HOW TO STORE THEM

While the current pandemic has stressed all forms of transport, the airline industry has experienced the most drastic effects, placing large numbers of aircraft out of service in a relatively short time frame. During the course of this blog, we'll study the techniques used to store commercial and private aircraft and prepare them to fly another day.

With COVID-19 slashing the demand for air travel, a number of aircraft have been sent to storage for an indefinite period of time. While many planes will be returned to service as the demand for air travel returns, others will remain in storage until market conditions return to pre-pandemic levels. Perhaps the most important factor governing long-term parking of a plane is the weather. Continuous exposure to freezing temperatures can damage tires, while moisture in the air can cause corrosion. Because of this, many aircraft are stored in site with a dry climate and low amounts of precipitation. Often key parts such as engines and batteries are removed, which makes the plane both easier and cheaper to store. However, the disadvantage of detached storage is it usually takes several weeks in order to get an aircraft fully operational.

Speaking of engines, rust is perhaps the greatest hazard during storage. Aircraft engines are designed with the concept of regular use and any deviation requires a heightened state of maintenance. Engines running for only short or infrequent periods are subject to rust as a result of water condensation from extended storage. For a long storage cycle, preservative oils must be put on various parts of the engines to prevent corrosion. These oils offer a high degree of protection and are more appropriate to such use than engine operating oils. An additional means of engine protection is pickeling, in which the engines are treated with a chemical solution with desiccant bags placed in the engine inlets to avert any damage. Fuselage openings should be covered with a special tape or screen to keep insects and small animals out of the plane's interior. The engines should be protected against bird and insect nests, as these can play havoc with their smooth operation. In a short-term situation, engines should be idled for 15-20 minutes on a weekly basis to vaporize any moisture which may have accumulated in the fuel and oil systems. Auxiliary power units should also be activated on a weekly basis, as well as flight computers and other electronics. Additional aircraft checks involve inspecting interior seats and carpeting for any signs of mildew, as well as fuel lines for any water buildup which can cause bacterial growth. Rudder and other control surfaces should be powered and moved every three months to ensure smooth application. Also, the plane's wheels should be moved one-third of a turn in order to prevent flat spots on the tires. Electrical systems should be tested every two weeks.

With current airline traffic at about one third of pre-pandemic levels, the problem of aircraft storage has become one of global proportions. The solutions are dependent upon where the hubs are located, the type of aircraft, as well as the engineering capacity to both mothball the aircraft and then prepare them for service, once the crisis is over. Economics dictate a jetliner should be used as much as possible, with most planes spending a minimal amount of time on the ground at the major global hub airports, such as JFK and Heathrow. Because of this, global hubs lack the space necessary to park mothballed aircraft. Some airlines have used dedicated storage facilities at closed military air bases. Both Delta and Southwest airlines currently store about 50 planes each at the former George Air Force Base, in Victorville, California. Some airlines are able to park a small number of planes at their respective hubs, such as United parking some 40 aircraft at IAH airport in Houston. While hub storage is the most convenient in terms of placing an aircraft back in service, such space tends to be more expensive than aircraft stored in out-of-the-way places. Mobile, Alabama ( where Airbus has a factory) provides storage for American's A321 and Boeing 777 aircraft. Roswell, New Mexico boasts both the most famous and largest aircraft boneyards, storing Boeing 737, 757, 767 and 777 planes. This former USAF base offers the most storage space of any site in use. European airlines have limited options, with many partitioning hubs in order to store aircraft out of service, while placing them at a number of smaller airports.

The current storage crisis has also placed a renewed emphasis on the use of airplane hangars. There are a number of factors governing the use of airplane hangars, which are applicable to both private and commercial aircraft. There are several issues to take into consideration with regard to aircraft storage such as proximity to the home airport (hub), local weather conditions, whether the aircraft is used for private or commercial use, how often the plane is flown, the cost of hangar space, as well as the choice between shared space or a private hangar. Aircraft owners should assess the relative importance of each factor before making a decision on storage. Fortunately, there are many options for hangaring aircraft. An outdoor tie-down, while not a hangar per se, may be feasible in areas where the risk of weather damage is low. Tying down an aircraft reduces the risk of damage from strong winds at a much lower cost than hangaring. However, you should keep in mind that aircraft exposed to the elements will experience more wear and tear, ultimately incurring higher maintenance costs. Another storage option is the shared hangar, in which multiple aircraft are parked in a single hangar. The cost of a shared hangar is relatively low with a number of contracts offering maintenance services. Shared hangars also have their drawbacks, with the hangar owner attempting to store as many aircraft as possible in a given hangar, increasing the risk of both aircraft damage and internal contact between aircraft when an operator needs to move their plane. Private rented hangars provide the maximum protection for a plane with minimal risk of damage. Though this comes at a price, since individual hangaring is the most costly form of plane storage. Private hangars may also be difficult to find. Home hangars are useful when the owner/pilot lives adjacent to the airport. Such hangars are attached to their home, as with a car garage. While not a commonly available option, home hangars are a convenient way to protect aircraft, as well as constructed and cost-effective. Some aircraft owners or operators may choose to build their own hangar, when the conditions present themselves. Hangars range from small structures housing a few planes to spacious facilities built by commercial contractors. Some of the more common structures are shade structures, T hangars, simple storage hangars and maintenance hangars. Shade structures are in essence a roof supported by beams which provide protection from the elements. They are cost-effective and a good option for people who use their aircraft frequently and are suitable for locales with mild weather. T hangers, formed to the letter T, are designed to store a single aircraft. Though they provide full protection from the elements, their primary drawback is inadequate space to perform maintenance. Simple-storage hangars offer full protection from the elements, as with T hangers, with additional space to store a plane along with necessary tools and materials. Maintenance hangars provide room for aircraft storage, as well as tools and materials with the added advantage of allowing plenty of room to move the plane, as well as perform maintenance.

While the cost of storing an aircraft may vary according to the type of hangar employed, another consideration is worth mentioning-insurance costs. How, when and where an aircraft is stored affects the risks it may incur. If the aircraft is protected individually in a secure, indoor hangar, it is less likely to sustain damage, with the reduction in the insurance premium offsetting a major portion of the hangar costs.