to keep him straight. Its kinda like keeping a car in between the lines.

Answer 9

3 Degree Glide Slope Descent Rate Add a zero to your indicated speed, divide by two. This should keep you stabilized on the approach. Ex: 150 knots on the GS. 150(0) / 2 = 750fpm descent. 120(0) / 2 =600fpm descent, etc.

3 Degree Glide Slope To maintain a 3 degree glideslope (eg: ILS) multiply the groundspeed you are achieving by 5. The resulting number is the rate of descent to fly. Ex. Groundspeed = 110 Kts x 5 = 550fpm rate of descent to maintain 3 degree glideslope.

Double the DME for a 1000' ft per minute drop rate at 200 kts IAS. That would tell you how far out you should start the descent. Ex. I'm at FL230, cruising at 200 KIAS. I know I want to be down to what ever the IAF alt is (say 4000') before I get there, maybe 3-5 miles. Based on 1000 ft/min descent rate, if I start the descent when I am FL alt minus the alt of the IAF that gives me 19k to loose. This means if I start with 38 DME and add a fudge factor of about 6-8 then I will hit a point before the IAF at the alt I need. This is not an Exact science as under FL180 you have to change to the local alt setting. But, it does work and it usually has you down with plenty of time to spare

The distance to descend at 500 ft per minute. Equals 2 times the ground speed in miles-per-minute times the altitude to lose in thousands of feet. Ex. If ground speed in the descent is 155kts/180mph(3 miles-per-minute) and you must descend 8000ft, you must begin you descent 48 miles from the point at which you must be at the lower altitude. 2 times your 3 miles per minute ground speed equals 6 times 8 (your altitude to be lost in thousands) equals 48 miles.

Distance To Descend
Take your altitude and multiply it by 3. That equals your distance in miles to begin your descent. 2. Now take half your ground speed. This is your rate of descent in hundreds of feet. Ex. If you are flying at 12000ft at a ground speed of 150kts and you need to descend to 2000ft, the difference is 10000ft. Multiply 10*3=30 miles out you must begin your descent. Half your ground speed is 75, add a zero, and 750 ft per minute is your rate of descent.


To align with the runway, before the pilot has a visual on the runway, Often time they use the ILS — Instrument Landing System.

The instrument landing system (ILS) is a ground-based system that guides aircraft to safe landings during periods of low visibility or poor weather. It guides the pilot down an imaginary ramp at a shallow 3-degree angle that leads to the touchdown zone of the runway surface.

ILS works by broadcasting a narrow beam of encoded radio energy that's picked up by a special radio receiver in the aircraft. A cockpit display then shows the pilot his position and displacement relative to the guidance beam (left, right, above, below). The pilot follows this beam toward the runway until "breaking out" of the clouds to complete the landing visually. Bright lights help provide visual guidance to touchdown.

Answer 10

3 x the number of knoticle miles to landing at 1500 fps. IFR rules r used. Heading