The video guy covers the calculations and draws a diagram, I just can't bring myself to watch it again. I don't recall what he specifically says about following the correct v-path as depicted on the jepp chart, but he does say if you follow the g1000 depicted path it will fly you into the stack.
EDIT: So, I watched the diagram part again and he does say if you fly the (unpublished / G1000) path of 3.59 from the JAMID to RW20 you might actually hit the stack. He mentions 3.75 is not applicable due to the VASI being decommissioned years ago. However, does a published VDA really need working VASI to be valid? The VDA merely references the runway touchdown point, does it not?
The FAA's Chart User's Guide for the Profile View information reads:
"A VDA and TCH may be published on non-precision approaches....The VDA is strictly advisory and provides a means to establish a stabilized descent to the MDA. The presence of a VDA does not guarantee obstacle protection in the visual segment. If there are obstacles in the visual segment that could cause an aircraft to destabilize the approach between MDA and touchdown, the profile will not show a VDA and will instead show a note that states “Visual Segment-Obstacles”.
That last obstacle note is not on either the Jepp or FAA chart, maybe because if the 3.75 published is flown, it would not cause an aircraft to destabilize?
As someone else mentioned, this is only an LNAV approach, so it is either dive and drive or correctly apply the VDA if flying a constant descent. This VDA is published from the step down fix. The AC 120-108 the video guy quotes reads:
"However, in some cases, the VDA is calculated from the stepdown fix altitude to the TCH. In this situation, the VDA is published on the IAP following the associated stepdown fix (see Appendix 1, Figure 5, Instrument Approach Procedures with Controlling Stepdown Fix). In most cases, the descent angle between the FAF altitude and the stepdown fix altitude is slightly shallower than the published VDA for the segment between the stepdown fix and the runway. Operators should determine how they would like their pilots to fly the approach."
So, other than the FAA not noting the start of the VDA as clearly as the Jepp chart does and both still reference a VGSI which is not functional, is there really anything "illegal" about this approach? Maybe the video guy should be more wound up about a) why Garmin allows this new vertical path to change as it does and not calculate based on the JAMID stepdown fix or b) why the airplane was flying the Garmin derived 3.59 degree path to the runway, if in fact that is what the pilot was actually doing.