KRNM GPS9 Approach

Jaybird180

Jaybird180

Final Approach
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Jaybird180
Not studying approaches at this juncture per se, but in the video I was watching this approach was used as an example. The approach legs referenced altitudes as 3700 and 3200 from the IAF. The video mentioned the MSA (minimum safe altitude?) as 7700 (at the time - it's now 7800 on the chart).

Can someone explain what the MSA is for when the course fixes have you fly lower than that from IAF to FAF?

Also, what would cause MSA to change from 7700 (in 2003) to 7800 (present)?
 
MSA is the minimum altitude over a large area. If you happened to be offf airway and arriving at that airport you might use the MSA until you are established on a published portion of the approach. Likewise if you flew the approach, but botched the missed, you should be climbing to the MSA ASAP.

Basically, if you are tracking on the published approach segments use the published alts, if not use the MSA.

As for why it would change, probably a new obstruction since 2003.
 
Read the definition of Minimum Safe/Sector altitude in the Pilot/Controller Glossary. The MSA does not play any role in an instrument approach procedure...it is for emergency use only. However, to the best of my knowledge this is a US-only definition...some other countries figure the MSA into their approach procedures.

Bob Gardner
 
COFlyBoy said:
MSA is the minimum altitude over a large area. If you happened to be offf airway and arriving at that airport you might use the MSA until you are established on a published portion of the approach. Likewise if you flew the approach, but botched the missed, you should be climbing to the MSA ASAP.

Basically, if you are tracking on the published approach segments use the published alts, if not use the MSA.

As for why it would change, probably a new obstruction since 2003.
Click to expand...

I believe that you are to maintain the last assigned altitude until on a published segment...you don't get to choose your altitude unless you have been turned loose with a cruise clearance.

Bob Gardner
 
I would have just said because of all the brown stuff in the upper right corner. :)
 
bobmrg said:
I believe that you are to maintain the last assigned altitude until on a published segment...you don't get to choose your altitude unless you have been turned loose with a cruise clearance.

Bob Gardner
Click to expand...

The question came up on my checkride. The DPE wanted to know how I would determine what a safe off-route altitude would be (I guess for filing purposes). He was fishing for both the OROCA and the MSA from the approach plate.

I kind of ignored assigned altitudes since that doesn't help explain the difference.

MSA is really only helpful in an emergency. Somehow you have fallen off of the approach segments, you are not recieving vectors, and you don't want to bump into anything, climb to the MSA and sort your s**t out.
 
bobmrg said:
Read the definition of Minimum Safe/Sector altitude in the Pilot/Controller Glossary. The MSA does not play any role in an instrument approach procedure...it is for emergency use only. However, to the best of my knowledge this is a US-only definition...some other countries figure the MSA into their approach procedures.

Bob Gardner
Click to expand...
Good idea Bob. In fact in between posting the question and checking back, I looked it up in the IPH. Now if I'd done that beforehand my post count would be -2 :rofl:
 
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