Last call for boarding! Air travel maybe stressful for some and eventful for others, no matter what time of the year it is. Although the wintertime travel comes with some extra baggage: winter weather and the frigid temperatures.
Keeping faith that there won’t be a change in your flight status could prove to be a challenge. A major winter storm is already leading to widespread delays and cancellations. But not the cold alone, at least not anymore, thanks to a process called deicing.
Of course, it's no surprise that powerful winds, wintry precipitation and blizzard-like conditions generated by a potent winter storm are enough to keep planes grounded at the gate. The risks of flying in such conditions are too grave. But what about the cold alone?
Aircrafts are built to withstand frigid temperatures. If you ever checked out the flight map and information onboard, you probably could confirm this. When the plane reaches higher altitudes, it flies through bitterly cold temperatures- not just in the winter, but year-round!
Soaring through temperatures as cold as -70 degrees Fahrenheit at 40,000 feet is no problem for most modern aircraft. In fact, planes can actually perform better in the cold, as the denser air allows for more lift and for the engine to operate more efficiently. In the air, that is.
On the ground, severely cold temperatures could threaten a safe take-off or landing, especially when there’s any available moisture involved. But there’s a solution (literally) to prevent this: deicing.
When temperatures fall below freezing, any moisture that comes into contact with the cold metal surface of the aircraft will freeze.
While this might not seem like a big deal initially, layers of ice and wintry precipitation could impact the instrumentation and functioning of the aircraft itself, reducing its ability to fly safely. To prevent this, we must deice a plane.
If you travel during the winter months, chances are you probably heard of the term before. But what is deicing essentially?
The Federal Aviation Administration (FAA) defines deicing as removing ice [from an aircraft] after it has formed. Although this process doesn’t just refer to the removal of ice alone, but also includes the removal of any snow or frost that built up on the surface of the aircraft.
This process is essential to ensure a safe flight.
Jim Decker, United Airlines Director of Ramp Operations at Dulles International Airport in Virginia, describes the typical deicing process, which usually involves two solutions, a Type I and a Type IV.
When temperatures are below freezing, they use a Type I solution first, which comprises 50% propylene glycol and 50% water. The solution is heated and sprayed on the aircraft to remove any ice or snow on the aircraft.
If freezing precipitation is falling as the plane gets ready for take-off, they will spray the plane again, only this time with the Type IV solution, which comprises 100% glycol, preventing ice and snow from adhering to the wings and tail of the plane.
Decker clarifies that this solution, "is not sprayed across the entire aircraft, but rather just the critical areas, such as the wings and the tail."
The FAA mandates that all aircraft are free from ice, snow and frost prior to take-off, commonly known as the "clean aircraft concept". Failure to abide by this could lead to devastating consequences.
Decker further mentions that, “If there is ice or snow on the wings or tail of a plane, that can prevent the plane from having enough lift to safely take-off, so deicing is very important when the weather gets colder. Without lift, planes can’t become and stay airborne.”
Unfortunately, not properly deicing an aircraft in the past resulted in catastrophic outcomes.
On Jan. 13 1982, failure to deice a plane once more prior to take-off lead to a deadly disaster in our nation’s capital.
Following a winter storm, a delayed Air Florida Flight heading to Fort Lauderdale attempted to take-off. It was only in the air for a short time before it crashed into the 14th Street Bridge crossing over the Potomac River. The disaster that took 78 lives that day was due to pilot’s error.
Even though the plane was initially deiced, delays prolonged its time sitting out on the tarmac. Because of this, it has to be deiced again prior to take-off.
Decker highlights the importance behind the “holdover time” and how it determines the frequency of which planes should be deiced given the weather conditions on that day.
He explains, “After a plane is deiced, a clock is set for holdover time, which measures the time between when the team sprayed the Type IV fluid to the time that the aircraft actually takes off from the runway. The holdover time is determined by the precipitation, temperature and aircraft type. The colder it is, the shorter the holdover time is.”
Decker expresses that, “If the plane waits too long to take-off at an airport and exceeds its holdover time, it may need to be sprayed again prior to being able to take off.”
In another instance, ice building up on the wings also lead to the fatal crash of Flight 3470 that was headed to Buffalo back in Feb. 2009.
Even when the plane takes off safety, pilots still need to be aware of ice forming on the plane while in flight as well. Thus, it is essential they must pay close attention to the current weather conditions, as well as the ones that they could encounter en route to their destination.
Knowledge of the types of icing and how they can impact an aircraft's performance are key to making sure everyone onboard stays safe. To learn more about the different types of icing and its potential hazards, the National Weather Service (NWS) breaks it all down here.
As a peace of mind, though, most commercial aircraft nowadays have in-flight deicing systems that prevent this from happening.
Combating the cold takes careful through and preparation, which is why airlines have specially designated teams dedicated to its deicing procedures alone.
Decker discusses how United’s deicing crews train thoroughly in the summer months in order to prepare for winter operations. Even though these teams are ready to go in the fall, the busiest times are by far during the months of December and January.
Regardless, standard regulations require planes to deice when temperatures fall below freezing. Still, Decker reminds us that this process is “a calibration between the deicing team and the pilots. But ultimately, the pilots inspect planes ahead of departure to determine whether deicing is necessary.”
The total time to deice a plane can range from under 10 minutes to 25 minutes for smaller jets, but could take as long as 45 minutes for wide-body aircraft. So, the decision to deice a second time before take-off could cause a late arrival to your destination.
Despite the additional delays deicing may bring, though, at least it shouldn’t put a total freeze on your winter travel plans.
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