The main concern with wings and flight controls is small disruptions in aerodynamic performance which can have large impacts on lift and stall margin...especially on the 200 without leading edge devices.

The fuselage does not generate lift, so the concern is a little drag and a little weight...the weight of any reasonable snow accumulation would probably be less than the type-IV fluid needed to prevent. If you're within the HOT for whatever conditions exist, you will not have massive sheets of solid ice forming on the fuselage. The motors will be fine.

I'm not worried.

 

That's a pretty moot point. Most crashes have little to do with the aircraft and all to do with the airmen.

 

It was sarcasm. People were saying a CRJ has never crashed due to icing, so why make changes.

 

Get your facts correct. A crj has crashed because of icing during takeoff.

 

Read the above post. It was sarcasm. CRJ pilots were saying fuselage ice has never been a problem before so it never would be. I was applying that logic to another topic to show how silly it is. Also, I am very sorry that I am not aware of every aircraft accident. I must be a terrible pilot not now know the history of a plane I never flew.

 

Wing contamination (not fuselage) and waaaayyyy over rotating. Word is they would have flown if they hadn't yanked the plane off the ground in such a ridiculous manner.

 

What's funny is if you slow rotate the 200, the gear will like double-tap the ground due to the trailing link gear . That gear though will also make an awful landing feel great.

 

Your right in the case of most airliners, the fuselage does not provide lift. But with rear mounted engines, it does provide a great surface to accumulate ice that can then be injested into the engines.

I deiced last year, and if I remember correctly, but I may have it switched with the 700/900, every operator that flew into pit with 200's required type IV on the top of the fuselage as well as on the wings tail if they were getting IV at all. I do remember that it was different between the 200 vs 700/900, which I found odd, and then even airline to airline.


But this whole argument is sort of pointless. You don't get Type IV every single time, only if you need a holdover time longer than what type I can provide.

That is 100% false, about type IV...

Type four is thick compared to type I as it is straight Glycol where as type I is always a Glycol/water mix and the water content is based off of that day's temperature. We would watch the ratio for type one very closely, testing it every crew swap or as conditions changed. If it got out of spec, we would add glycol. If your worried about it getting into an intake, you should be more worried about type I.

And while type IV provides a holdover time, with the right conditions, it won't even make it to the shear point as certain precip will begin breaking it down.

Remember people, Glycol itself has no anti-deicing properties. Glycol is used because it is very very good at carrying and transferring heat. Type IV on the other hand forms a barrier between the snow/ice and surface and then slides off taking the containment with it.

 

My understanding is that the upper fuselage is considered a critical surface on all aircraft that have a "T" tail type design. From obeservation I've noticed other aircraft such as the ERJ 145 with a similar procedure. I believe the air passing around the fuselage will pass back and over the horizontal stabilizer of a T-tail aircraft at high angles of attack attitude. Any frozen precipitation might disturb the airflow and have an affect on the airplanes pitch an stall characteristics. I suppose conventional tail airplanes like most Boeings or Airbuses don't have this issue.
I think the packs being off is just to stop sending glycol vapors into the cabin as the fluid is blown back into the packs. I wouldn't think that would make a big difference as it's going into those intakes anyway and once you turn the packs on its going to do it anyway, perhaps it's not as bad?

 

Might want to call the MFG, on the cornstarch thing. Keith (Iceman) A. contacted one of the MFGs of our approved deice fluids and got the deets. Why do you think the Type IV dries to a chalky dust whereas Type I is almost invisible. By all means, think what you like.....
https://en.wikipedia.org/wiki/Deicing_fluid