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69 Respondents listed the need for symmetrical application and Sample Completed Model the need to follow AEA recommendations as the key restric- The figures here provide an example of running the cost- tions they impose or would impose on spot deicing. benefit model. The key benefits of spot deicing for frost removal were listed as: time savings, fluid savings, cost savings, and reduced Figure 25--Instructions Page: The user is not required to environment impact. enter any information on this page. The page does not change Respondents believe a fluid savings of 30 to 60% could be from user to user. achieved by employing spot deicing in place of conventional Figure 26--Background Page: The user has indicated on methods for frost removal. Percentage savings were seen to this page that (1) a contractor currently conducts standard increase with aircraft size. frost deicing at a remote location following the scheduled Respondents indicated that a spot deicing methodology departure time and (2) the operator will conduct spot frost would be less suitable at lower temperatures (86% indicated deicing at the gate, prior to scheduled departure time. This cat- it would be suitable at 0C or above; only 10% indicated egorizes the scenario as a "scenario C" according to Table 42. suitability at below -25C). The user has also indicated 2,400 frost deicings are conducted There was a general lack of knowledge and acceptance annually (using 400,000 liters of fluid) and spot deicing could among the respondents of the frost polishing methodology be used for 50% of them. The default value of 40% glycol usage for frost. for spot deicing is selected, as is the need to purchase new equipment. Figure 27--Costs Page: The user has estimated the required Cost-Benefit Model costs on the costs page. In this scenario (scenario "C"), equip- The cost-benefit model is a user-friendly tool that can be ment operation and maintenance costs are not required for used by operators to determine if switching from standard to standard deicing, as standard deicing is performed by a con- spot deicing for frost removal is financially advantageous. The tractor. For the same reason, staff, inspector, and cleanup costs model will estimate the annual financial savings, annual glycol per deicing are not required for standard deicing. Contractor savings, and number of years until the initial investment has costs are not required for spot deicing as the operator will be been recouped. doing the operation. Finally, block time costs are not applica- The model was tested for different situations by inputting ble for spot deicing, as it will be done prior to the scheduled various parameter values representing typical and extreme departure time. operations. The model was refined and validated by this Figure 28--Results Page: This page provides the results of the process. The final version of the model may be downloaded at model analysis. It shows there is an annual fixed cost expense the link found at of $68,000 and cost savings of $530 per deicing if spot deicing Display.asp?ProjectID=122. for frost is implemented. The operator will save $568,000 and When applied to typical airport conditions, the model out- prevent 120,000 liters of fluid from entering the environment put clearly shows the value of implementing spot deicing. In annually by implementing spot deicing. The initial investment many cases, the financial outlay to implement spot deicing for required (setup costs and capital costs) will be recouped in the frost removal can be recouped in a year or two. second year. INSTRUCTIONS Welcome to the spot deicing for frost cost-benefit model. This model will calculate the number of years it will take to breakeven from the initial investment required to implement spot deicing. Instructions: Fill in all cells that are shaded blue, except those where "not applicable" is indicated. When you have filled in all cells on a page, follow the instructions that appear in red at the bottom of the page. Further comments/instructions are provided in some cells. These comments/instructions are indicated by red triangles that appear in the upper right corner of the cell and can be seen by hovering over the cell. Disclaimer: This model has been prepared by APS Aviation Inc. for the Transportation Research Board. The model makes several assumptions that may not be accurate in every business and/or operational environment. The user is recommended to conduct further analysis if required. To begin, go to the next page (Background) Figure 25. Sample instructions page.