Cover Image

Not for Sale

View/Hide Left Panel
Click for next page ( 88

The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement

Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 87
87 ASSUMPTIONS USED IN THE MODEL This model makes several assumptions about operations, fluid and fluid use that may not apply to every user. Users are encouraged to review the assumptions below to asses whether further analysis if required. 1. If considering a switch to diluted Type I and/or Type II/III/IV, the user currently uses Type I ready-to-use and/or Type 1. II/III/IV neat fluid. 2. If a switching to diluted Type I fluid, all Type I fluid used will be diluted to the buffer, even fluid used in the first step of 2. a two step operation. 3. Glycol recovery costs are not achieved by switching to diluted fluids, as they are assessed on the amount of fluid, not 3. glycol, dispensed. 4. There is no distinction between Type II, Type III and Type IV fluid. 5. Inflation / current value of future cash flows are not relevant. 6. Type I concentrate is 100% glycol (for glycol savings calculation). 7. The percentage concentrate of Type I fluid required to achieve a specific fluid freeze point (FFP) is the same for all 7. Type I fluids (the percentages used in the model are the average values of 12 Type I fluids). 8. The default fluid freeze point (FFP) buffer for Type I fluids is Type I FFP Buffer: 10C buffer 8. 10C. The user can modify this to 15C or 20C to the right. 9. The percentage of Type II/III/IV operations that will use neat, 75/25 and 50/50 fluid at each OAT range must be estimated. 9. The values below are the default values and are assumed to be correct unless modified by the user. Temperature Range Neat 75/25 50/50 a) > 0C 0% 50% 50% b) < 0 to -3C 25% 50% 25% c) < -3 to -6C 50% 50% 0% d) < -6 to -10C 75% 25% 0% e) < -10 to -15C 100% 0% 0% f) < -15C 100% 0% 0% Go to the next page (Background) Figure 31. Sample assumptions page. Figure 33--Costs Page: The user has estimated the costs asso- buffer is a financially sound and environmentally advanta- ciated with making a switch to diluted Type I fluid, including geous decision. capital costs, setup costs, fixed annual costs and the price of the Type I concentrated fluid that will be used ($3.00/liter). It Conclusions and Recommendations should be noted that in this scenario, the cost of the concen- trated fluid that will be used is more than the cost of the pre- The conclusions and recommendations resulting from this mix fluid currently being used ($3.00/liter vs. $2.00/liter). study of the use of diluted fluids for de/anti-icing aircraft are Figure 34--Results Page: This page provides the results of the provided in this section. model analysis. It shows that by switching to Type I diluted flu- ids, the user in this scenario will save $1,111,122 annually, will Conclusions prevent 203,307 liters of glycol from entering the environment, and will recoup the initial investment (capital costs and setup A review was conducted of current government and indus- costs) in the second year. try regulations, guidance material, and standards related to the Figure 35--Breakeven Schedule Page: This page shows the use of fluid dilutions. Several important conclusions came out initial investment required to switch to diluted fluid operations of the literature review. will be recouped in year two. Clearly for this operator, switching from a Type I ready-to- Regulations do exist for the use of fluids and their dilutions use fluid to a Type I concentrated fluid blended to a 10C and were deemed to be adequate. (A survey of airline and

OCR for page 87
88 BACKGROUND QUESTIONS - GENERAL 1. Are you considering switching from a Type I ready-to-use fluid to yes 1. a Type I buffer fluid? 2. Are you considering switching from a Type II/III/IV neat fluid only no 2. operation to a Type II/III/IV neat and diluted fluid operation? 3. How will you procure diluted Type II/III/IV fluid? not applicable 4. Do you prefer to complete this analysis using litres or gallons? liters 5. How many operations are conducted per winter season? Type I Fluid Type II/III/IV Fluid a) above 0C 250 not applicable b) below 0C to -3C 500 not applicable c) below -3C to -6C 1,200 not applicable d) below -6C to -10C 1,700 not applicable e) below -10C to -15C 800 not applicable f) below -15C to -20C 450 not applicable g) below -20C to -25C 200 not applicable h) below -25C 25 not applicable All temperatures 5,125 not applicable 6. Average amount of fluid (in liters) used per winter season: 1,500,000 not applicable 7. Price (per litre) of currently used fluid: $2.00 not applicable 8. Glycol (%) in currently used fluid: 55% not applicable This page is complete. Please go to the next page (Costs). Figure 32. Sample background page.

OCR for page 87
89 CAPITAL COSTS - NEW EQUIPMENT a) Cost of new blending trucks/equipment $ 1,000,000 b) Cost of new fluid storage equipment $ 150,000 FIXED COSTS - ONE TIME SETUP COSTS a) Cost to gain in-house approval from all affected branches to proceed $ 2,000 b) Cost to develop, publish and approve new procedures $ 2,000 c) Cost to include new procedures in airline deicing program, get approval $ 5,000 d) Cost to develop training materials $ 10,000 FIXED COSTS - ANNUAL a) Addtitional equipment maintenance costs $ 15,000 b) Additional ground crew training costs employees 55 x cost per employee $ 160 $ 8,800 VARIABLE COSTS Type I a) Price (per liter) of Type I concentrate fluid $ 3.00 Type II/III/IV a) Price (per liter) of Type II/III/IV neat fluid not applicable a) Price (per liter) of Type II/III/IV 75/25 fluid not applicable a) Price (per liter) of Type II/III/IV 50/50 fluid not applicable Please fill in ALL of the empty blue cells above Figure 33. Sample costs page.

OCR for page 87
90 RESULTS Type I Fluid Costs (per winter season) Current ready-to-use operation $3,000,000 Proposed 10C buffer operation $1,865,078 Type II/III/IV Fluid Costs (per winter season) Current neat fluid operation not applicable Proposed diluted fluid operation not applicable Annual Fixed Costs (per winter season) Additional fixed costs related to fluid switch $23,800 Impact of Implementing Fluid Switch (per winter season) Financial Savings $1,111,122 Glycol Savings 203307 liters Initial Investment Required to Switch to Diluted Fluid s Set-up Costs $19,000 Capital Costs $1,150,000 Winter Seasons to Breakeven 2 See next page (Breakeven Schedule) for further details Figure 34. Sample results page. DSPs later confirmed that users also feel that current regu- ter deicing season, cost of fluid, cost of blending equipment, lations are adequate, although several respondents noted and replacement cost of modern deicing equipment. some clarification or elaboration of the regulations could be Of all anti-icing fluid types (Type II/III/IV) and strengths useful.); and (100/0, 75/25, 50/50) available, Type IV 100/0 is used almost Holdover times exist for diluted fluids and are published on exclusively. an annual basis. In the case of Type I fluids, holdover times Ready-to-use fluid is the most commonly used mixture of have been developed with fluids mixed to a 10C buffer. In Type I fluid; Type I fluids mixed to FFP buffers are not com- the case of Type II/III/IV fluids, holdover times have been monly used. developed for 100/0, 75/25, and 50/50 dilutions. Notably, Type II, III or IV fluid mixes are infrequently used for one- the enhancement in holdover time is not significant as a step procedures. result of using richer glycol mixes of Type I fluid nor when A 10C buffer is the most common buffer used for using 100/0 Type II/III/IV fluid rather than 75/25 diluted Type I fluids by operators with proportional blending fluid. Therefore in many cases, glycol usage can be reduced equipment. without holdover times being reduced significantly. Hot water is rarely used for deicing as the first step in a two- step procedure, nor is hot water often used for defrosting A focus group from the deicing industry was surveyed to operations. gather a more thorough and detailed understanding of the Most operations at non-hub airports do not make use of industry's perceptions and current usage of diluted fluids. Key diluted fluids. findings from the survey are: Proportional blending systems to provide deicing fluids at the required buffers are readily achievable, and their costs Deicing and anti-icing fluid use varies considerably depend- can usually be recovered in one or two deicing seasons, ing on aircraft size and precipitation condition. depending upon the amount of deicing fluid sprayed. The top five factors influencing use of fluid dilutions are: Additional training is required for both the deicing fluid storage requirements, prevailing OAT during the win- specialist and the senior deicing specialist on a yearly