In Lee Smiths April 2014 article on Visual Area Protection, I think there is an error. The diagram indicates that the 20:1 slope is the same as standard three degree VDA. My memory, Lee Smiths original Danger Below MDA? from March 2013, and my math indicate that 34:1 is the same as a three degree slope.
Reference Fred Simonds article Need Datalink? in the May 2014 issue. We first put datalink into our Bonanza about a dozen years ago after being stuck for a few extra days by weather. We had a post-mounted StratoCheetah by Echo Flight that used the Iridium satellite system. It worked reasonably well but was intrusive. Next a panel upgrade included the, then, UPSAT MX-20 with WSI datalink FIS. This is what we still use today in contrast to the XMWX system mentioned as the only available system in the article. There are some differences in the data and presentation, but the WSI receiver provides most of the same information as XM systems I have used.
I just read with great interest your article in the April issue, ATP: Higher Cost Soon.