Absolutely, the autopilot which is following the flight director, which is following the CDI will simply respond to any course deviation whether it is actually real or just a signal anomaly.
Wow! Amazing!
Where I come from, this would be classified as completely unacceptable design theory/strategy. To systematically link [AP to FD to CDI] and thereby exceedingly increase the probability of negative anomalistic input leading to an undesired result/outcome - by design - is bizarre. I mean, if we know the CDI is pegged to the ground based ILS and we also know that the approach to landing is the most critical phase of flight [placing in to a high mission critical index] then how did anyone make the decision to proceed with such a auto-pilot driven design strategy?
I'm shaking in my boots. Why? Because this is not the first time I've heard of this happening. This happened sometime in late 2008, and for the exact same reason. Some problem with the ILS system causing external input into the aircraft which effectively took the aircraft out of the pilots control, at least temporarily. And, I read about it happening again, in early 2008 and I think again sometime in late 2007. These are just the times that I am aware of - I'm sure I don't know about all of them. Wow!
It doesn't know what's real and what's not, that's why the PF has to continually monitor the approach when coupled to an autopilot.
How about just dump ALL AP approaches? Just don't approve them. At least until the design flaws can be logically worked out of the system.
Thus the push for WAAS and LAAS (GPS) approaches that provide CAT I like minimums. At the moment, that's an LPV,...
And, ironically, this was being worked on back in 2008 by IS&S for the PC-12. Was is not a PC-12 that recently went down in Montana? I'm not suggesting that it went down for the auto-pilot/LPV reason, but I just find the timing a bit ironic - that's all.
http://www.aviationtoday.com/categories/bga/26721.html...but in the future LAAS will allow CAT I or lower mins published as GLS PA.
So, you are talking 200 ft minimums before the DA or the MAP? I get confused - I'm so green, still. I know I'm pushing things, but I want to take every opportunity to learn something I did not know before. The DA and the MAP have always caused me some slight confusion.
I guess with the GLS [GNSS/GPS technology based] you get the vertical guidance and that would be a huge support tool for PA's, yes/no?
If you've flown a WAAS approach, you can see how much smoother and precise the needles are. No wiggly CDI and GS needles like on many ILS approaches.
I've yet to begin my dual. That's why reading about this again is freaking me out. There is a ton of high-performance twin jet instrument flying [especially coming home at night] in my near future and learning that I could be an ILS guinea pig because of some anomaly that should have never been allowed to persist into the system, is rather an uncomfortable thought to take into my initial training with me, to say the least.
On the CJ3, we'll often load the ILS frequency on both NAV 1 and NAV 2, but will display FMS on the PNF's PFD so we can cross reference the lateral course indications between the ILS and FMS.
But, that does not yield any vertical references does it? The particular aircraft being discussed here was the victim of a vertical reference anomaly - is that correct? So, how does [correct when I am wrong please] having two lateral references on two different screens, help with the vertical reference problem that ultimately causes the auto-pilot to increase pitch attitude too much?
Do I understand the problem correctly? Again, I know that I'm still a babe in the woods here on this stuff.