It’s inevitable that at some point, your flight will be delayed. Many factors can cause delays, from mechanical issues to weather patterns. Airlines have different procedures for addressing delays, so it’s important to understand why flights keep getting delayed in order to make the most of the situation.
These are the most common reasons for flight delays.
- Poor Weather
- Late Arrivals
- Air Traffic Control Restrictions
- Mechanical Problems
- Crew and Pilot Availability
- Airport Staff Availability
1. Poor Weather: This is one of the most common reasons flights get delayed. Low visibility, strong winds, and heavy precipitation can cause significant delays or force an airline to reschedule a flight altogether.
2. Late Arrivals: When an inbound aircraft arrives late, it can cause delays for outbound flights as well. Airlines must be able to account for unforeseen circumstances, such as delays in connecting flights. This can cause a ripple effect of delays throughout their network.
3. Air Traffic Control Restrictions: Air traffic control (ATC) regulations often cause flight delays, especially during peak travel times. ATC’s job is to manage the airspace and ensure that aircraft can fly safely and efficiently. The restrictions can be because of many reasons, such as high-traffic congestion.
4. Mechanical Problems: Aircrafts and their components are complex machines that require regular maintenance in order to keep them operational. When something goes wrong with an aircraft, it may cause significant delays until the issue is resolved.
5. Crew and Pilot Availability: Pilots and flight crews must be carefully managed in order to ensure that all flights run on time. When a crew member or pilot becomes unavailable, the airline must scramble to find a replacement before the flight can take off.
6. Airport Staff Availability: Similar to pilots and flight crews, airport staff needs to be carefully managed to ensure personnel are available to clean, refuel, and taxi the plane when needed. There’s a lengthy checklist of tasks that must be complete before passengers can board the plane for takeoff.
Unfortunately, it can’t always be sunny and 75 with a light breeze. While planes are built to withstand the harsh elements above the clouds, they first must get past the sometimes-harsh conditions below the clouds.
Poor weather conditions can cause significant delays or even force airlines to reschedule flights altogether. According to the FAA, the most common weather hazards that delay flights, and account for nearly 70% of all delays in an average year, are:
- Wind shear
Airplane Weather Delays in 2022
While the FAA claims weather accounts for nearly 70% of all delays, the Bureau of Transportation Statistics reports that only around 25% of all delays are related to weather, based on 2022 data.
Other major causes for flight delays included:
- Air Carrier Delay
- Aircraft Arriving Late
- Security Delay
- National Aviation System Delay (non-extreme weather, airport operations, heavy traffic volume, air traffic control, etc.)
- Canceled or Diverted
Aircraft arrivals and departures are scheduled to the minute, as you can see on your plane ticket. However, when one plane runs late, it can cause a domino effect, delaying many other flights throughout the delay.
Again, bad weather, air traffic delays, mechanical issues, and other unforeseen circumstances at other airports can cause further delays to happen.
Airlines will do their best to hold a plane a reasonable amount of time to allow for passengers to make a connecting flight if they’re running behind.
Air Traffic Control Delays
Air traffic control maintains the safety and efficiency for the nearly 10,000,000 departures that occur annually.
With the US alone having 8 of the busiest top 10 airports in the world, as reported by the Port Authority of New York and New Jersey, air traffic control is regularly faced with decisions that must be made to ensure the safety of passengers and the efficiency of flights.
When traffic levels become too high, ATC will often restrict flights from taking off or divert them to different runways. An airplane on the ground, in the terminal, will always be significantly safer than on the runway or in the sky.
Airplanes, like cars, have mechanical parts that must be maintained. Even with proper maintenance and regular tuneups, parts and components still break and repairs will need to be done.
However, unlike cars, aircraft maintenance is highly regulated and is under extreme scrutiny around the clock.
One reason there are so few plane crashes or accidents is because of the many checks and procedures that must be followed before and after a flight.
For example, below is a list of some checks and reviews by technicians, as described by a former Quality Assurance Maintenance Officer in the US Army:
- Pre flight inspection
- Post flight inspection
- Maintenance identifies and diagnoses a problem
- A technician ensures the tools and components are available to fix the issues.
- Maintenance fixes the and records the procedure in the maintenance log book.
- Quality assurance checks the technician’s work.
- For some specific components, another check is performed by the technician or pilot to ensure the component works correctly.
Crew and Pilot Availability
One of the key components to having a successful flight and preventing delays is crew availability.
Life happens and sometimes attendants, pilots, or other flight crew members get sick. When a crew member gets sick before their next flight is supposed to depart, a substitute has to be found.
While a specific number of pilots are required for every flight, a specific number of flight attendants is also required.
Pilot Flight Hours
The FAA mandates a set amount of hours pilots can fly in a given period of time, followed by another set period for when pilots are required to rest.
The majority of the time, airlines can account for this, but occasionally other delays and circumstances can create odd circumstances.
For example, on one flight from JFK to Jacksonville, Florida, a flight was being taxied to the runway, when the pilot came on the intercom and stated that because of federal regulations and him [the pilot] reaching is hourly max for the day, they had to return to the gate.
You would think the airline would have foreseen this, right? Normally, yes, but if this had originally been scheduled to depart several hours ago, but was delayed due to, say, mechanical issues,
Pilots have a 14-hour duty period and a shorter flight can be completed in less than a few hours. However, if it’s delayed by several hours while the plane is loaded, a pilot could easily hit the maximum hour duty period.
What is defined as a Flight Duty Period?
Flight duty period (FDP) means a period that begins when a flight crewmember is required to report for duty with the intention of conducting a flight, a series of flights, or positioning or ferrying flights, and ends when the aircraft is parked after the last flight and there is no intention for further aircraft movement by the same flight crew member.
A flight duty period includes the duties performed by the flight crew member on behalf of the certificate holder that occur before a flight segment or between flight segments without a required intervening rest period.
Airport Staff Availability
Just as you need to have people direct air traffic and fly the planes, you need even more people in operations to aid in getting the plane ready for its next departure.
If people get sick, don’t show up for work, or can’t do the job efficiently, delays will happen. To give you an idea of the operation roles at an airport, here are some tasks that need to be performed in between each flight:
- Clean the seats, trays, and other areas of the plane
- Unload the baggage for previous passengers
- Inspect the plane for any damage
- Load the new passengers
- Load the checked baggage of passengers
- Load food, fuel, and other cargo
How often do flights get delayed?
Based on the data we’re reviewing, a flight is considered delayed if it arrived at (or departed) the gate 15 minutes or more after the scheduled arrival (departure) time.
- In 2022, approximately 21% of flights have been delayed. 76.2% have departed on time and 2.8% have been canceled.
- In 2019, approximately 18.8% of flights had been delayed. 79% had departed on time and 2.2% had been canceled.
Years 2020 and 2021 are available on the BTS website, although they have been committed here due to being outliers as a result of the Coronavirus Pandemic during those travel years.
How long can a flight be delayed before canceled?
There is not set time length of time a flight delay has to reach before it is canceled. Cancelations vary based on the airline and its procedures.
By law, airlines are required to update passengers within 30 minutes or sooner after the airline becomes aware of a status change. This status update, at a minimum, must be provided on the airline’s website and via the airline’s telephone reservation system.
When a flight is delayed 30 minutes or longer, the airline must update all flight status displays and other sources of flight info at US airports under the airline’s control within the 30 minutes after the airline becomes aware of the problem.
Many airlines will wait until the last minute to cancel a flight if they are not able to get it off on time, in order to give passengers more time to make alternate arrangements.
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