Why don't they de-ice planes like a car wash?

Question

Why don't airports de-ice planes right before take off (at the end of the runway).

Have a large setup at the end of the taxiway where each plane gets de-iced second before they get on the runway for departure?

Answer 1

That's one way that it's actually done. Many airports do it exactly that way, especially in severe icing conditions.

The don't use a building like a carwash to do it, they use bucket trucks or cherry pickers but the de-icing operation is done right on the hammer-head immediately prior to departure.

It's not possible to erect a structure that close to the runway for safety reasons, but it's easy to do it with portable deicing equipment.

Answer 2

Ice can easily change the shape of a wing. Some wings are touchy this way; as little as an inch of ice (or less) can cause an aircraft of some types to actually feel like they will loose almost all lift at most throttle settings. The normal type of lift is either converted to drag, or is forced fore-ward or backward until the plane is no longer balanced as some shapes lift at different points along the wing. Unfortunately, there is only so much power available a pilot, so some aircraft actually are forced down by this. New technology exists, however, to augment the normal type of lift put out by engines on SOME planes. Normally, cold does not mean ice. Cold air is usually dry; but when it is wet things go very bad very soon. Usually -50 degree air is very dry and this is not out of the norm at some altitudes (but this is -50* in Fahrenheit). -50* in Celsius is a very cold chill indeed.

Answer 3

Interesting proposal but three problems come to mind. First, the structure they would have to build would be massive and the pilots would be "driving" through it very fast - lots of danger of "clipping off a wing" if you are off by a little bit. Two, Planes are going at around a hundred miles an hour when they take off, the air rushing by decreases the temperature even more on the wing surface - bad if you are trying to deice. Third and most important. the ice needs to be off the plane before the plane starts to take off. This is because ice is very heavy and the buildup of ice adds "size" (area) to the wings. The additional weight on the plane and area on the wing means more drag which hurts the ability of the plane to takeoff.

Answer 4

A car-wash type system for airplanes would have to be huge to accommodate the large commercial jets in service today, but would also waste a lot of the deicer fluid, from overspray and from excessive application.

A human operator directing a stream of heated deicing fluid at the effected parts of the aircraft is a much more efficient way to insure the aircraft is clear of ice and safe to take-off.

Answer 5

It would cost too much money.