This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Issues and Testing of Non-Glycol Aircraft Ground Deicing Fluids
ISSN: 0148-7191, e-ISSN: 2688-3627
Published June 13, 2011 by SAE International in United States
Annotation ability available
Deicing fluids are used to remove and prevent ice formation on aircraft before takeoff. These fluids are essentially composed of water, a freeze point depressant (FPD) usually glycol, a surfactant or wetting agent and a corrosion inhibitor. All commercial fluids are qualified to SAE (Society of Automotive Engineers) specifications, which test for aerodynamic acceptance, anti-icing endurance, corrosion inhibition, material compatibility, fluid stability and environment. However, these tests have been built around a fluid with a glycol FPD. More recently, with environmental pressure, fluids with other FPDs have been developed and qualified. The other FPDs include: acetates and formate salts, sorbitol, and other undisclosed FPDs.
The acetates and formates, which came out in the early 1990s led to suspected corrosion problems. This led to the additional requirement for corrosion tests for non-glycol deicing fluids in paragraph 3.1.1 of AMS1424. This is essentially only a relevant for such a salt based non-glycol fluid.
Next, came a sorbitol, or sugar, based fluid in the early 2000s. As with the formate and acetate salts, it passed all the required tests of AMS1424 including the additional corrosion test. But then in field tests, where the fluid was heated as per usual use, there were problems with foam, sticky and slippery residues. All standard specification laboratory tests are conducted on cold fluids, since this is the worst case for glycol-based fluids, where they are most viscous. However, other FPDs may have the fluid increase in viscosity with heating and evaporation. Following the failed field tests, tests were conducted in the laboratory which showed that when the fluid was heated to high levels of evaporation, the aerodynamic acceptance test was not met and with further evaporation, the fluid solidified. This does not occur with glycol-based fluids since glycol is a liquid. Furthermore, in the lab, mold developed on some exposed fluid left out in a Petri dish.
The FAA has since removed this fluid from their list of qualified fluids in the official FAA Holdover Time Tables . More recently, there have been newer fluids that are non-glycol-based, or have another FPD along with the glycol (low-glycol). These fluids all are qualified at least for aerodynamic performance and anti-icing endurance and two are on the current FAA list of qualified fluids. However, the specification has no tests to address stickiness, solidification or tendency for mold to form. For the foam, a test was added to the specification since this issue was arising equally with glycol-based fluids.
As part of a grant from the FAA, AMIL is developing test protocols to be added to the test specifications to address the new potential issues that may be required of non-glycol fluids before their use on aircraft.
Beyond the corrosion and foam issues for which tests currently exist in the specification, test for aerodynamic acceptance on evaporated heated and sheared fluids, tendency to from mold and slipperiness are proposed.
CitationBeisswenger, A., Laforte, C., and Perron, J., "Issues and Testing of Non-Glycol Aircraft Ground Deicing Fluids," SAE Technical Paper 2011-38-0058, 2011, https://doi.org/10.4271/2011-38-0058.
- FAA “Official FAA Holdover Time Tables, Winter 2010-2011, update N8900.144.” Federal Aviation Administration Washington, DC 57 2010
- SAE International Aerospace Material Specification “Deicing/Anti-Icing Fluid, Aircraft SAE Type I,” SAE Standard AMS1424J Dec. 2009
- Gold, H. Joback, K. Geis, S.W. Maricas, D. Ferguson, L. Corsi, S.R. “Alternative Aircraft Anti-Icing Formulations with Reduced Aquatic Toxicity and Biochemical Oxygen Demand” ACRP 02-01 - 220.127.116.11 Transportation Research Board Washington, DC 12 2010
- Curtis, B.R. “Problems Associated with the Testing of Glycol-Free Aircraft Deicing Fluids” SAE G-12 Meeting 2004 Montreal, Canada
- Beisswenger, A. Gagné, N. Perron, J. “Alternative Aerodynamic Acceptance Testing of Non-Glycol-Based Deicing Fluid” 2004-AB-04 Boeing C-17 Systems Group, Anti-icing Materials International Laboratory Chicoutimi, Quebec 49 2007
- SAE International Aerospace Standard “Standard Test Method for Aerodynamic Acceptance of SAE AMS 1424 and SAE AMS 1428 Aircraft Deicing/Anti-icing Fluids,” SAE Standard AS5900B July 2007
- SAE G12 Fluids Subcommittee “Unconfirmed Minutes of the SAE G12 Fluids Subcommittee Meeting May 22, 1995, Amsterdam, the Netherlands” 1995
- SAE G12 Fluids Subcommittee “Unconfirmed Minutes of the SAE G12 Fluids Subcommittee Meeting May 22 1996 Pittsburgh, PA 1996
- Conkle, H. Kuczek, S. Chauhan, S. Simmons, K. et al. “Environmentally Friendly, Non-Glycol Type I Aircraft Deicing Fluid,” SAE Technical Paper 2003-01-2125 2003 10.4271/2003-01-2125
- Beisswenger, A. Gagné, N. Perron, J. “Aerodynamic Alternative Testing of Low/Non-Glycol-Based Type I Deicing Fluid on a Large Transport Aircraft” 2009-AB-14 Anti-icing Materials International Laboratory Chicoutimi, Quebec 115 2009
- Dyer, K. “Anti-Icing Fluid Residues,” SAE Technical Paper 2007-01-3302 2007 10.4271/2007-01-3302
- SAE International Aerospace Material Specification “Fluid, Aircraft Deicing/Anti-icing, Non-Newtonian (Pseudoplastic), SAE Types II, III, and IV,” SAE Standard AMS1428G Dec. 2010
- Sapienza, R. “Environmentally Benign Anti-icing or Deicing Fluids” U.S. Patent 6,129,857 October 10 2000
- Sapienza, R. Johnson, A. Ricks, W. “Environmentally Benign Anti-icing or Deicing Fluids Employing Triglyceride Processing By-Products” U.S. Patent 6,890,451 B2 May 10 2005
- SAE International Aerospace Recommended Practice “Aircraft Deicing/Anti-icing Methods,” SAE Standard ARP4737H July 2008
- Dawson, P. Hanna, M. Chaput, M. Peters, A. Blais, N. “Aircraft Deicing Fluid Freeze Point Buffer Requirements fo Deicing Only Conditions” Transport Canada TP13478E APS Aviation Inc. Montreal, Quebec 176 1999
- Lally, E. “Viscosity Characteristics of Sprayed Sorbitol Based Aircraft Deicing Fluids” Aerodynamics Working Group of the SAE G12 Fluids Subcomittee Meeting 2004 Pittsburgh, PA
- ASTM American Standard Test Method “Standard Test Methods for Rheological Properties of Non-Newtonian Materials by Rotational (Brookfield type) Viscometer” ASTM D2196-10 2010
- American Standard Test Method “Standard Test Method for Using a Variable Incidence Tribometer (VIT)” 2000
- English, W. “Pedestrian Slip Resistance, How to Measure It and How to Improve It” Second William English, Inc. California 0-9653462-2-4 185 2003
- Harvison, E.J. “Anti-Slip Surfaces” EP Patent 0 676 506 A2 February 14 1991
- Kroes, Gert Jan “ref: Safeway PFS non-skid / your fax message 1998-January-15” 1998
- American National Standards Institute “Standard for the Provision of Slip Resistance on Walking/Working Surfaces” ANSI A1264.2 - 2006 2006
- SAE International “Unconfirmed Minutes of the SAE G-12 Fluids Subcommittee Meeting” Society of Automotive Engineers Berlin 2010