Keep snow cleared for takeoff
Nothing can shut down an airport as fast as a winter storm. But with a well-planned snow and ice management plan, airport crews can keep travelers on schedule.
By Tom Long, Pittsburgh International Airport
Hour after hour, the snow kept falling.
Inch by inch, it piled up and slowly began to bring a fast-moving city to a crawl.
It was March 1993, and one of Pennsylvania’s worst winter storms in history was taking its toll on Pittsburgh, dumping 27 inches of snow in the area.
The following year, a similar storm hit the area, this time leaving 24 inches of snow.
Each time, the snow-removal crew at Pittsburgh International Airport sprang into action. It’s goal: to provide safe transportation for air passengers with few interruptions of service.The proof is in the planning
Although the past few winters have not brought severe winter conditions to Pittsburgh, the maintenance and operations staff at Pittsburgh International Airport have continued to develop and maintain high standards when it comes to snow and ice management.
These departments begin to prepare for harsh weather almost as soon as the previous winter ends. Maintenance of snow-removal equipment begins in earnest each April as every vehicle is given a bumper-to-bumper inspection. Spring is also the time to critique the previous season’s winter operations.
During the summer, airport crews order snow-removal equipment parts, broom bristles and plow blades, and they begin to formulate a revised annual winter-operations plan. The primary objective of the plan is to maintain maximum safety at all times on runways, taxiways and other areas of the airport.
The plan outlines staff responsibilities, snow removal priority listings, aircraft deicing techniques, emergency deicing fluid disposal procedures, standard gate and runway deicing procedures, inspection and reporting techniques, communications techniques and equipment inventory. This, of course, all seems logical and simple, but staying on top of the routine issues is the most critical aspect of being prepared for the following winter.
An ounce of prevention
At Pittsburgh International Airport, the access and fire department roads receive first priority for snow removal, followed by prevailing runways, appropriate taxiways and, finally, deicing pads and aprons.
While the airport has an organized and experienced snow-removal crew and ample equipment, it first utilizes state-of-the-art preventive maintenance techniques to achieve maximum operations for all of its runways. Sensors that relay runway conditions and surface temperature to a constantly monitored computer are embedded in the four runways that serve Pittsburgh International. The airport also maintains 24-hour contact with a contracted weather service, in addition to its satellite feed of weather updates.
These three preventive measures not only save the airport millions of dollars over years of use, but they help provide some of the safest conditions for pilots and their passengers.
The sensors indicate when crews need to apply liquid deicing fluid to the runways, eliminating guesswork when it comes to the surface temperature of the runway. Additionally, constant communications with the weather service means the airport snow-removal crew will be prepared if and when the ice storm hits.
When a severe ice storm is predicted for southwestern Pennsylvania, that is a signal to prepare the 10 deicing trucks that will spray liquid potassium acetate on runways and ramps. This is done in conjunction with the sensors indicating the runway surface temperature has reached 34°F or colder.
The airport has also employed five new deicer trucks that can handle 1,500 gallons of fluid. What makes them unique is a front-discharge spray bar that was designed at Pittsburgh International Airport. This design has eased the spraying around the aircraft and gates because these trucks are smaller and do not have to back into tight areas—as do trucks equipped with only rear-end spray bars—to spray the deicing solution.
The liquid potassium acetate sticks to the runway and prevents ice and snow from bonding to the surface. It is a process that crews must repeat throughout the day if it is raining and freezing rain is still in the forecast. Preventive measures with freezing rain and ice are imperative, because ice is a bigger threat to an airport than any snowfall.
Under normal winter conditions, however, the airport snow-removal crew works effectively to keep the airport running safely. It helps that Pittsburgh International Airport has three parallel runways and a crosswind runway, which make clearing snow a little easier task. The parallel runways allow crews to close a runway without having too much crossing traffic. That lets them concentrate on the runway at hand with few interruptions.
Communication is key
In the 50 years Pittsburgh International Airport has been in operation, closures due to winter-related storms have been minimal. That is a testament to the work ethic of the snow removal crew, which includes field maintenance personnel, operations staff and electricians, as well as Federal Aviation Administration (FAA) tower personnel.
One unique feature that the airport implements during winter storms focuses on communication. When the snow-removal crew is in action, the FAA tower supervisor communicates directly with the operations snow-removal leader on the airport’s private radio channel. This facilitates snow removal by making communications one-on-one: FAA to operations leader, which ensures accurate communications so that runways can be cleared both safely and swiftly. This communication makes snow and ice management safer and much more effective, which is one of the reasons Pittsburgh International is consistently rated as one of the world’s leading airports.
Pittsburgh International Airport’s snow-removal equipment includes: 14 18-foot wafer brooms, 10 snow blowers that eat and blow (200 feet away) 2,500 to 5,000 tons of snow per hour, 10 front-end loaders with eight 20- to 24-foot ramp hogs, four graders, 12 sanders, 13 28-foot plows and one 12-foot roll-over plow.
When there are two inches or less of snow, crews use mostly brooms with a couple of plows and a blower to clear the runways.
With more severe weather conditions, however, come more advanced procedures. When more than two inches of snow falls, nine of the 28-foot plows lead the charge, each followed by an 18-foot broom. Crews usually place a blower after every fourth plow-and-broom combination to clear the windrow (the row of snow left by the outer edge of the plow). The 24-foot ramp hogs push back the intersecting taxiways.
If needed, sand, liquid deicer or sodium acetate is applied before the runway is reopened. This entire process, which starts on the runways and works its way in to the taxiways and, ultimately, the gates, gives the pilots the safest conditions possible on the ground.
It is a system that works. Our performance in severe weather is proof.
Although recently southwestern Pennsylvania rarely has enough snow to qualify for the Balchen/Post Award for Excellence in the Performance of Airport Snow and Ice Control (which is given by the Northeast Chapter of The American Association of Airport Executives’ annual International Aviation Snow Symposium), Pittsburgh International Airport has earned this honor four times, in addition to its five honorable mentions.
That prestigious award is not only a testament to our equipment and our planning, but, most importantly, to the operations and maintenance crews as well as all the employees of Pittsburgh International Airport, who take great pride in the success of the airport.
Tom Long is director of maintenance for Pittsburgh International Airport (Pittsburgh, Pa.).
Adhering to the rules of traction
Anti-icers and deicers are undeniably good tools for snow and ice removal, but are they right for you?
By John Habermann, Purdue University
Snow and ice control is becoming more important to more people and agencies with each passing season. As local government agencies work to supply timely snow clearing, they are discovering that local contractors can assist them. Also, private businesses are realizing the economic benefits of having a timely snow and ice control plan. It is you, the local contractor, who is being hired to assist with and provide snow and ice control. And although much of the equipment owned by local contractors can be retrofitted for winter maintenance, many of you are finding yourselves void of the technical expertise needed to properly "equip" you for such work. And if you do decide to expand your business to include snow and ice control, you may find yourself in need of answers to these questions: What chemical is best? What is de-icing? What is anti-icing? What are the proper application rates? How much training do I need to invest in my drivers? Who does the training?
There is not room enough in this article to answer all these questions in detail, but in the next few paragraphs, this article will provide you with some general guidelines to use in snow and ice removal as well as point you to additional resources.
To anti-ice, or not
Your first step is to determine your customer’s expectations. Some customers want anti-icing, some want de-icing, some want both and some may not be sure of the services that are available. Part of your job is to help educate your customer by describing the different options. Before you do that, you may want to decide for yourself and your company what services you want to offer.
Anti-icing and deicing techniques help make snow plowing more effective. By applying these products before you plow, you are removing more snow and ice from the driving area than you would be if you did not use anti-icers and deicers. It’s up to you if you want to implement such a program. Consider your ability to monitor weather and evaluate your response time. It may be better for you to wait for an accumulation of snow before taking action. Many contractors have a 2-inch accumulation contract, which stipulates that they will not begin plowing until there are 2 inches of snow on the ground. If this is the case, you should expect to face some contractual disputes if you do decide to anti-ice. For example, you may decide you would like to anti-ice because meteorologists are predicting a heavy snowstorm. If you anti-ice and there is no snow accumulation, you and the owner may disagree as to how, if at all, you are to be compensated for such work—especially if it’s not outlined in the contract.
Depending on your work crews and their ability to respond in a timely fashion, a de-icing program may give you time to get a game plan together and organize while the accumulation is taking place. However, the other point is that anti-icing, if effectively done, can save you time (i.e. money) by enabling you to cover more ground in a shorter time period.
More than you can shake a stick at
You have a plethora of products from which to choose if you decide to implement anti-icing and deicing into your snow-and-ice removal program. However, those most commonly used in the snow-and-ice control industry (and, in general, the lowest temperature at which the chemical is most effective) are:
Sodium chloride (rock salt) (+15oF to +20oF)
Calcium chloride (-25oF)
Magnesium chloride (+5oF)
Calcium magnesium acetate (+20oF)
Potassium chloride (+25oF)
Agriculture products (varies)
Remember that all of these chemicals have pros and cons that you need to evaluate before deciding which one is best for your snow-removal applications. You can find information on the Internet at the following web sites:
The National Research Council of Canada, www.nrc.ca;
Federal Highway Administration (reports online), www.fhwa.dot.gov;
Turner Fairbanks Highway Research Center (July/Aug. 2000 issue of FOCUS), www.tfhrc.gov; and
National Local Technical Assistance Program (LTAP), www.ltap.org/LtapOrg/docs/innovations.
There are 56 LTAP centers throughout the United States. If their region is involved with snow and ice issues, then they will have the latest information on snow and ice chemicals (for example, the Hawaii LTAP Center does not have an extensive collection of snow-and-ice control videos). For a complete listing of LTAP centers, visit www.ltapt2.org/list.htm and lookup the LTAP center that serves your state. If you are involved with helping a local community with snow and ice control, then your LTAP center can assist you.
In terms of other resources, your state’s Department of Transportation has, more than likely, researched various anti-icing and deicing chemicals and could share with you which ones (and combinations) work best in your area. If you have access to e-mail, you can join a list-serve that is hosted by the University of Iowa. When you join (for free), you will have access to more than 400 people who are involved with snow and ice control in North America, Japan and Sweden. You can e-mail a question to the list-serve address and watch the answers come in. To join the list serve, send an e-mail to email@example.com and request them to sign you up.
Remember, not all snow-and-ice control jobs require chemicals. Whether you use them or not is up to you and should be considered on a case-by-case basis. You must consider that an anti-icing or deicing program will require storage of materials and additional equipment. Think about whether your winter work will pay for this additional investment in materials and equipment. It truly depends on your particular situation.
WINTER MAINTENANCE GLOSSARY
Here are a few common terms you will come across as you pursue winter maintenance work:
and ice control. The key word in this phrase is "control." Control
is defined as "to exercise restraining or directing influence over, to
reduce the incidence or severity of, especially to harmless levels." In
other words, elimination of snow and ice during a snow fight is not the ultimate
goal. Your goal is to get the priority routes or delivery routes opened up as
soon as possible.
Anti-icing. "Anti" means before. Therefore, anti-icing literally means before icing. This is the action you should take before severe winter weather hits your area. Anti-icing is work that you do to prevent snow and ice from sticking to the pavement surface.
Pre-wetting. A type of anti-icing technique, pre-wetting is a liquid application of an anti-icing chemical. (There also are flake or pellet applications of anti-icer.)
Deicing. This describes the action you take after a severe winter storm has hit your area and traffic has packed the snow down. Deicing loosens the bond between the pavement and the ice. This makes your snow plowing efforts more effective.
Abrasives. The material you use to improve traction on roadways. Abrasives do not melt snow or ice; they simply help the driver by adding friction to the road surface. Examples of abrasives are cinders (wood chips) and sand.
Melting point. The temperature at which snow and ice become water is its melting point. Certain chemicals, when applied to the roadway, lower the melting point of snow and ice, therefore making them water even when it is below 32°F, which is the normal freezing temperature.