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Old 7th Feb 2014, 20:37
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AirRabbit
 
Join Date: Apr 2005
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Danger

aterpster I don’t mean to get into a nit-picking exchange of details and, of course, no one should be overly critical of anyone without knowing ALL the facts – and in an airplane accident, there are very few who really do KNOW all the facts. In this specific case, it seems that you want to point at the controllers for not giving more specific instructions – or – that the instructions that were given were not the instructions you think should have been given. Hind-sight is usually better than facing a situation new to you … and, apparently the FAA has previously agreed that some changes in directions/clearances had to be made. As far as I know, those have been made.

Now, with respect to your posts, I can say that, while I’ve never been to Dillingham, it appears that the approach plate for the RNAV (GPS) approach to RWY 19 at the Dillingham Airport, Alaska, shows that the minimum safe altitudes within 30 NM of the ZEDAG intersection – are as follows: from the northwest (282 deg bearing from that intersection) clockwise to the southeast, (102 deg bearing from that intersection) the minimum safe altitude is 4300 ft within 4 NM and is 6300 ft from 4 NM out to 30 NM … and from the southeast (102 deg bearing from ZEDAG) clockwise back around to the northwest (282 deg bearing from ZEDAG), the minimum safe altitude is 5400 ft all the way out to 30 NM. Within the holding pattern (192 degrees inbound and 012 degrees outbound from that intersection, with 5 mile legs) the minimum safe altitude is 4300 feet – BUT in looking at the chart, it could be that, when you get outside of 4NM outbound from ZEDAG and apparently still in the holding pattern (as the holding pattern appears to extend to 5 NM) which would place the airplane 1 NM outside of the 4 NM limit for MSA of 4300 ft. the minimum safe altitude jumps to 6300 feet. (My guess is that when established IN the Holding Pattern, the 4300 ft would provide safe obstacle clearance.) However, it is clear that when established on the final approach course for Runway 19, ON the 192 degree radial after passing ZEDAG, inbound to the runway, on the approach to RWY 19, the minimum safe altitude is 1900 feet until reaching the final approach fix at FIXUV. Once passing that FAF, the minimum descent altitude is 540 feet – unless you desire to circle, in which case, the MDA would be 600 feet. After saying all of the above, if the instruction given to the crew was “…proceed direct to the Initial Approach Fix (IAF) to begin the approach, and to maintain an altitude of 2,000 feet or above…” I would think it would be appropriate to maintain the MSA as indicated on the chart (i.e., 4300 ft. inside of 4 NM and 6300 ft. between 4 and 30 NM), or 2000 feet, which ever was greater, depending on the location of the airplane (and I've been presuming the airplane was essentially north of the airport) and then ... when established on the final approach course inside the FAF ... the minimum altitudes on that final approach would apply.

With respect to your other post regarding SLC, it appears that after taking a quick glance at the approach plate for RWY 17 into SLC, it appears that the minimum safe altitude within 25 NM in all directions (360 degrees) from Runway 17 is 13,000 feet. Of course there are specific altitudes listed on the approach charts that are lower than that 13,000 MSA, provided you are established on an identifiable instrument bearing – either from Ogden UT or somewhere on the final approach course. Essentially the same kinds of restrictions and limits are clearly printed on the chart for this airport as for Dillingham. Of course, SLC is at a much higher field elevation, but a similar set of instructions as those you criticized at Dillingham might say something like “…proceed direct to the Initial Approach Fix (IAF) to begin the approach, and maintain an altitude of 6,000 feet or above…” I wouldn’t think that the amount of traffic handled at SLC would ever allow such a set of circumstances, but, as in Dillingham, such an instruction would tell me to maintain whatever was the MSA for where I was located within 25 miles of the landing runway – that would be a minimum of 13,000 feet - until I was ON the final approach course and THEN, once getting to the FAF, I could descend to 6000 feet – which is the FAF crossing altitude – which happens to be a hundred feet lower than the instruction given to the Dillingham accident crew … which, you recall, was 2000 feet (or MSA) until reaching the FAF, where the crossing altitude for that fix is published as 1900 feet.
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