The 737NG can be CAT IIIb certified. However most are not as they do not have the required servo channels, especially the rudder servo installed.
We do not require a take off alternate as long as the weather is CAT IIIa, we do fly CAT IIIb/CAT IIIa single engine approved 737 700 and 800s.
Last edited by Denti; 29th August 2013 at 11:24.