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08-09-2019, 05:05 AM

#34

Gundriver64

Gets Weekends Off

Joined APC: Jul 2017

Posts: 249

Quote:

Originally Posted by P180 Jockey

According to Flight Safety, it does for a VOR or GPS approach. You can check with them. I just did.

I submit the exact same sequence might be used; only difference is the MDA/DA will be at the published Circle to Land altitude, which is designed to allow for maneuver to the Landing Runway. VNAV will get you there; Dive and Drive requires you to assure you'll arrive in time to Drive.

My only point here is that a consistent sequence, across approach types, seems to me to be a desirable thing. Whether it's an ILS or a GPS you are required to reconfigure at DA/MDA. If you don't on an ILS, you're going to auger in; if you don't on a GPS or VOR, you're going to stall...and auger in.

So, knowing that you MUST take action at (or approaching MDA), why not fly the (more stabilized) VNAV toward the MDA, initiating the GA decision when applicable? Just like an ILS. Same procedures. Same sequence.

I realize we're talking King Air's here and I'm interloping with discussion of the P180. But I can tell you, the P180 does NOT provide very much forward visibility in the "Drive" portion of a Dive and Drive approach. Here's a great article on why that type of sequence is no longer in favor: From Non-Precision to Precision-Like Approaches

I don't find it curious that Beech might have a different manual of arms on this issue than does Piaggio. Perhaps the P180 is not as well suited to a Dive and Drive approach configuration. Perhaps it simply demonstrates that the experts differ in opinion also. That would mean nobody is wrong. ;-)

Then there is the question is MDA MINIMUM descent altitude or is that just an advisory thing only? Would you stake a type ride on selecting APPR to the MDA?

The airports that I frequent for evals/training all have at least one RNAV (GPS) approaches. I can fly most of these approaches blindfolded. I experiment with the LNAV MDA, LP minima. Pretty much 100% of the time I can acquire the runway environment sooner and be in a better position to land using NAV and VS (1000 fpm max) versus NAV/VNAV. I prefer that my new guys I teach/evaluate use the full automation (VNAV). Guys, that I give PIC rides to will have at least one approach limited to VS. I really throw them for a loop when I dim the FMS brightness full down and tell them to execute me an ILS raw data ;-)

Last edited by Gundriver64; 08-09-2019 at 05:30 AM.

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