Hey guys I understand what lnav and vnav do but I wanted some clarification on the real world use of these systems. For example Say your flying a simple Rnav departure out of an airport. What would be the first autopilot system used according to real ng SOP's. What AP cmds need to be used at certain times. Something like that. I know a simple understanding of this kind of system but I would like to fly this plane like they do in real life. I am aware that most of airline flying is on lnav and vnav. However I want to know when is it an acceptable time to turn on and off certain functions and cmds. I would like to know the real world standard autopilot functions from leaving the runway to touching down somewhere else. If anyone could help clarify at all that would be great. I feel that some people probably have this same question and just haven't thought about it to much or something along those lines. I'm not asking for a huge in depth step by step tutorial (it would be nice though) I simply want to see the corresponding procedures involved with autopilot in chronological order.

This thread might offer some insight: http://forum.avsim.net/topic/338546-so-how-many-looked-into-this/The discussion in the thread focuses mostly on 10.7, but with the current 10.8A, VNAV and LNAV can both be armed on the ground, with LNAV going active at 50 feet, and VNAV coming on at 400. Both modes could then remain on as long as the crew desired.

Hi,

However I want to know when is it an acceptable time to turn on and off certain functions and cmds.

You're the Commander - you decide!In real-world airline ops, SOP (Standard Operating Procedures) are what generally dictate what is used when (e.g. many airlines mandate use of the flight director AT ALL TIMES). In that case you would use the flight director all the time unless it failed or you had good reason not to use it (e.g. failure of another system or unreliable indications). Whilst similar SOPs may exist for things like LNAV and VNAV, it is ultimately the decision of the crew on the day regarding what is used, when.Don't forget to hand-fly your aircraft occasionally. When the SHTF, the middle of the emergency is NOT the time to start learning how the aircraft handles at high cruise altitudes.Best regards,Robin.

You should perhaps check out this book:http://www.amazon.com/Flying-Boeing-700-Flight-Simulators/dp/0936283106/ref=sr_1_1?ie=UTF8&s=books&qid=1309973446&sr=8-1Al

One case where the pilot flying decides where A/P is used or not, or working with the A/P via MCP control not using VNAV is arrival or departure in turbulent weather or heavy gusting winds. These conditions could take aircraft performance modifications which would fall out of the A/P range to correct and follow rapid changes and pilot mediation would be advisable.