Hi All,

Just doing the Irex course at FTA (Adelaide) but finding Bob's book a great companion when I want to verify something, or set my head straight.

In our course we are using the Jeppesen version of the charts which has been interesting, however on page 5.5 of Irex (July 2013) it says Minimum Safe Altitude, whereas the Jepps and the instructor call this Minimum SECTOR altitude, which under the circumstances makes more sense as the 25nm plate does not necessary have the same altitude available for obstacle free flight in all direction (ie there can be sectors).

Should I assume that MSA can mean both Minimum Safe Altitude as per page 5.5 but also is interchangeable with Minimum Sector Altitude.

Another point of contention between two instructors here, but is brought out as being consistent with with Bob is saying on Page 5.4 is that of Pan Ops 4 charts.

Now once again, using the Jepp Charts, many of the newer charts that have Aircraft Categories (ie A, B, C D and E) still only have "Pan Ops" written on them, instead of the required Pan Ops 4 so it appears that Jeppersen themselves might be at fault here.

Our instructor (like Bob) swore that that was the way to identify them apart from the old type (ie Pan Ops vs Pan Ops 4) but the other instructor (same facility) insisted that that was NOT the way, in the only RELIABLE way was to see if multiple aircraft categories were present was to see if only one vis / alt figure present on the plates instead of multiple figures for different ACFT categories (eg A, B etc).

Now it would appear there are only a couple of original pan ops plates left such as Georgetown, but still many of the plates say Pan ops when they should by definition say Pan ops 4.

If that IS the case, then Jepp (and probably air services) will need to update their plates on the corner of each plate, so unless there is something that I am missing, then it appears Jepp / Air services are at fault. You surely can't have it both ways, as there is conflict with the definition...

Minimum sector altitude is correct. It used to be called minimum safe altitude in the Airservices documents but that has changed to minimum sector altitude. The idea was that minimum safe altitude could sometimes be broken up into sectors, in which case minimum sector altitude was used to refer to each sector. When you come to think of it, minimum sector altitude is a rather odd way to describe a 25 mile circle with no sectors - still quite common. However, the correct term is now minimum sector altitude. Check the definitions and abbreviations in AIP GEN 2.2. I'll make the necessary changes in the next print of the book.

Old and new charts is an argument hardly worth having since you will have trouble finding more than two examples of 'old' charts now.

Bob

Thanks Bob - just wanted to make sure on both counts in case I was missing something!