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OCR for page 7
7 3. Use of heated Type II and IV fluids as an overspray to 25. Development and implementation of non-glycol or support the use of a more dilute first-step deicing fluid. reduced glycol de/anti-icing fluids. 4. Reduction of fluid buffer for fluids applied before the 26. Use of ice-phobic or hydrophobic coatings to protect start of precipitation, to prevent bonding of frozen pre- aircraft surfaces from adhering contamination. cipitation to the aircraft surface. 27. Use of weather forecasting tools for better identification 5. Development of means of determining de/anti-icing fluid and planning of deicing-related events. failure (adherence to surface) as opposed to identifying 28. Use of forced air assist for applying de/anti-icing fluids. failure by visual indications. 29. Use of infrared deicing technology. 6. Use of Allied Signal Contaminant/Fluid Integrity Mea- 30. Use of spray-and-go deicing procedures. suring System (C/FIMS) to indicate fluid condition and 31. Use of threshold deicing procedures. contamination on aircraft surfaces. 32. Use of spot deicing for frost. 7. Use remote ice detection sensors to scan aircraft critical 33. Increased use of anti-icing fluid dilutions. surfaces just before entering the departure runway. 34. Use of snow/leaf blowers to remove dry contamination. 8. Use of the Intertechnique Ice Detection Evaluation System (IDES) system to detect ice adherence and fluid condition Elimination of Items with on aircraft surfaces. Low Potential for Success 9. Use of warmed fuel to protect wings against precipitation and frost contamination. Following the development of the preliminary list of poten- 10. Use of a mobile infrared system to deice aircraft. tial de/anti-icing optimization technologies and procedures in 11. Use of Type III fluids as a replacement for Type I fluid in the previous section, an analysis was performed to identify those one-step de/anti-icing operations. technologies and procedures offering the greatest promise. This 12. Development and publication of holdover time guidelines evaluation resulted in the elimination of a number of items for heated Type III fluid. because of technical, operational, or environmental short- 13. Documentation of guidelines to ensure that adequate comings, as described in Table 3. quality control checks are conducted on the fluids and on In addition to the items in Table 3, several items of simi- deicing procedures. lar nature were combined under generic titles. For example, 14. Implementation and monitoring of quality control checks Item 6 from the preliminary list, Use of Allied Signal Conta- and operational deicing procedures at airports. minant/Fluid Integrity System (C/FIMS) to indicate fluid con- 15. Determination of optimum spray equipment and tech- dition and contamination on aircraft surfaces and Item 8, Use nique to reduce the shearing effect associated with spraying of the Intertechnique Ice Detection Evaluation System (IDES) Type II/IV fluid. system to detect ice adherence and fluid condition on aircraft 16. Implementation of National Center for Atmospheric surfaces, were combined under the title, Point detection sen- Research (NCAR) Hotplate at airports to provide pilots sors to indicate fluid condition and contamination on aircraft with real-time snow intensity information. surfaces. This reduced the number of technologies and proce- 17. Development of a simulation model to evaluate wing dures for further review, as well as eliminated commercial and exposure to wind and snow catch associated with the use competitive issues related to technologies of similar nature. of different runways. 18. Reduction of delays at the deicing pad following comple- Development of Final List of Technologies tion of the anti-icing application through documentation and Procedures of best practices. 19. Protection of holdover time as opposed to noise abatement Following the activities described in the previous section, when assigning departure runways during deicing events. the following final list of 18 de/anti-icing optimization tech- 20. Protection of holdover time as opposed to noise abate- nologies and procedures in alphabetical order was developed: ment when assigning departure runways during snow- storm events. 1. Blowers and/or other mechanical means to remove dry 21. Implementation of D-Ice A/S all weather holdover time contamination: leaf blowers, brooms, scrapers, etc., to determination system at airports to provide pilots with remove dry contamination prior to de/anti-icing opera- deicing decision support. tion (if applicable); 22. Use of onboard or ground-based lasers to deice aircraft. 2. Deicing-only fluid buffer reduction: "Deicing-only" 23. Use of Tempered Steam as a non-glycol gate deicing or conditions exist when an aircraft is not exposed to a pre-deicing tool. period of active precipitation (i.e., overnight precipitation 24. Use of Tempered Steam as an engine deicing tool. that has ceased by the time of departure). The fluid freeze-

OCR for page 7
8 Table 3. Elimination of Items from the preliminary list. # Item from Preliminary List Reason for Elimination Use of heated Type II and IV fluids as an overspray May require development of 3 to support the use of a more dilute first-step deicing additional set of holdover time values fluid for heated fluids Development of means of determining de/anti-icing Doesn't offer significant 5 fluid failure (adhere to surface) as opposed to environmental enhancement identifying failure by visual indications Doesn't offer significant Use of warmed fuel to protect wings against 9 environmental or operational precipitation and frost contamination enhancement Development and publication of holdover time Doesn't offer significant 12 guidelines for heated Type III fluid environmental enhancement Documentation of guidelines to ensure that Doesn't offer significant 13 adequate quality control checks are conducted on environmental enhancement the fluids and on deicing procedures Implementation and monitoring of quality control Doesn't offer significant 14 checks and operational deicing procedures at environmental enhancement airports Determination of optimum spray equipment and Doesn't offer significant 15 technique to reduce the shearing effect associated environmental enhancement with spraying Type II/IV fluid Development of a simulation model to evaluate wing Doesn't offer significant 17 exposure to wind and snow catch associated with environmental enhancement the use of different runways Reduction of delays at the deicing pad following Doesn't offer significant 18 completion of the anti-icing application through environmental enhancement documentation of best practices Protection of holdover time as opposed to noise Little flexibility is available in the 19 abatement when assigning departure runways process of assigning runways during during deicing events deicing conditions Protection of holdover time as opposed to noise Little chance of success and limited 20 abatement when assigning departure runways environmental enhancement during snowstorm events Use of onboard or ground-based lasers to deice Technological and implementation 22 aircraft challenges Use of ice-phobic or hydrophobic coatings to protect Technological and operational 26 aircraft surfaces from adhering contamination challenges point buffer could be reduced further in these conditions (for example, this procedure would be useful prior to a to limit glycol dispensed; freezing rain event); 3. First-step deicing fluid buffer reduction: Current indus- 5. Forced air used to remove contamination: Forced air has try regulations allow for Type I fluid to be sprayed at a been employed effectively by the industry for several years -5.4F (-3C) buffer (freeze point 5.4F or 3C above to blow off dry contamination prior to de/anti-icing; ambient temperature) when used as a first-step deicing 6. Implementation of holdover time determination sys- fluid (hot water can also be employed down to 26.6F). tems: Airport systems, such as D-Ice A/S Deicing Infor- Testing has indicated that this buffer could be further mation System and NCAR Checktime, which measure reduced; meteorological parameters at airport sites for use in 4. Fluids applied before the start of precipitation to prevent scientific computations to enhance the accuracy of fluid bonding: Pre-treating of aircraft surfaces with de/anti- holdover times, thus facilitating better de/anti-icing fluid icing fluid to protect surfaces against the adherence of ice selection;