When you think of winter weather, a few things immediately come to mind: cold, ice, snow, wind.
But according to Jet Linx Flight Coordination Manager Meric Reese, when planning a flight, there are many other considerations. “Everything takes longer. From drive times to and from the airport for both passengers and flight crew, to aircraft preparation, and airport and airspace delays, winter operations require a high level of patience,” he explained.
Whether it’s a fast-moving cold front, heavy snow, strong winds, or freezing temperatures, winter flying can create a number of challenges for flight operators. These conditions are not always hazardous – but they can be, if not planned for or handled properly. Your Jet Linx flight crew, Client Services, and Flight Coordination teams work hard to ensure the effects of winter weather are minimized, and your aircraft is safely maintained and handled during the cold months.
Winter weather forecasting has improved tremendously over the past decade, but it is still not precise enough to know exactly how a specific airport might be impacted until very near the day of a trip. Winds and temperatures are forecast very well about a week in advance, but the confidence is much lower when it comes to the timing and amount of precipitation that might fall during a winter storm. Read on to explore how Jet Linx helps you stay ahead of whatever winter has in store.
WHEN IT IS COLD AND THE WEATHER IS OTHERWISE GOOD, WE HAVE VERY FEW PROBLEMS DEPARTING FROM OR LANDING AT AIRPORTS WITH SHORTER RUNWAYSMeric Reese
“During the planning stages of the trip, careful consideration must be given to airport usage and the likelihood of needing an alternate airport. The departure airport must meet certain conditions to be able to takeoff. If snow removal or deicing capabilities are inadequate, the airport may not be usable.”
“One of the biggest considerations is the aircraft’s ability to takeoff or land on the available runway(s) when contamination exists. The FAA considers a runway to be contaminated whenever any water, snow, ice, or slush is present. “These surface conditions create the same effect on an aircraft as they do with a car – ultimately taking a greater distance to accelerate and a longer distance to stop,” said Reese. “When contamination is present, the distance required to takeoff or land can sometimes be twice as long when compared to a dry runway.” Airports must be prepared with both equipment and manpower available to remove snow and ice from surfaces. Normally, if an airport receives more than six inches of snow per calendar year, the airport is required to have a snow removal process in place.”
However, depending on the geographic location of the airport, the availability of resources can vary dramatically. “Most major northern U.S. airports will have ample funding for snow removal equipment, but many smaller county-run airports may not. Southern U.S. locations may not allocate funds for snow removal equipment, simply because they don’t see enough winter weather to justify it,” said Reese. “In those locations, an inch or two of snow can halt virtually all operations.” He further explained that most wintertime delays or cancellations are not caused by aircraft capabilities but rather airport infrastructure (or lack thereof).
Virtually all private jets are certified to handle some of the most extreme winter weather conditions, including wind, snow and ice. Winter flying does have its advantages – aerodynamic and engine performance actually increase when temperatures are colder. Air is denser, allowing the wings to generate more lift, and engines run much more efficiently than in summer months. “When it is cold and the weather is otherwise good, we have very few problems departing from or landing at airports with shorter runways,” Reese said. But with changing weather comes greater challenges.
While precipitation normally won’t prohibit departure operations, it is a major consideration for time and cost. Jet Linx operates under a “clean aircraft” concept – a method by which pilots confirm all aircraft surfaces are free of frost, snow, or ice, no more than five minutes prior to takeoff. Reese explained, “we try to keep aircraft in the hangar as long as possible to keep it warm and free of frost or ice.” Once the aircraft is pulled out of the hangar, there is a limited time available before the aircraft cools down and ice starts to accumulate.
IN FLIGHT DEICING SYSTEMS
Jet Linx aircraft have one of three types of ice prevention or removal systems that can be used while flying
Also known as the weeping wing, it works by secreting a controlled amount of de-ice fluid on different parts of the plane.
These boots have inflatable bladders which break off any accumulated ice and are installed on various parts of the aircraft
This system uses engine bleed air or electricity to heat leading edge surfaces to prevent the accumulation of ice.
THE BIGGEST ADVICE WE CAN GIVE TO OUR CLIENTS IS TO BE PREPARED FOR PLAN B.Lauren Thompson
Atmospheric conditions aloft are complex and present some unique variables during the winter season. The jet stream (a band of predominantly westerly air currents several miles above the earth) is particularly strong during the winter, sometimes exceeding 125 mph. Westbound flights therefore take longer, and aircraft burn more fuel, so fuel stops are often necessary. However, eastbound flights may be much faster and can actually save fuel, as some flights that may have required a stop in the summer months may be completed without a stop.
However, “the jet stream is sometimes unpredictable,” Reese said. “Even when it looks calm and clear, sudden movements of the air can cause unexpected turbulence.” Jet Linx pilots study these conditions and make every attempt to avoid pockets of turbulence to provide the most enjoyable flight possible.
Another major enroute factor is flying into areas of precipitation. Any accumulation of ice on the aircraft’s surfaces prevent smooth airflow over the wings, and can also inhibit engine performance. However, an aircraft’s deice or anti-ice systems can be used while flying (they cannot when on the ground). The use of these systems make flights into many precipitation types very safe. “There are limits, however,” according to Reese. “Jet Linx will not operate any aircraft into severe icing conditions.” These specific conditions are forecast by the National Weather Service, or reported by other pilots in the area.
The same infrastructure concerns exist for landing, just as they do for departure. Depending on severity of the weather, pilots must use instrument approaches for navigation to the runway. “These approaches have limits, known as minimums,” Reese said. “If cloud height or visibility is below those minimums, we are not permitted to begin the approach.” In the cockpit, a decision is made at that time to either hold and wait for conditions to improve, or divert to a nearby usable airport. “Obviously we want to get our clients to their primary destination, but we will not compromise safety by do so,” said Reese.
If approach minimums can be met, the final step is calculating runway stopping distance. The flight crew use a combination of braking-action reports (given by other pilots who have used that airport recently), and friction readings, measured by personnel on the ground. “If the runway is reported to be too slick, we will not attempt a landing,” explained Reese.
Planning for a Successful Trip
According to Jet Linx Denver Lead Client Services Specialist Lauren Thompson, “the biggest advice we can give to our clients is to be prepared for Plan B. We attempt to give our owners and clients as much notice as possible when their trip may be impacted by winter conditions. We will make every attempt to depart and arrive at the preferred airports, but sometimes that is simply not possible.”
The Flight Coordination team reviews each trip at several intervals prior to the departure date. If forecasts are available at the time of trip booking, Flight Coordination will advise Client Services of potential impacts. “This same review takes place again one week before each trip, 72 hours prior, 24 hours prior, and a final review is conducted the day of the trip,” Reese explained. If an impact is identified, Client Services will immediately contact the client to discuss options. “The sooner we know, and the more transparent we can be, the easier it is for our clients to make alternate plans,” said Thompson. “Even if we don’t know exactly what will happen, we want to make sure there are as few surprises as possible.”
Once the trip is underway, the Flight Coordination team continues to monitor the progress of the flight, and will alert Client Services if the aircraft is diverting because of adverse conditions at the destination. Thompson continued, “we plan for these diversions and always have a backup plan ready, such as ground transportation prepared for the alternate, just in case. Jet Linx partners with several vendors who are accustomed to destination changes, and who will spring into action when we need to adjust course.”
Thompson also explained the importance of knowing whether a client’s arrival is time-sensitive. “If you have a meeting, or an event where you need to be there by a certain time, it’s best to let your Client Services team know at the booking stage. If we know, we can often adjust times to still get you where you need to be, even when flight conditions aren’t ideal.”
Even when the weather cooperates, sometimes delays are inevitable. During the winter peak travel season, U.S. airspace is extremely congested with traffic. Reese explained, “there is only so much space at an airport to park, only so many airplanes that can takeoff and land, and only so much room in the airspace to move planes around at any given time. Once that space is full, the only option is to wait.” Major metropolitan areas, such as New York, southern Florida, and Chicago often implement ground delay programs, or route restrictions, in an effort to coordinate all of the traffic. “On the busiest days, U.S. airspace can see over 6,000 flights in the air at any given time,” said Reese. Jet Linx pilots make efforts to reduce delays as much as possible by filing flight plans early, and ensuring proper routes are followed. As Thompson noted, “in the event one of your trips is delayed, regardless of it being weather or airspace related, we will make every attempt to alert you early, so that you can remain comfortable in your home or hotel until the delay is lifted.”
Special Use Airports
One of the most popular destinations for Jet Linx clients is ski-country in Colorado, Wyoming and Utah. The two most popular airports are Aspen and Eagle. Because of the elevation (each airport is well over 5,000 feet high), mountainous terrain, and rapidly changing weather conditions, these airports require special attention for operations. Referred to as Special Use Airports, pilots are required to train in flight simulators on the approach, landing and departure procedures for each. Cloud height and visibility minimums are much higher and make these airports more susceptible to diversions or delays.
According to Thompson, “we like to give our clients a set of alternate airports to choose from, such as Rifle or Grand Junction, so that we can have our backup plan ready. Our pilots will do everything they can to get into or out of these airports, but they will never push the limits of safety,” she said. “If it is not safe to land, we will go to the alternate, and if we cannot safely takeoff, we won’t.” She also reminds clients that “when conditions are so bad that none of the mountain airports can be used, the Jet Linx Denver base will be happy to accommodate your arrival, and facilitate transportation to surrounding ski resorts.”
Precipitation is any form of liquid or solid water particles that fall from the atmosphere and reach the surface of the Earth. There are various forms, including:
Water droplets of 0.5mm diameter or greater
Water droplets of 0.5mm diameter or less
Irregular ice pellets larger than 5.0mm diameter, usually associated with thunderstorms
Pellets of ice composed of frozen or mostly frozen raindrops or refrozen partially melted snowflakes
Rain that falls as a liquid but freezes into a glaze upon contact with the ground
Water vapor in the form of ice crystals, mainly of intricately branched, hexagonal form
Often called soft hail, forms when supercooled water droplets collect and freeze on falling snowflakes
When the water droplets fog is composed of are “supercooled” and remain in a liquid state until they come into contact with a surface upon which they can freeze