He gives me the following additional information:
- MDH is 400 ft
- Field elevation 781'
- He went missed at 1200'
His concern was the MDA is 1140 but that 781' (Field Elevation) + 400 feet (MDH) is higher! He wanted to know if he could legally fly this approach to the MDA of 1140 and said that the ceiling requirement conflicts with the MDA and calculated MDH & FE figures.
I really haven't thought about looking at the MDH and field elevation to see if they add up to the MDA. Not sure why he did this, but it was a great catch! So we thought...Taking a look at the approach chart, I saw what was happening. There is a little (400-1) designation next to the MDH figure which should be ignored. It is for military operations, but I really cant find any official information on what that means. Do military operations have higher minimums than civil aviation? If he wanted to do the math, he should have used 364 - the figure just to the left of the military minimum figure.
The MDA is also calculated from the TDZE of the runway which is 776 and not 781, so that kind of skewed the calculation even further.
I'm using Jeppesen charts right now and didn't see what he was seeing right away. After figuring it all out, I went back to my Jepps and couldn't even find that military MDH and visibility figure on the charts anywhere. I guess the military are probably bound by some regulation to use the government charts, so Jeppesen probably doesn't even bother with including them on their charts.
With all of the acronyms, its hard to keep MDA, MDH, DH, DA, La-de-da all straight. Frequent review of the charts and analysis of every little notation is important so that you don't get caught off guard in the clouds when workload is high.