Icing and Storm Information
This topic shows you how to view icing and storm information on the map and how you can them when building a flight plan.
We estimate that this will take 3 minutes to complete.
Icing and Storm
The Icing and Storm check boxes display icing and storm information on the map.
View Icing and Storm Data on the Map
There are 3 icing options: light, moderate and heavy. Icing displays as the light blue to dark blue color on the Map. Select the Icing checkbox and choose the intensity level to display icing on the map. Icing is only displayed for flight level 280 or below. If a planner chooses a higher flight level, icing will not be displayed. Icing is measured in PPI (percent power increase): Light (0.0 - 0.1), Medium (0.11 - 0.4) and Heavy (0.4 and above). Right-click on the icing display to view information on the icing levels.
icing display on the map
right-click to view information
Select the Storm checkbox to display the storm information on the map measured in vertical velocity. Thunderstorm vertical velocity indicates the intensity of the storm. For example, hail does not appear unless the vertical velocity is above a certain value. It is one value per latitude/longitude and not a millibar based. Thunderstorm Tops indicates the height of the storm, Tops is displayed in the right corner or on-screen if a user right clicks on the area (see screenshots below). NFP outputs data in hundred feet. Thunderstorm displays in the light green to dark green color on the Map.
storm display on the map
right-click to view information
Icing and Storm Avoidance
Fields in the FOMS 220 menu and Aircraft Characteristics menu allow you to enter icing and thunderstorm avoidance parameters.
FOMS 220 Menu
Aircraft Characteristics Menu
You can set these parameters (except for Icing Acft Category) in the FOMS 170 menu. If the parameters are set in the FOMS 170 menu they apply to all aircraft but are overwritten if set in the FOMS 220 menu or Aircraft Characteristics menu for a particular aircraft.
Icing PPI = Icing Percent Power Increase (0.0 – 2.0)
Acft Ice Cat = Icing PPI aircraft category (L = light / M = medium / H = heavy). If this field is blank, the NFP system looks at the Item 9 setting (wake turbulence category).
Vert Velocity = Vertical velocity in meters/second
Fly above by / Fly over Tops = Allow flight above thunderstorm by this value in hundreds of feet
Apply Ice Penalty (ppi) for ETPs (FOMS 231)
If a PPI value (percent power increase) between 0.0 and 2.0 is entered in FOMS 231 for an ETP scenario, NFP will only apply the icing penalty on the route section with PPI forecast above this value.
This only works when icing penalties for either airframe or engine anti-ice are set to “T” (total). If set to any other option, you will get the message shown below:
The ETP station fields are green when this feature is enabled.
FOMS 170 parameter – Default ETP Ice
Options are A (auto), Y (yes), and N (no). If blank, same behavior as A. If set to A, ETP fields are green. This means that using TEL winds and having Aircraft Characteristics and/or FOMS170 configured properly allows NFP to apply icing penalties for ETPs if the PPI values for the icing area(s) encountered between ETP point and ETP alternates exceed the value entered. If set to Y, ETP fields are blue if icing penalties exist in FOMS 231 for the ETP policy used. When blue, the NFP system calculates icing penalties regardless of whether an icing area is present or not between ETP point and ETP alternates. If set to N, no icing penalties are applied.
ETP Scenarios - Web FOMS 231
Web FOMS 231 is available from the NFP Database screen accessible through the Maintenance screen. You can use this screen instead of the traditional FOMS 231 screen.
MEL Penalty - Ice
This new MEL penalty allows NFP to avoid areas of icing with PPI values greater than the value entered in FOMS 428.
Effect = Effect type applied (ICE)
Value = Icing PPI (percent power increase) value (0.0 – 2.0)
When applied to an aircraft, users will see MEL in the info screen.