Sim Challenge: Trusting the Wrong Glidepath
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A simulator is the perfect place to practice judgment, timing, and managing workload when the pressure is on. Our Sim Challenges make it easy to get a good workout—at home—using Microsoft Flight Simulator or X-Plane. Along the way, you’ll answer thought-provoking questions and learn from an expert’s real-world insights.
In this month’s challenge, you’ll discover the difference between approved vertical guidance and advisory vertical guidance—and what can happen if you follow advisory vertical guidance below MDA.
Take the challenge!
Lee Smith is an ATP-rated pilot, flight instructor, and software engineer in Maryland who enjoys bridging the gap between flight operations and technology. With a background in corporate aviation and over a decade of experience supporting flight procedure design and analysis, he brings both cockpit experience and engineering insights to complex IFR topics. Lee's work has appeared in IFR Magazine, IFR Refresher, Aviation Safety, and AOPA. He also writes The Logical Skies available at LogicalSkies.Substack.com exploring why the aviation system works the way it does.
Latest posts by Lee Smith (see all)
- What Lies Beneath the MDA - June 25, 2026
- Sim Challenge: Trusting the Wrong Glidepath - June 23, 2026
- Sim Challenge: The Lowdown (IFR) - February 3, 2026
Great scenario once again. This may save someone’s life. Good explanation of the difference between LPV and +V vertical guidance.
I am surprised that the lawyers for the companies that put out +V guidance do not remove the +V guidance at the airports where terrain puts the aircraft at risk if the glideslope is flown beyond MDA. Leaving it in is asking for someone to eventually make the mistake. The autopilot will happily follow the glideslope into the ground. That’s bad policy. Better to just have the approach in the database as LNAV without +V. It’s true the pilot could just select a VS mode on their autopilot and follow it down below the MDA in that case, but at least they won’t have a GS needle showing them they are on glideslope when they crash!
Keep the Sim Challenges coming please. I fly all of them on my ELITE simulator. It models the 430W/530W perfectly and I have a hardware interface. GTNs are available as an option, but I don’t have one in my Bonanza, so no reason to pay for the option.
I’ll also add that Garmin Pilot Smartcharts for N23 and N27 show the terrain on the bottom section of the approach plate, making it more obvious the glidepath is not clear on the +V or the 3 degree glideslope.
I noticed that for N27 the Garmin Smartchart shows the protected area for the circling approach, nice feature.
For N27, I used a split screen showing SynVis and the SmartChart. One really nice feature of the SynVis page in this case besides seeing the terrain when IMC, is also that the terrain turned yellow for the area for which I was < 500 above. Pretty neat in real time to see this in action.