What does vnav do

Read More. Bridging the Gap: Airline Lessons. Bridging the Gap: Sterile Cockpit Procedures. Bridging the Gap: Stabilized Approaches. Cancel reply. Leave a Reply. Next Post Previous Post. Cart No products in the cart. Login Username or Email Lost Password? The software then loads all of the waypoints associated with that procedure from the database into the flight route.

It is not possible for you to enter or delete, separately or individually, waypoints associated with the approach procedure. Four waypoints in every approach procedure have special designations: 1 initial approach waypoint; 2 final approach waypoint; 3 missed approach waypoint; and 4 missed holding waypoint.

Most FMS require the pilot to choose whether to simply load, or load and activate, instrument approach procedures. When ATC tells you to expect a certain approach, select that approach from the menu and load it into the flight plan. Loading an approach adds its component waypoints to the end of the flight plan, but does not make them active. Once ATC clears you for the approach or, alternatively, begins providing radar vectors to intercept the final approach course , you must remember to activate the approach to receive course guidance and auto-sequencing.

In the case of a vectors-to-final approach, activating the vector-to-final causes the FMS to draw a course line along the final approach course. However, you must be prepared for two important changes during the approach.

The first important change occurs when the aircraft reaches a point within 30 NM of the destination airport. The second important change occurs 2 NM prior to reaching the final approach waypoint. As long as the annunciation for approach mode is displayed, you may continue the approach.

If, however, the computer fails to switch to approach mode, or the approach mode annunciation disappears, you must fly the published missed approach procedure. Keep in mind though, to fly them, you need a WAAS receiver.

A baro-aided GPS won't work. There's definitely an advantage to LPV. Unlike an ILS, which gets more and more sensitive and difficult to fly near and below DA, the scaling on an LPV approach transitions to a linear scaling as you approach the runway. It has a total course width of ' usually at the runway threshold. That ' of width at the threshold is the same as an ILS localizer at the threshold, but it doesn't get any tighter than that as you continue to touchdown.

LPV approaches get you low as well. But there is a downside. Since LPV approaches aren't considered precision approaches, you can't use precision alternate minimums for airports that only have LPV. There are a few more details as well, which you can find in AIM , paragraph D. Instead, they're just like an LNAV only approach, decreasing to 0. When that happens, you're stuck with the old-school LNAV only approach, complete with step-down altitudes.

But overall, having a glide path generated for you on a non-precision approach is a pretty nice thing to have. You have more choices than ever before on the type of vertically guided approach you fly, and that's true for almost all instrument airports in the US. Given the increased choices, you have better options to land the direction you want to at your destination. And even with the extra approach types you need to know, having more approaches to pick from makes flying safer and more convenient.

Become a better pilot.