Has anyone ever heard of a particular wing design which makes it less suceptible to in-flight icing ? Is it possible to design a wing to make it less likely to pick up ice in flight? Any guys out there, please share your thoughts?
In particular I'm curious about the DC-8 wing if there are any knowledgable pilots on-line. Also any studies or papers written on the subject will be appreciated! The flight manuals are sorely lacking in detailed explainations.
Thanks in advance.
Vito

 

Super-critical wing, found on more "efficient" designed aircraft, ie mooney's, commanche's, columbia's, are more adversely affected by ice than say that big fat wing on a cherokee 6, navajo's, caravans, etc... The only designed wings that prevent ice better than others is turbine aircraft, with heated leading edges. Assuming they are turned on. Tail icing is really more important than the actual wing ice, which tends to be over-looked and forgotten about by most pilots. Tail-stalls are very serious events, and usually come before the wing stops flying in every case.

As far as information, the fed's have plenty of Icing info through advisory circulars, and video's etc.... As far as the DC-8, I have no idea. It is a large aircraft, so I would put money that it does fine in most moderate icing situations, but no airplane does well with accumulation prior to take-off

 

heated leading edges wouldnt typically be used as anti ice would they? if it were to be used that way, wouldnt the water droplets just travel to the backside of the wing and re-freeze, where by the pilots would then not be able to de-ice the wing.

 

No, heated leading edges are considered anti ice. They don't allow the build up of it in the first place.

One of the things that would prevent the backside issue that you describe would be the laminar flow over the wing. Ice builds up at the stagnation point of a wing. At that point there is no airflow and the ice is allowed to build up unmolested. As the ice builds up, the stagnation point moves forward and increases in size.

Boots, on the other hand, can cause exactly what you describe if not designed properly (I would imagine heated edges may be in the same situation). One only need look at the early ATRs for an example of this.

 

my only experience with heated leading edges, was with the P-3 and we did not touch the wing heat until there was 1/2 inch of ice accumulated. It was always explained to me that if we used it as anti-ice the freezing rain would just travel to the ailerons/flaps and collect in the crevices and hinder control surface movement.

 

Both the CRJ and the Citation Encore the heated leading edge is considered "anti-ice"... I've never seen a lot of water run back on either aircraft unless there was ice buildup before we turned them on and we melted it off. Usually it looks like it hits and evaporates.

When talking about aerodynamics, some manufacturers build aircraft that have "aerodynamic" deice/anti-ice. For example, the CRJ doesn't require the wing heat to be on above 230 KIAS. Also the CRJ doesn't have tail deice or anti-ice.

 

Yes, the Gulfstream G-150 has a very unique wing and doesn't readily pick up ice, however, in order to obtain certification for known icing, the company was required to put boots on the wings. They paint them silver to look like it doesn't have boots.

Some aircraft don't require any form of anti-ice on the tail, like the Dassault Falcon 20. The design and angle of the tail make it unlikely it will pick up any significant amount of ice.

 

Yea, the C-17 doesn't have any tail anti (or de)- ice at all. I've always wondered why. In the t-1 tail icing was a huge concern. I've never seen ice at cruise for more than a very short time, so since most ice is encountered on approach or departure and the TAT at those altitudes is high enough, you don't need it?

 

The CRJ doesn't have tail A/I either. They demonstrated that it would fly OK with a full load of ice on the tail.

 

737 = no tail anti-ice either