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#71 LNAV - Autopilot wobbles when passing over a VOR station
Originally created by: pedromor...@gmail.com
Originally owned by: pedromor...@gmail.com
What steps will reproduce the problem?
1. set aircraft on NAV radial to a VOR station, and give it ample time to
be "on course"
2. as aircraft passes over VOR station, it will "wobble" left right for a
few moments.
3. This is across a few (assumed all) aircraft that can maintain NAV hold
What is the expected output? What do you see instead?
* The aircraft passes over a VOR station and does not "wobble" as it passes
over.
* The same scenario applies with a missed approach, maintaining a localiser
heading. When it reached the end of the runway then it wobbles also and
goes everywhere (maybe another issue)
I'm not sure what this bug is, as a few aircraft with AP enabled (Bravo,
787, 777, beachcraft) etc perform the same way.
The expected is that the aircraft would
1) reach the vor on autopilot lnav and simply pass over as intrunemtation
changes wildly
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Originally posted by: pedromor...@gmail.com
Similar happens with a localizer.
1) set aircraft to follow localiser for landing, but not "landing"..
2) aircraft will follow the runway centre line..
3) when it passes over the localiser at the end of the runway.. it "wobbles"
4) then after a few it goes off in all sorts of directions.. instead of "straight on"
Summary: LNAV - Autopilot wobbles when passing over a VOR station
Status: Accepted
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Originally posted by: zakalawe@mac.com
Depending on the cockpit instrument, some wobble is expected passing over a VOR station (or localizer
transmitter) - search for 'zone of confusion' to find many pages discussing this behaviour. The real issue is that
some autopilots and cockpit displays use numerical filtering to mask the effect from the pilot, but this is
generally not modelled in FlightGear.
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Originally posted by: cumuluni...@gmail.com
This is common behaviour of some real life autopilots and even mentioned in the respective operating manuals. It is explicitely mentioned in the CENTURYIII A/P manual and I can confirm that real life behaviour is close to the that seen in FlightGear.
When it comes to localizers, their signals are usually not valid any more when flying past the station (some _might_ have a published backcourse).
There is no global action necessary for this issue, probably individual aircraft's autopilots need some tuning, but that has to be checked in detail for every aircraft/autopilot combination.
Status: WontFix
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Originally posted by: bre...@gmail.com
(No comment was entered for this change.)
Status: Temp
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Originally posted by: bre...@gmail.com
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Status: WontFix