Ice-bore re your comments:- “As an example, you may wish to check the Maintenance Manual of the aircraft you operate, in order to establish whether the fluid mentioned earlier in this thread has been certified by the aircraft manufacturer.”
One of my points is that fluids are not ‘certificated'; the regulatory authorities take no responsibility. Thus the maintenance manuals may only clear the fluid on the basis that it is non corrosive and does not damage seals, structure, etc. This was the case for several ‘British’ aircraft before aerodynamic tests were undertaken.
“With regard to point 2, it would be the responsibility of the aircraft manufacturer to establish whether a fluid is ‘aerodynamically’ acceptable, prior to use on a particular aircraft type.”
It would be logical to assume this, but there are no regulations that compel them to act. However, several, if not most manufacturers have acted very responsibly after operational problems were identified. Those who conducted aerodynamic tests encountered a range of problems with varying severity, where warranted, changes or special procedures have been published.
Re the types of fluid; good or poor characteristics.
Beware renaming and type categorisation, as these can be misleading; remember that your service provider or airline management deal with sales representatives. An overview of the fluids can be gained by checking the technical specifications of several types; the fluid manufactures have these from SAE etc, and should (reluctantly) give you a copy. The type spec will give details of the viscosity and dry out characteristics that can be compared and then an optimum fluid chosen to suit specific aircraft.
Re cost.
Many ‘de-icers’ over spray the thicker (T2+ and T4) fluids, some less well trained operatives may believe that “more the better” which clearly is incorrect; see the AEA document. A rough guide is that the anti-icing layer should be approx 1 mm thick (1 ltr fluid per sq meter) thus, the crew by being aware of the area of the surface to be coated can estimate the fluid amount (wing, +tail, +fuselage area in sq m = ltr). Of course, for de-icing the aircraft use as much fluid as is required.