To ZeroZero and Bafanguy:
Thanks for the information. I have refed Aim chapt 2. The scenarion goes like this.
You get ATis and rvr is 2400 there are no CLL and the markings are obscured (i do have the required 15%), however the question is. May I begin the approach since the RVR is below 4000? (there are marking they are just under 4" of snow and can not be seen.????)
Baf,
The back of a jep page has much useful and at times regulatory info for part 121. However by and large that info is for 91 ops. 121 is regulated primarly by the op spec as far as Alternate criteria, lower than standard takeoff mins (whether hi-mins or not), landing mins as far as requirments for 1800 rvr or cat 2 and 3 ops and NPA's. So even though it says for takeoff mins on the back of the jep page 2400rvr, since my op specs guide me, and if i have CLL i may depart with 1000 rvr (other restrictions apply). my ops specs say i can always reduce as long as standard is published (5000 rvr twins, 2400 rvr 4 engines). Where this rule gets you is if a ceiling is published, then that becomes a limiting factor for takeoff mins. or if the Jep says na for filing as an alternate that must be respected.
hope that helps, and thanks for your replys
vm