QUOTE(Piltdown Man @ Aug 3 2007, 01:15 PM)
Here is the UK CAA's answer:
Basically, avoid the buggers! Fortunately there is no "black letter law!" on this subject in the UK which means that like the US, common sense prevails. Always the best option. As for me and thunderstorms, I'm chicken. When in the air I'll miss them by as much seems prudent at the the time and will hold or divert at the destination. When waiting for departure, I'll order a cup of tea just before I do a PA to the freight to inform them as to why we will not be departing for a few minutes. But 25 miles separation does appear to be a bit excessive for all of them - a Kansas "supercell" maybe, but not a European winter squib.
I am right with you on this 110%. I am an absolute panzy when it comes to getting near thunderstorms. They are a force not to be messed with by anybody flying any type of airplane for any type of operation. I have spent several days this past summer over flying to places in and around the mid-west ( Kansas, Oklahoma, Texas, Colorado, etc.) and have had to dodge many of these nasty buggers. The thing to note is that the 20 mile rule is more or less a MINIMUM distance to avoid level 3+ cells. I have seen some this summer that have an overhang that streches out for 50 some odd miles,, and trust me, those can still give you a ride that your pax didn't pay for.
The trickiest parts of summer flying in the midwest, and there are 2 of them, are departing and arriving in thunderstorms, and penetrating a line of thunderstorms. Departing and arriving pose a challenge as often times you are threading a very tight needle between a couple of cells to get into or out of your destination. If it looks as though the door is going to close on us though, we get the hell out of there or we wait a few minutes to take off. No place is this more evident than Denver in the summer. You can usually count on 1 or 2 ground stops between the hours of 3 PM to about 8 PM during the summer months. Bottom line is, and this has been said many times before, it is far better to be on the ground wishing you were flying than flying and wishing that you were on the ground. There will always be people out there in higher places pressuring you to go (Especially if you work for an airline), but the thing to remember is that you are the one in the driver's seat, and if you don't like it, than don't do it.
As for penetrating lines of thunderstorms. It doesn't happen often, but it is usually the most unpleasant ride for your passengers. Really all we can do is take a look at the radar and find the best place to skip through in short order. It gets bumpy, but it usually doesn't last too long. Proper radar usage is also key. Know how to identify attenuation and know not to fly towards the dips in the radar will keep you out of trouble. Other than that, trust your gut. If your gut is in a knot, fly somewhere that will untie it.