Guest

De-icing

Thu Sep 27, 2001 8:24 am

When is the window/nacelle/wing anti-ice used?
 
OPNLguy
Posts: 11191
Joined: Tue Jun 15, 1999 11:29 am

RE: De-icing

Thu Sep 27, 2001 8:43 am

Windshield heat (electrical) is on all the time in-flight, even in clear-of-cloud conditions. Doing so keeps the windshield more pliable (and not brittle) which comes in really handy in the event a bird strike should occur.

Engine, wing, and nacelle A/I (pnuematic) is operated only when temperature and moisture conditions exist.
ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.
 
Metwrench
Posts: 715
Joined: Fri Aug 17, 2001 11:25 am

RE: De-icing

Thu Sep 27, 2001 2:15 pm

Let's have a short class.

De-ice is a system that sheds ice after accumulation.

Anti-ice is a system that prevents ice from forming in first place.

Pnuematic wing de-icers fall in this catagory, they don't function properaly untill a sufficient amount of ice has built up on the leading edges. If the de-ice boots are inflated too early the ice will have an elastic property that will prevent it from shedding.

Some aircraft utilize engine bleed air that directs hot air onto windscreens to melt ice away, this is also a de-ice system. Some aircraft have an isoprophol alcohol system that sprays this medium on the windscreen. Also a de-ice system, removing the ice after it has accumulated.

Some aircraft utilize anti-ice systems, this theoretically prevents ice from building up in the first place.

Electric windscreens for example, bleed air heated airfoil leading edges also.

In the case of engine inlets, never turn on engine inlet heat before engine igniters are actuated. Why, if ice builds up on the engine inlets and you turn on the anti-ice it will melt and get sucked into the engine. What happens when you throw a bucket of water on a camp fire, it goes out. That's a bad thing at 30,000 feet. If the ignitors are turned on first you have an ignition source to re-light that fire.

Who is online

Users browsing this forum: kengo and 1 guest

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos