hi, I have done several de-ices on
VB.
The best test for ice is to, when you walk up the front stairs, rub the fuse on the aft left side of the door. If no ice, no de-ice procedure needed, if ice, then it is needed.
Also, I have found ice will start on the ib trailing edge first, so, if over about 5 foot tall, you will beable to reach theupper side and feel if ice.
Done bother about all the jargon and rubbish with temps etc. If there is ice on the wing, you will see it. Underside is allowed up to 1/8 inch, which, believe me, you will notice. Basically nothing on the top at all.
Takes about 20 mins to de-ice, so not hard to do. If anyone is in doubt, just do it. simple.
See ya