I have been looking through the FS2004 manual trying to work out what the backcourse button on the autopilot actually does?? I have found no reference to it...can anyone explain what a backcourse is and how the button works??
This should help, I got it off another website.......
Simple...it's an inexpensive way to get another instrument approach. With the exception of GPS and LORAN, all approaches require some sort of ground-based equipment in the vicinity of the airport. Someone makes a huge investment in equipment and real estate to provide an ILS approach to an airport--and the localizer signal radiates in TWO directions. The 'front course' provides directional guidance to the ILS runway, and the 'back course,' shoots out 180 degrees in the other direction. Since no additional equipment or real estate is needed to take advantage of the 'back course' signal, many airports have a 'back course approach' charted as a nonprecision approach to a runway that may otherwise not have an approach at all.
Could another approach be charted to the 'back course' runway using an NDB on the ILS compass locator, for instance? Sure--but since localizers, even on the back course, are much more precise than NDBs or even VORs, it's usually possible to get much lower instrument minimms on a 'back course' approach.
Short answer--the back course exists on any ILS, so if terrain and obstructions allow, why not chart a back course approach to the airport, almost for free?
There is a facet to back course approaches not mentioned in the other reply. Basically, a back course approach is a precision instrument landing approach to the opposite end of a runway with a ILS or ILS/DME approach. (i.e. Runway 27 has a published ILS approach. The back course is flown to runway 09).
Because you are flying in the opposite direction that the electronic course was designed for, the instrument needle is reversed on the back course. That means, when flying , you (or the autopilot) make course corrections TOWARD the needle on the front course and AWAY from the needle on the back course.
The reason the autopilot has a button for back course is that it needs to be able to fly in the correct direction when the course needle deviates and it can only do so if it "knows" which approach is being flown.
Oops! My previous reply should have read ...non-precison appraoch.