Originally Posted by
JohnBurke
Certain simulators do exhibit that problem; the student may never climb above 5,000 during the entire exercise, with multiple approaches, but the FMC needs to be re-cruised in order to generate a top of descent for the subsequent approach. It sounds like the case with this simulator, something not found in the airplane, but which is occurring in the sim, with little explanation as to why it's being one. Accordingly, one could search the procedure in the FCOM or FCTM, and not find a reasonable explnation. Having to re-cruise the FMC lends to confusion in that case, especially if it's simply explained away as a "simism." The original poster described the sim instructors leaning over his shoulder and setting it in the box, perhaps to facilitate the procedure so the student won't get in the habit of learning a behavior that is only required in that simulator.
Regardless, if protecting the FAF, that's something that's done on the MCP. Other than a sim-only process of re-cruising the box to establish a TOD, then the only altitude inputs to the box might be making an altitude a hard altitude, as opposed to an above or below altitude. The instructor should explain, if there's confusion, and that's best handled both by doing classroom work, and perhaps stopping the sim to clarify, before continuing on a procedure. That shouldn't be coming up at a checkride, though; any confusion on the procedure should have surfaced and been handled well before arriving at a checkride. Definitely before the re-test. As noted before, however, despite any desire to "overachieve," don't add to the procedure or improvise. In the sim, it might result in a busted checkride. In the field, it might result in a busted airplane.
Fair enough, JB. I can understand the "sim-ism" of having to re-cruise the box in certain circumstances. However, it's also a potential real-world task in the event of a MAP and re-attempt at another approach requiring VNAV. So, a clear understanding of the, why, when and how is required, regardless of the more common times it might be required in a training sim.
I've flown a lot of non-precision approaches using VNAV and not once have I "protected" the FAF using the MCP in the last 15 years, at least. That was back in dive and drive days. Now FAF is protected by a large font altitude restriction in the FMS. In the "old days" we set mins in the MCP. Now, once cleared, established on the approach and protected by such large font FMS entries, the MCP is rolled down to TDZE rounded up. That allows a VNAV descent to mins that are treated like a DA, not an MDA. I can't imagine a modern 121 airline is currently teaching to protect the FAF using the MCP. But, maybe I'm wrong.