I realize there is a separate thread on the big storm, but thought it would be worth a separate thread to explain a bit about ice.....

Last night's schedule was cancelled due to the ice pellets. When we operate in winter weather we generally are able to de-ice and anti-ice the aircraft. The de-ice procedure uses a chemical to remove any contaminants from the aircraft surfaces. Anti-ice uses a separate chemical to prevent re-formation of any contaminants.

We use different chemicals depending on the type of precipitation, and have charts that define the amount of 'holdover time' from time of application until the aircraft has to be re-treated. With snow, light snow, etc. we are generally able to see holdover times of 25 minutes, 40 minutes, etc.....it is all dependent on the rate of precipitation, outside air temperature, etc.

With ice pellets and freezing rain the holdover time is 0 minutes. Essentially, as soon as the application is made, you are not legal to takeoff. If last nights storm had just been snow, the operations would have been able to continue. As soon as it turned to ice......it was a matter of shutting down the system, and gearing for a re-start today.

It's frustrating on everyone. I would have preferred to have been typing this from Stockholm today, but get to fly a rescue flight down to Orlando later this afternoon. Keep your chins up, and hope to see 216 of your smiling faces getting off my aircraft later this afternoon in sunny Orlando.

DRW