Sweet Taste of Winter
Tony Vasko reminisces about the variety of aircraft deicing techniques and notes how methods have improved over the years
By Tony Vasko
It's already March in the Carolinas and I only had the sweet taste of winter once this year. The sweet taste, of course, is the taste of deicing fluid and Type I at that. Being something of a dinosaur, I have never had to actually apply any of the newer types of deicing/anti-icing juices. When I was last in a bucket, I was spraying what is now dismissed as Type I - only fit for washing off the snow and ice. We didn't call it Type I because back then, there was no Type II or anything other than plain old ethylene glycol. You could use it straight or you could mix it with water. Period.
LIVING THE HIGH LIFE
Working the nozzle in a cloud of steam, I thought I was at the cutting edge and that it couldn't get any better. The nozzle dispensed my choice of water, or straight or mixed fluid that was actually hot. I could carve off great sheets of clear ice that coated the wings, undermine them and then watch them slide off the wing to crash on to the ground. The flow rate from the nozzle was great and there were thousands of gallons of the stuff in the tanks. Best of all, I did not have to mount a ladder, but rode in a bucket at the end of an articulated arm that I could control.
There were a few downers, of course. The steam from the hot water meeting the frigid air billowed around me. I wear eyeglasses and my view of the world was not the clearest what with water, mist, and glycol settling on them. The howling wind blew the spray and freezing rain back in my face and therein became the "Taste of Winter." Still, in contrast with times before, life on the ramp in a howling, freezing rain storm in the 1980s was good. Relatively. Yet, even with that equipment, we could make little headway on the B747. It was not until the wind shifted, heralding the passage of the front that brought this condition that we finally got ahead of the icing.
BROOMS, BRUSHES, AND ROPES
It was only a few years ago, 1957 or so, that we used brooms, brushes, and ropes, and even wing covers to fight the elements. I must be one of the few people who ever had to fit custom-fitted wing covers to an L-1049 Super Constellation. The difficulty of trying to stretch a 50-foot long balloon cloth cover over the wingtip and then down the top of a wing up to the fuselage in snow and high winds has to be experienced to be believed. So does fighting the lashing ropes under the wing. The designers of the covers also never realized that the fuel tanks were serviced from on top of the wing so they left no holes. And, balloon cloth? Do they still make it?
The brooms and brushes were used to reduce the amount of snow on the wings. The piddly little streams of deicing fluid that came out of a garden sprayer were not going to remove much snow. Granted, airplanes were smaller then, but a Bristol Britania and Lockheed L-1649 each had a 150-feet of wing span to deice. You did it while walking on the wing too, not spraying from the safety of a bucket. Buffeted by the wind and looking down at a very hard ramp from high up, your toes would curl inside your work boots and galoshes as if they could dig into the slippery, aluminum surface.
With the slow rate of deicing/anti-icing we had, the idea of "Holdover Times" was laughable. It depended on judgement that the wings were clear enough to allow a takeoff to be made. We were aided by the fact that we had props to blow and keep at least the inboard sections of the wing clean. Truthfully, I feel a lot better with the systems we have now. Holdover times are semi-scientific at least, and based on some good data; however, they still depend on the training, experience, and judgement of ground and flight crew personnel. I prefer they err on the side of caution.
HISTORY AND RELIABILITY
Reliability of equipment has greatly improved. The garden and tree sprayers I first used up into the 1960s mostly had one-lung engines with mechanical ignition points. Left outside, they're hard to start. Lots of ether helped and so did strong arms and backs as you pulled at the starter rope. The really good ones had self-rewind — the older ones you had to wrap the rope around the capstan for each pull. Often, you had the feeling the rope was a little too short, and if it was only a bit longer, you could spin that monster up enough to get it going. Solid-state ignition is a true blessing and even my lawn mower starts on the first pull most every time and it's 13 years old.
EVOLUTION OF DEICING TRUCKS
The first deicing trucks I used were lash-ups based on run-down fuel tenders. They were a great improvement and much more reliable than a cart with a tank and a putt-putt engine. Still, they introduced the problem of aircraft damage. Visibility in snow conditions is poor. These trucks had no booms and you worked off of an aero-stand cabled to the top. You had to get in close and there was no communication between the shooter on top to driver in the cab — other than bellowing, or maybe screaming in fear.
The first generation of true deicing trucks were far better. Those with built-in heaters for the fluid were great. Communication also had improved and you could talk directly to the driver through an intercom.
Hot water deicing was often used followed by a coat of the Type I to give it a little staying power. It was common to use a weak mix to deice with in very cold conditions. I did my last tours in the bucket using that equipment. It was still cold, wet, and fatiguing work at its best and downright dangerous at its worst.
These models and their successors are still in use, and last winter I watched a big B777 being deiced by a team of them. I was sitting inside the passenger cabin in my nice, warm seat. I felt for the shooters out there. Chicago in the winter can be a hard place to work. It was there I saw the later viscous anti-icing fluids in use. I can attest that it does last a lot longer than the old "run-off-the wing" Type I. Of course, that has had its effect on the equipment manufacturers who have to produce pumps that don't degrade the viscous quality of these advanced juices.
KEEPING WARM AND DRY
Permanent fixed deicing stations with booms are fun to watch. I first saw them in the 1980s at the old Stapleton Field in Denver. The shooter no longer rode in the boom, but sat in a closed, heated cockpit of his own — raised up so he could get a good view. The arm with its nozzle did the reaching out to the airplane parked between two of these units. The operator, having finished spraying our DC-9 freighter, which was only a moment's work with that equipment, reached down and poured himself a coffee from his Thermos® jug. Nice touch, I thought. No snow in his face either. I wondered if the seniority system had reversed itself. In the old days, the senior types drove the truck with its heater while the juniors sprayed in the open air. I imagine the operator here had seniority as he looked warm and a little smug. His only exposure to the weather came at break and lunch times when he had to emerge into the vast, wintry desert of an aircraft tarmac.
I have no experience with the big gantry affairs
or the infrared deicing barns. These all look great and I have heard good reports.
Anything that produces the main aim, an airplane free of any frozen contamination,
is fine with me — as long as I don't have to go up in the bucket and taste
the sweet taste of winter.