The Latest Tech Advances in Aircraft Deicing & Anti-icing GSE?
We are smack dab in the middle of the winter flying season right now, and while there is some evidence of spring in the near future, we’re not out of the woods just yet. This is especially true for flight ops in the northern states and Canada, where they still have many weeks of winter mayhem to account for. Aircraft deicing and the familiar orange hue of deicing fluid will persist for a while.
Aircraft deicing has remained relatively unchanged over the history of its use, which numbers in the decades now. Deicing vehicles preheat propylene glycol deicing fluids to a certain temperature, then begin deicing planes. They spray the aircraft’s surface with deicing fluids or anti-icing fluids, depending on the demand.
Is there any movement towards a new method that doesn’t rely so heavily on fluids? Or maybe adjustments to the deicing process to use less? Let’s find out.
How Do They Deice Airplanes?
First, you need a little background on what exactly is used in the deicing process. Deicing fluid is a generalized term for different kinds of fluids used in the process.
There are four different primary deicing fluids that are commonly used in aviation and aircraft deicers:
- Type I (red-orange)
- Type II (clear or straw-colored)
- Type III (yellow-green)
- Type IV (emerald green)
De-icing uses fluids that are designated Type I-IV, which are made of either ethylene or propylene glycol. De-icing trucks are kept plugged in with heating elements, keeping the Type I between 140°-150° F. The fluid is sprayed at high pressure to make sure all contaminates are blasted clear of the surfaces. De-icing trucks are also sometimes equipped with high-volume, low-pressure air pumps to blast loose snow off of the surfaces, although this is not required. One of the reasons for the blower is to reduce glycol usage and reduce costs (air is much cheaper than de-icing fluid).
Anti-icing units are a different approach altogether. Anti-icing is a pretreatment that is applied in anticipation of icing events to prevent ice from sticking. According to the FAA Advisory Circular (A/C) 120-60A, anti-icing is applied to clean aircraft that are not already contaminated, and the fluid is applied unheated.
The most common fluids used are:
- SAE Type I fluid.
- Concentrates or mixtures of water and SAE Type I fluid.
- Concentrates or mixtures of water and SAE Type II fluid.
- Concentrates of SAE Type III fluid.
- Concentrates or mixtures of water and SAE Type IV fluid.
How Does Aircraft Deicer Work?
Aircraft deicing is a fairly simple process: heat up the fluid (whichever type is best suited for your application. The deicing truck is plugged in, and the heating elements in the tank keep the airplane deicing fluid properly heated.
Ground crews use specially made brooms and scrapers to remove standing snow off of the wings and control surfaces, and then the truck comes along and does its magic. The aircraft surfaces are first blown off with high-volume/low-pressure air (if the truck is equipped for that), and then the warm fluid is sprayed on at high pressure to knock the built-up ice and snow off of the aircraft.
The entire aircraft surface is cleaned to ensure it can fly safely in wintry weather.
What Is Aircraft Deicer Fluid Made Of?
Aircraft deicing fluid is made from Propylene Glycol, which is a food-safe element. Modern deicing fluids are non-toxic, a good departure from yesteryear when aircraft de-icing was far less environmentally friendly. This is a net win for all of aviation and the surrounding communities. The core ingredients are the same in all four types of fluid, but they use various amounts of other agents to increase or decrease viscosity. Each has a specific purpose, and a timetable is added for each fluid type with holdover times.
Hold Over Timetables
The FAA provides a standardized timetable for all HOT, which they release every year prior to the winter flying season. This guidance provides the minute details on everything imaginable, but the table above really lists everything that you need to know for practical purposes.
Type II & IV both contain thickening agents to increase the viscosity of the fluid. They do this to stay on the aircraft longer to absorb and melt off snow and ice. The result is a much higher rotational speed threshold to shear off the fluid built up on the surfaces of the aircraft, but the HOT is far longer. Type II is not generally used in North America, but Type IV is common and affords the highest HOT of them all.
What Are The Future Methods Going To Be?
While modern deicing works remarkably well, they are definitely due for an update. While technology has improved wildly, aircraft deicing technology is still stuck in the 1950s.
Advanced Aircraft Coatings
The most logical solution involves coating the surface of the aircraft with materials that repel water, thereby preventing ice from forming. The European Union has already undertaken one such Project, PHOBIC2ICE.
Aviation icing problems stem from the nature of aluminum surfaces that allow water droplets to stick to the surface easily. Once an initial layer sticks, the ice starts building on itself, and you have a serious issue. But if you are able to keep the ice from ever sticking in the first place, you will never have a buildup of ice. Special coatings to prevent icing seem logical and have a much lower impact than deicing aircraft.
An interesting aside is that the concept for this comes from the lotus flower, which fully repels water and other contaminants due to the texture of the plant.
Electromagnetic Heating Strips
Advanced electromagnetism technology is now making heating strips a reality for aircraft. You know those little strips on the rear window of your Honda Odyssey? It’s like that, but much larger, of course.
But it’s no science fiction; Air Canada is actually the very first carrier to opt in for the system, made by De-Ice, a Boston-based technology firm. The idea is simple enough: create tape strips of electronic heating elements that the pilot controls from the cockpit. It also appears that these will have applications during flight as well as on the ground.
Somewhere in the middle lies a hybrid of these two systems. NEI’s NANOMYTE® SuperAi anti-ice coating is another coating that stymies ice formation on all surfaces it is applied to. But you can add the Ivercon retrofittable electropnuematic deicing system to heat the surface (similar to De-Ice’s system).
The Ivercon system is very light and will last the lifetime of the aircraft it is fitted to. Oh, and it will fit any airfoil. The hybrid approach seems to make the most sense. The best approach is to prevent the ice from ever accumulating rather than trying to remove it once it is there. The cost savings will be immense once these systems are completely ironed out and fully implemented, and it is only a matter of time.
How Greenwood Aerospace Can Help Your Deicing Program
In the meantime, aircraft deicing will remain largely as it has for the past decades: through the use of aircraft deicing trucks and trailers. When it comes time to update your fleet, Greenwood Aerospace will be your trusted partner to facilitate the procurement. We will make sure that you get the best deal, stay within budget, and get exactly what you need to keep your winter flight operations safe and on time.
At Greenwood Aerospace, we provide aerospace, military, and government procurement solutions on a domestic and global scale. We are dedicated to delivering the support you need, minimizing downtime, and providing enduring solutions for all your aerospace and facility-related necessities.