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1The objective of ACRP Project 10-01, âOptimizing the Use of Aircraft Deicing and Anti-Icing Fluids,â was to identify pro- cedures and technologies that optimize the use of aircraft de- icing and anti-icing fluids, thus reducing their environmental impact while assuring safe aircraft operations in deicing and anti-icing conditions. The project was intended to produce (1) a description of the application of currently available pro- cedures and technologies to optimize the use of aircraft de- icing and anti-icing fluid (ADAF); (2) validation of the effec- tiveness of promising procedures and technologies; (3) a plan for implementation of these promising procedures and tech- nologies; and (4) recommendations for further study. Phase I: Promising De/Anti-Icing Source Reduction Practices Phase I of the project consisted of a literature review of air- craft ground deicing-related technical reports; deicing prod- uct manufacturer reports; and regulatory, government and industry documentation, guidance material and standards to assist in the identification of technologies and procedures that could potentially optimize the use of aircraft deicing and anti-icing fluids, thus reducing the environmental impact of operations using these products. In addition, an industry focus group was surveyed for inputs on current practices and optimization strategies. The literature review and focus group survey identified a list of 18 optimization technologies and procedures for potential future study. Using the Binary Analysis Decision Model, the optimization technologies and procedures were subjected to a ranking exercise, based on a series of weighed analytical criteria. The analysis resulted in the recommendation of several de/anti-icing optimization technologies and procedures for evaluation in Phase II. This effort is described in Chapter 2 of this report. Appendixes A through G are available at http://apps.trb.org/cmsfeed/TRBNet ProjectDisplay.asp?ProjectID=122. Phase II: Research and Development on Four Selected Topics Based on its review of the results of Phase I, the ACRP Project 10-01 technical panel selected four topics for further research and development in Phase II: 1. Fact Sheets for De/Anti-Icing Optimization; 2. Holdover Time Variance Across an Airfield; 3. Increased Use of Spot Deicing for Aircraft Frost Removal; and 4. Increased Use of Aircraft De/Anti-Icing Fluid Dilutions. Fact Sheets for De/Anti-Icing Optimization Several technologies and procedures identified in Phase I were developed into a set of detailed Fact Sheets for optimiz- ing ADAF use. The format followed for development of the Fact Sheets was similar to that used in ACRP Project 02-02, âManaging Runoff From Aircraft and Airfield Deicing and Anti-Icing Opera- tions.â This enabled inclusion of these Fact Sheets within the overall compendium of Fact Sheets for optimizing ADAF use presented in ACRP Report 14: Deicing Planning Guidelines and Practices for Stormwater Management Systems. The fact sheets include a description of the technology or procedure, imple- mentation considerations, and cost information. The Fact Sheets developed in this project are presented sep- arately from this report. Holdover Time Variance Across an Airfield Holdover time determination systems (HOTDS) measure meteorological parameters at airport sites that are then used to calculate expected fluid holdover times, thus facilitating bet- ter de/anti-icing fluid selection. Task 2 of Phase II examined if a single location precipitation sensor can reliably report C H A P T E R 1 Project Summary
precipitation conditions for the entire airport by measuring precipitation intensity simultaneously at different sites at an airport. Data were collected over two winter seasons, 2007â08 and 2008â09, at four airports during 15 snowstorms. Data collec- tion site separation distances varied from 4,167 ft to 28,500 ft. Data also were collected during lake-effect snowfall to exam- ine its effect. Measured precipitation rates produced between-site differ- ences in holdover time (HOT) ranging from zero to greater than 50%. It was concluded that differences in HOT in the order of 20 to 30% are of potential operational interest, and between-site differences greater than 30% are of definite interest. The longest separation distances showed a considerably higher frequency of occurrence of large between-site differ- ences in HOT. The differences in HOT generated from dif- ferent sites begin to impact operations when the sites are sep- arated by mid-range distances and have a definite impact at long separation distances. There is considerable variance in the snow intensity and HOT values derived from test data and from METAR sources. The results, findings, and conclusions developed in the HOT study are presented in Chapter 3 of this report. Appen- dices A through C are available through links on http://apps. trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=122. Increased Use of Spot Deicing for Aircraft Frost Removal In Task 3 of Phase II, an investigation was conducted to substantiate the spot deicing for frost removal methodology, a procedure used to deice small frost-contaminated spots on aircraft wings in lieu of deicing the entire wings. The objec- tive was to better understand current practices and regulations for this procedure, quantify its potential benefits, identify po- tential obstacles to its use, and provide tools for decision makers to determine whether it is suitable for their operation. This effort encompassed (1) a review of current government and industry regulations, guidance material and standards; (2) a survey of airlines and deicing service providers; (3) the generation of a cost-benefit model; and (4) the design and conduct of experimental tests. A significant number of airport and aircraft operators are still not familiar with this procedure, and training, lack of qualified individuals to make assessments, and asymmetrical application are obstacles to its use. The cost-benefit model and presentation aids prepared in this project give operators tools to assess the benefits of implementing spot deicing for frost removal and consequentially encouraging its use. Guid- ance material for spot deicing for frost removal based on the results of this project will soon be available in SAE ARP 4737. The results, findings, and conclusions developed in the spot deicing study are presented in Chapter 4 of this report. Increased Use of Aircraft De/Anti-Icing Fluid Dilutions In Task 4 of Phase II the use of ADAF dilutions was as- sessed to determine the potential for reductions in the use of glycol for deicing and anti-icing aircraft. The objective was to examine current practices and regu- lations related to the use of fluid dilutions and to document the opportunities, limitations, obstacles and potential bene- fits associated with their usage. This encompassed (1) a re- view of current government and industry regulations, guid- ance material, and standards related the use of fluid dilutions; (2) a survey of airlines and deicing service providers; and (3) the development of a cost-benefit model. The study concluded that the majority of users do not em- ploy ADAF dilutions, despite the facts that (1) adequate reg- ulations and guidelines for their use exist and (2) their use can be shown to be cost beneficial for many operations. This lack of use is likely related to a poor understanding that the finan- cial savings to be gained in many cases much outweigh the ad- ditional costs of introducing dilute fluids into an operation. A cost-benefit model and presentation aids were developed to give operators the tools they need to assess whether imple- menting the use of ADAF dilutions would be beneficial for their operation. The results, findings, and conclusions developed in the study of ADAF dilutions are presented in Chapter 5 of this report. 2