Hearing that the plane is making its final descent is one of the best parts of flying since it indicates you’ll be landing soon. So when do planes descend?
When flying under Instrument Flight Rules (IFR), the decision to begin descending is made by Air Traffic Control based on air traffic, destination conditions, airport traffic, and more. This will usually end up being roughly 20-30 minutes before the scheduled landing time at the destination.
You’ve probably heard that the plane is making the final descent to the airport, yet you still don’t seem to land forever. This is because it takes a while for a plane to reach landing conditions. In this article, you’ll learn everything you want to know about when planes start descending including how long it takes to descend and land, how fast planes are going, whether autopilot handles the descent for the pilots, and more.
Here at SkyTough, we are focused on providing only the best, most helpful content to our readers. To ensure that we do this every time, we combine our own knowledge and experience with the opinions of others in the industry to provide the full picture. That way, you get as much information as possible and you can read this article with the confidence that you’ll know everything you want to know about when planes start descending.
How Do Pilots Know When To Start Descending?
When you’re flying commercial, it can be tough to have any real idea where you're located in the sky or how far you have left to go. Especially on longer flights, it sometimes seems like they just go on forever. While some of the major airlines these days have monitors built into the seats in front of you that you can track the flight on, that’s not always the case.
As a passenger, it can be almost impossible to know where you are in the sky. Even with the flight tracker that you can keep your eyes on throughout the flight, you don’t really know where you’re truly at. But pilots have access to a lot more navigation tools to make sure they know exactly where they’re flying. Even so, how do they know when they can start descending as they head towards the airport?
Knowing when to start the descent is a crucial part of flying an airplane so that you don’t endup descending too quickly. Too fast of a descent rate can cause potential pressure changes in the cabin, it can scare passengers, and Air Traffic Control (ATC) might think you have an emergency. So it’s important that, as a pilot, you start the descent at the proper time, speed, and altitude to have a slow and steady descent.
When it comes to actually knowing the right time to start descending, it really depends on if you’re flying under Instrument Flight Rules (IFR) or Visual Flight Rules (VFR). The vast majority of all commercial flights operate under IFR, under which ATC will dictate when to begin your descent based on air traffic, the conditions at the destination airport, airport traffic, and more. Under VFR, pilots of small aircraft will typically use their onboard systems to come up with a descent rate of 500 feet per minute (fpm) as they cruise into the airport.
How Fast Are Planes Going During Descent?
One of the most important parts of flying an airplane and beginning the descent is how fast you’re flying. Depending on the type of plane, you could be going anywhere from around 100 mph to upwards of 600 mph or more at cruising speed. And once you hit the runway at the destination airport, you’ll need to quickly bring that speed down to 0 mph (or at least whatever speed you will be taxiing at).
So then how fast do planes actually go during descent?
Descending at the proper speed is essential for a safe flight and a more straightforward landing. Flying too fast and you could overshoot the airport or be going too fast to make a safe landing. Too slowly and the plane could lose power and potentially even stall depending on the aircraft. Not only does your horizontal airspeed matter, but you also want to make sure your descent rate is not too fast as mentioned above. So descending with the right speed can be a bit challenging.
Let’s take a quick look at commercial airplanes and how they descend.
Commercial Airplane Descent And Landing
If you’re flying in a commercial airplane, you’re probably cruising along during much of the flight at around 500-700 mph. At these speeds, you can imagine how difficult it would be to land an aircraft. Just imagine sitting at an airport and seeing a plane coming in at 700 mph to the airport. That would not be a pretty sight. Commercial planes typically land at around 150 to 165 mph, so the pilot must drastically reduce the plane’s speed during descent.
In most cases, once the plane is about 20-30 minutes away from its destination (which of course will include the time it takes to descend — more on that shortly), ATC will come over the radio and give the pilot the go-ahead to begin their descent into the airport. Experienced pilots will be able to tell when they’re getting to a point that they would need to start descending shortly or else the rate of descent could be too fast, and they’ll radio to ATC and ask.
Once ATC gives the go-ahead to begin the descent, whether that’s on their own accord or following the pilot’s question, the pilot can begin descending towards the airport. To begin slowing the plane, the pilot can reduce power, raise the flaps, lower the landing gear, or any other combination of things that will either increase drag or reduce thrust. Both of these will cause the plane to slow down and allow the pilot to safely approach the runway.
How Long Does It Take To Descend And Land?
When you finally hear the pilot come over the radio and announce to the passengers and crew that they’re preparing for final descent, it can be a relief! But sometimes it can seem like the flight just continues to go on and on. So how long does it really take for a plane to go from cruising speed and altitude to landing on the runway and safely coming to a stop at the gate?
Commercial planes will typically fly at around 30,000 to 43,000 feet in the air. As the pilots begin preparing for landing, they’ll typically descend to an altitude of around 10,000 feet before truly descending towards the airport. Going to this lower altitude will of course need approval from ATC as well, but this common practice is done to prevent the aforementioned rapid descent that can be damaging to passengers and crew.
From 10,000 feet, pilots will then begin truly descending towards the airport. They’ll try to keep it fairly slow and steady, dropping at a rate of around 300-500 fpm. This alone equates to around 20 to 33 minutes of descent, which is right in line with how long you can realistically expect to land once you hear the pilot say they will be starting the final descent to the airport!
Also keep in mind that while the plane is dropping steadily from tens of thousands of feet in the air to the ground, they’re also slowing down from 500-700 mph to around 150-165 mph for landing. This is another reason why the descent takes longer than you might think. Realistically speaking, a plane could likely descend in less than 10 minutes. But between the rapid drop in altitude combined with the hard air braking required, it would not be a comfortable ride!
About THE AUTHOR
After spending years watching every video I could find about flying, I finally scratched the itch and got my pilots license. Now I fly every chance I get, and share the information I learn, here.Read More About Joe Haygood