Jammedstab,
Lets try and clear some of this up.
Firstly ATC units trigger LVP's depending on Vis and Cloud base to better assure both take off and approaches. The trigger depends on differing National criteria but is typically less than 200ft cloud base or 600m for Europe. A low vis takeoff is less than 400m by definition. ATC are reluctant to give LVP if above these trigger values for one reason.....the effect on flow rate. (Money !)
I have on several occasions asked for LVP with cloud just above or on 200ft base with the answer being sorry no. It is totally unacceptable to shoot a practice Autoland to get under the 200ft if no LVP. There is a reason you have a published DA !
Ironically practice Autolands should only be carried out on a good clear day. A practice autoland with no LVP is an experiment every time. What is regularly overlooked by crews is the need to only practice autolands on cat2/3 approved ILS's. A Cat1 ILS is only calibrated to 200ft. Anything lower and an autoland approach is a leap into the unknown
In you're question, if you have a low fuel situation then you can declare a Mayday and im confident ATC would then give you the LVP assurance
Last edited by 8che; 12th Mar 2013 at 06:47.