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Why Do Flights Get Delayed – 15 Reasons Why Your Next Flight May Be Delayed

Why Do Flights Get Delayed? I’m Glad You Asked

Flight delays are inevitable. After flying my share of airlines (173 so far), I’ve seen many flight delays. When you fly using that great travel deal, most of the flights are ontime about 80% or so of the time, the other 20% or so of the time the delays are due to several reasons. In the U.S. ontime is counted as any departure/arrival within less than 15 minutes of the scheduled time and the Bureau of Statistics keeps track of it all. Still wondering why do flights get delayed?

When you think about it though, 80% is pretty impressive considering the enormity of the operation. Travelers get really upset when flights are delayed and that I can understand, so I’ve put together 15 reason why your flight may be delayed the next time you travel to help you understand how it all works. Oh, my suggestion is to download the Apps from the airlines as they have a facility to keep track of your flight and receive updates.

There’s also a nifty Web site done by the Federal Aviation Administration (FAA) where you can get flight delay information.

Why do flights get delayed - Flight Delay Causes for U.S. airlines in 2017
Why do flights get delayed – Flight Delay Causes for U.S. airlines in 2017

Travel Insurance

Before I delve into the 15 reasons below, I suggest considering travel insurance when you travel as this helps to mitigate the costs associated with flight delays. Some services have what’s called Trip Delay Insurance. And remember if your flight cancelled as sometimes happens with delays, you are entitled to a full refund from your air carrier.

The airline is also responsible to get you to your destination within a set amount of time depending on the country from which the airline is operating and/or where it is based. You may also be eligible for financial compensation depending on the routing of your flight. You can always find these rules on the airline’s web site in the Contract of Carriage. My fellow traveler Mike here talks about delay compensation in details.

Here are the 15 reasons in no particular order:

1. Waiting for connecting passengers

Airlines do this all the time to ensure that you get to your destination. Typically the Captain will make an announcement so you know what’s going on. And they’ll sometimes add that “if it were you, I’m sure you’d appreciate us waiting for you.”

Connection Flight Board in Singapore
Connection Flight Board in Singapore

2. Waiting for connecting bags

Sometimes your bags take a little longer to get from one plane to the next so the ground handlers will advise the Captain that they are waiting for some more bags to arrive from other flights.

Why do flights get delayed? - Bags in San Jose, CA
Bags in San Jose, CA

3. Waiting for cargo

The airline industry actually started with cargo; passengers were an after thought :-). If you happen to look out the window, you’ll sometimes see the cargo being loaded. Cargo is big business and people pay just like you do, sometimes a little more to have their cargo delivered at a specific time. Sometimes it arrives at the airport late, or there’s a lot of it or a lot going on and it may take longer to load than normal. As an FYI, the US Postal Service is one of the customers of the airlines, so your “air mail” is carried by the U.S. airlines.

Loading Cargo
Why Do Flights get delayed – Loading Cargo

4. Loading cargo

As mentioned in #3 above, it takes quite some time to load the cargo. All kinds of things are carried by cargo. I’ve seen cars, horses, machines, airplane engines, you name it being loaded. The Boeing 747-Combi operated by KLM takes cargo and humans on the same deck; typically the cargo is carried under the passenger deck. I’ve had the opportunity to peek in and see the cargo and its pretty amazing. KLM actually has a flight attendant that takes care of the horses they carry on the Houston to Amsterdam flight. Very cool if you get to see it in action.

Why Dp Flights Delayed - KLM Boeing 747-400 Combi in Amsterdam
Why Do Flights Get Delayed – KLM Boeing 747-400 Combi in Amsterdam


Why do flights get delayed? - Cargo in Tokyo-Naroita, Japan
Cargo in Tokyo-Naroita, Japan

5. Loading bags

You passengers carry a lot of stuff and you want to be able to pick them up on the other end. Sometimes there are an unusual amount of bags or the ramp folks are running late. So the passengers are boarded, but the bags are not. The airplane can’t go anywhere until the cargo doors are shut, so this delays the flight.

United Airlines Boeing 747-400 loading cargo
United Airlines Boeing 747-400 loading cargo

6. Security

You don’t really see this but there is quite a bit of security details behind each and every flight. Sometimes there are issues that have to be corrected before the flight departs. As an example, each time an airplane arrives into a foreign country, there is a series of security clearances that must be adhered to before the airplane departs again. This all takes time and most of the times is done in time for departure, but like everything else, there are sometimes issues and these cause delays.

Why do flights get delayed? - Taking off from LAX
Taking off from LAX

7. Boarding passengers

The airlines have this figured out. They have metrics by aircraft type and destination as to how long it takes to board a flight. You can see the end result of this on your boarding pass. But as humans, we don’t want to get to the airport/gate early so we lounge around waiting to board last or something like that.

I’ve seen people sit at the gate and not move when their flight is announced and when the agent is ready to close the door, they jump up and want to be boarded. You can mitigate this by showing up to board at the time it says on your boarding pass.

Turkish Airlines (TK) Boeing 777-300 boarding in Istanbul, Turkey (IST)
Turkish Airlines (TK) Boeing 777-300 boarding in Istanbul, Turkey (IST)

8. Weather

This is perhaps what you encounter the most, but its actually a very small percentage of the reasons for delays. The system is one complete system so a weather condition in say the West coast of the U.S. can affect the flights on the East cost of the U.S. since the planes that are making up the flight on the East coast is coming from the West coast. Weather delays are expensive to the airlines; any delay is really. Typically, you are not compensated when you have a weather delay. However, you are entitled to a refund if you have a cancellation. But if you are nice to the agents and you are a super elite member strange things may happen… 😉

Bad weather near Heathrow Airport London, United Kingdom
Bad weather near Heathrow Airport London, United Kingdom


So are you more convinced about why do flights get delayed? Read on foe some more reasons.


9. Waiting for crew

As mentioned before, the system is one big connected system, so unless its a morning flight, your crew is more than likely coming from another airport. But of course it depends on where the flight is going. If you are in a hub, there is usually crews standing by; but oftentimes, the crew for your flight came from another flight and if that flight is delayed getting in, then so is your crew. Nothing you can do about this one, but just wait it out.

Sometimes the airlines will board the flight as there is enough crew onboard to make it safe and then wait for the pilots. But you can never board unless there is an adequate amount of flight attendants, typically one for every 50 seats on the plane.

Taking off from Newark Airport and seeing New York City at night in British Airways Boeing 787
Taking off from Newark Airport and seeing New York City at night in British Airways Boeing 787

10. Mechanical delay

I know you must hate this one. I do too; but I get it. Once a delay is announced, you are perhaps saying, how come you never knew this before? Well, the pilots run checks just before the airplane leaves and oftentimes these issues show up then. Better on the ground than in the air of course. They they try to fix it themselves with the help of the operations team as they have set troubleshooting procedures. If they fail, then you get the dreaded message that you have to return to the gate.

At this point you want to get off the plane, but can’t since they think it won’t take too long and then it does. Not much you can do here, but just know that the professionals are at work. Chill, get on your phone or mobile device (if allowed) or read a book is all I can advise. If you are in First class, you are perhaps served drinks :-).

Lufthansa Airbus A321 at gate in Frankfurt
Lufthansa Airbus A321 at gate in Frankfurt

11. Airport congestion

Sometimes you land and then it takes forever to get to a gate or on your take off, you have to wait to leave your gate and even worst, wait in line for the take off. This happens a lot at say LaGuardia, JFK, London-Heathrow, those really big airports that are quite popular. It’s bad sometimes as you are all ready to go, but you hear the Captain say that there’s an airplane behind us so we can’t go anywhere.

SAS in Tokyo-Narita, Japan (NRT)

12. Air Traffic Control (ATC)

Air Traffic Control (ATC) is a very important part of the aviation system. Sadly its overloaded; i.e. too many airplanes in the system and the equipment is quite old. When I was a Masters student at Embry-Riddle in the early ’90s, I actually worked on a project that would look at the overloaded system with a view to improving it.

So don’t think that no one is looking at it; they are. In an effort to keep the system safer than it already is; as an example, when there is say weather happening fewer planes are allowed to be flying. So you hear the Captain say our takeoff is being delayed due to an ATC hold.

Alaska Airlines Boeing 737-800 in Las Vegas, NV
Alaska Airlines Boeing 737-800 in Las Vegas, NV

13. Weight restriction

Airplanes are designed with something called Maximum TakeOff Weight (MTOW), so every bit of weight that goes on the plane counts. So in short the operations team at the airlines figure out all that stuff in the background. Sometimes they wait until the last minute since that’s when they get the most up-to-date airport conditions and all the bags and passengers are loaded.

This happens on longer routes and routes to mountainous area and areas that are high above sea level. The delay is caused as they wait until the very last minute to make the decision as that’s when they have the most up-to-date information. So they may have to pull baggage or passengers so the flight can operate. Typically they will pull airline staff that are traveling.

Airplanes in Tokyo-Narita, Japan
Airplanes in Tokyo-Narita, Japan

14. Catering

You got to have food on the plane even if you have to pay for it. Sometimes, this is the reason for the delay as the catering trucks are catering other flights. I was in the new Hong Kong airport on opening day and the caterers could not find our plane so we were delayed due to catering. Just sit tight and wait as not much you can do here either.

Economy Class Meal on a Turkish Airlines Boeing 777-300ER
Economy Class Meal on a Turkish Airlines Boeing 777-300ER

15. Aircraft preparation

It takes a lot to get that airplane prepared and ready to go. The operations team is in charge and lots of communication is going on behind the scenes. But of course sometimes it goes awry and delays the flight. Things like the airplane not cleaned in time; fuel is delayed, etc. will happen. Again, nothing you can do here but just wait.

Jetstar pushing back in Singapore
Jetstar pushing back in Singapore

What else have you seen happen during your flights? Please leave a comment below and also share with your friends so they too can understand why do flights get delayed.

7 thoughts on “Why Do Flights Get Delayed – 15 Reasons Why Your Next Flight May Be Delayed

  1. above context looks only to west while in east at time there are missing passenger and lot of announcement etc.

    1. Yes. Missing passengers is an issue as people decide to stop and shop in airports. Airlines will generally page these passengers, but at some point they have to go.

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