Originally Posted by
Escape Path
I wasn't taught this on the line (wouldn't rely too much on it either on line flights for the reasons given above regarding accuracy) but A320 FCTM has this formula for "assessment of vertical expansion of a storm cell": Height (ft) = distance (NM) x tilt (degrees) x 100
I use the same and it's very easy to apply. Formula at first sight looks complicated IMHO but it's actually simple maths. Eg: You set -2 degrees at 40Nm on your ND the center of the beam will be at 2*4 = 8000 feet. All you have to do is to multiple your tilt with your range and add 2 zeros. But if you want to know the cloud top ( assuming there is enough water to appear on the radar) you need to take into consideration the beam width which is about 3 degrees: 3.5 degrees on the WXR-2100 weather radar. So for example if you set your tilt at 3 degrees down, the beam covers actually up to -1.25 degrees down and down to -4.75 degrees.
To be more precise the formula should be: Beam width ( in feet) = (Distance in NM + ''00'') *3.5.
The formula and what I explained above is explained in the ''WXR-2100 Multiscan radar manual.'' Very interesting. If you guys are interested PM me and I can email it to you.