airbus_28

I said this in the other thread but it got lost.Slat 4 was identified as being the most critical area of icing on the wing. The criticality is a measure of susceptibility to icing and also the impact of icing on the overall handling qualities (HQ) of the aircraft and in some cases the functionality of a part. An analysis is performed during the design and then the prototype aircraft is fitted with ice shapes and a series of HQ flights are performed. This will verify (or help refine) the design decisions. Once these tests are complete the aircraft carries out a natural icing flight test campaign (usually involves flying into storms if this happens to coincide with summer). This campaign will show how ice naturally forms over the wing and so the verification cycle would be more or less complete.In an ideal world the manufacturer would rather not de-ice the wing (it's all additional weight) so when anti-ice systems are found to be required they are only fitted where it is necessary for safe handling of the aircraft. Given the temperature of bleed air it is a safety risk in itself and to protect against that you end up adding even more weight.Andy

Hi Frederik,This isn't my area but I can answer your question to a point.Slat 4 was identified as being the most critical area of icing on the wing. The criticality is a measure of susceptibility to icing and also the impact of icing on the overall handling qualities (HQ) of the aircraft and in some cases the functionality of a part. An analysis is performed during the design and then the prototype aircraft is fitted with ice shapes and a series of HQ flights are performed. This will verify (or help refine) the design decisions. Once these tests are complete the aircraft carries out a natural icing flight test campaign (usually involves flying into storms if this happens to coincide with summer). This campaign will show how ice naturally forms over the wing and so the verification cycle would be more or less complete.In an ideal world the manufacturer would rather not de-ice the wing (it's all additional weight) so when anti-ice systems are found to be required they are only fitted where it is necessary for safe handling of the aircraft. Given the temperature of bleed air it is a safety risk in itself and to protect against that you end up adding even more weight.Martin, The design team for the anti-ice system is German (and part UK), so you can blame them if you think it's "bizzare logic", safe to say with 40+ years of a/c design experience they might have some idea of what they're doing!AndyP.S. to the anti-Airbus posters, it's kinda sad don't you think? Try to be a little more open-minded - my 2 euro cents.