The National Transportation Safety Board has released a Safety Alert regarding inflight icing aboard airplanes and the dangers it poses. Recently, commercial plane crashes have been consuming the news headlines.
Ice-briding as it is referred to can be an extremely serious and dangerous condition for an aircraft. I’ve added a few of the items in the NTSB report below. Please check the report for yourself to see the complete report.
- As little as 1/4 inch of leading-edge ice can increase the stall speed 25 to 40 knots.
- The danger is that some 1/4-inch accumulations have minimum impact and pilots become over confident.
- Sudden departure from controlled flight is possible with only 1/4 inch of leading-edge ice accumulation at normal approach speeds.
- For 60 years, pilots have been taught to wait for a prescribed accumulation of leading-edge ice before activating the deice boots because of the believed threat of ice bridging.
- In theory, ice bridging could occur if the expanding boot pushes the ice into a frozen shape around the expanded boot, thus rendering the boot ineffective at removing ice.
- The Safety Board has no known cases where ice bridging has caused an incident or accident, and has investigated numerous incidents and accidents involving a delayed activation of deice boots.
