jwk34953

Al, Thank you for considering this, it would be nice to have the most realistic simulation possible, but most of us have to put food on the table too. I'll look forward to hearing more later when you can work it into your schedule, in the meantime I'll continue to fly- and enjoy- your C172SP Wide Panel ! Regards, jk

Hi Alan, I contacted AOPA today and spoke to a representative in the Pilot Information dept. He suggested I call the owner of the avionics shop that has worked on a number of the aircraft owned and rebuilt for AOPA. The gentleman I was referred to was very familiar with the KAP-140... the kind of guy who when you ask him what time it is, he not only tells you the time, but also what the origin of timekeeping is and how the watch works in detail. Here is what he told me... There is no 'on-off' switch for the KAP-140. The power comes directly from the power bus breaker, either from a separate panel-mounted switch or through the avionics master switch. Cycling the AP switch does not initiate the power on self test, that only occurs when the power is first applied to the KAP-140 by the auxiliary panel-mounted switch or the avionics master switch, depending on how it was wired when installed. Cycling the AP switch suspends the autopilot function by disconnecting the logic from the servos that that control various aspects of the aircraft control by the autopilot - in other words, the internal logic always remains powered on monitoring the system for faults, and there is no further power on self test until the power is disconnected and then restored. So, effectively it does the same thing as the Off/On/Auto Flight Director switch on the C172SP aircraft provided with X-Plane does when it is switched between 'On' and 'Auto'. Is there someone at X-Plane I should pass this info on to?

Thanks for the reply Alan, I've got that same manual- I may well be completely wrong about this, but on page 8 it refers to the 'power on test' being performed upon 'power application', and further it refers to it as a 'preflight test sequence'. On page 9 it refers to the 'AP' switch as the 'autopilot engage/disengage button'. This is what leads me to believe that it may be 'always on', and that the 'AP' switch is not meant to power on the KAP-140, just to engage/disengage. I'll try to find someone at the AOPA (aircraft owners and pilots association) here in the US to see if I can get a definitive answer and get back to you. I've never flown with this autopilot, in fact I've only flown one other plane with an autopilot as copilot, and it did not work this way- it had separate 'power' and 'activate' switches and that seems to make a lot of sense to me- for instance if you were in the process of entering an approach and had some setting wrong and the aircraft started doing something you didn't want, you could disengage the AP and correct your settings, then re-engage it without having to wait the 28.8 seconds it takes for the POST to complete before you could use it again- but that's just an opinion, it doesn't mean it's the way the KAP-140 should work. I'm not trying to redesign it, I just want to know if that's the way it's supposed to work so it operates like the real thing. One thing that the manual mentions repeatedly may shed some light on the Auto Pilot assisted approach I that went really wrong that I spoke about above, "Intercept angles greater than 45 degrees can result in course overshoot when close to the station. Therefore, intercept angles greater than 45 degrees are not recommended". While I didn't enter the localizer at 90 degrees, I may well have been somewhat beyond 45 degrees when intercepting the localizer, and to compound this I'm pretty certain I was inside the FAF which probably qualifies for 'close to the station' - 2 strikes (baseball reference, if you didn't know) against me. In case you haven't seen this one, here's another document that's more procedural oriented on how to fly various approaches with the KAP-140: http://www.gaviators.com/charter/autopilot-KAP-140 Thanks Mario, yes I did press the APR button, I was flying at close to the correct glideslope altitude when I passed through the localizer and throughout the zig-zag course it was flew the KAP-140 started the aircraft down the what approximated the the correct descent rate of the glideslope, almost to the ground, at which point I interceded as I have a strong dislike for crashing, even in a simulator. On a positive note, I'm making some headway on GPS approaches. I ran across something in the GNS 430W manual about vectored approaches that I hadn't considered... that is that the 45 degree intercept point had to occur prior to the FAF- with the accuracy of GPS I never considered that would be necessary. The next vectored LNAV+V approached I made went perfectly, down the center of the runway and right down the glideslope. It was a thing of beauty. I was so happy, I flew a second time. This time when I came out of the clouds I was offset from the runway to the right by quite a distance, but the heading was perfect and so was the glideslope- just outside the airport. Then I flew a 3rd approach and the same thing happened except it was offset to the left. This time when I passed the inner marker I manually held altitude to keep from crashing while the GPS/autopilot continued to fly on the correct heading parallel to the runway. The GNS-430 reported I was 0.5 miles from the runway as I passed the runway threshold. Based on my less than scientific visual observation on the second approach I'd say that my offset to the right was exactly the same- 0.5 miles from the expected runway and it too flew a parallel course with positive control of heading and vertical descent rate until I took over manually. I'll go bang my head against it later and see what happens, but at least I know vertical and horizontal axis control is possible, so once I'm certain I've got my sequencing of the GPS & autopilot settings & controls down, everything should work perfectly, right? I hope we see more of the GNS 430W options incorporated into the SIM model. Some of the features like airport frequencies lists and other things that take some workload off the pilot would be great to have implemented. This new implementation is great, I'm hoping to see it continue to grow. The C177SP Wide Panel has become the only aircraft I fly now- THANKS ALAN!!! ... it feels very close to the C177 I used to own, the main differences being that it had no wing struts, had a variable pitch prop and had a stabilator instead of an elevator. Time to go work on sorting out my approaches...

Thanks Mario, I really appreciate your reply. The version number I stated was my best recollection, it was the last non-beta update downloaded after I installed v10 from DVDs until I got the message recently on startup that a non-beta version of 10.30 (build 103010) was available, which I updated to. Not having any way to go back and check the version, I was depending on what I could recollect, having seen the version number once last April or May, Yes, the circuit breaker has been in, the GPS has been on, but I didn't know about the NAV/GPS switch to the left of the COM panel- it's small and I overlooked it until I read your post and looked more closely- thanks, good to know. I used your directions exactly as written, and while I could hear the switch sound when clicking on it, there was no indication of it actually doing anything, and it remained unlit. Then I found that it becomes active (lit) only after you turn on the autopilot and then select the NAV button- only then it lights up and works. After doing some tests, it appears that the switch defaults to the 'COM' position when X-Plane starts up, so it was in the wrong position for all of my previous attempts to fly GPS approaches. This autopilot seemed odd to me because there didn't seem to be any way to disengage it except to turn it off, which is unlike other autopilots I've seen that can be switched into a standby mode. I found an operation manual for the two-axis King Bendix KAP-140 autopilot this appears to be modeled after and found that the AP button is supposed to be for engaging and dis-engaging the auto pilot- they make no mention of a separate way of powering it on, so maybe it's supposed to always be on when the avionics master switch is on and the breaker is in- I don't know, I've never seen a real one, but it's a real disadvantage not being able to disengage it without power-cycling it which is always followed by a lengthy POST before it becomes available- anyone who's used the real thing please let me know how this really works. During normal operations and under certain conditions the autopilot does disengage itself as it is supposed to so if the AP switch is really meant to only engage/disengage the autopilot it seems like it might be possible to change the model accordingly. After having read the KAP-140 manual and becoming more familiar with it's modes, I made a direct-to GPS flight from KSEA to KBFI, which was successful, flying me over the the middle of the airport. After that I tried making a GPS approach to KBFI and that was a failure. The proper entries were made into the GNS-430, but I was unable to make an autonomous 45 degree entry on the localizer... I flew right up to the localizer and the autopilot turned me on an outbound course away from KBFI, flew me out a distance, made an approximately 45 degree right, flew me out a ways then made a series of what appeared to be in random directions until I disengaged the ap and flew it back manually. I'm still studying the GNS-430 manual to see what I might have done wrong. One thing that needs clarification is GPS vertical guidance. In the developer.x-plane blog thread ( http://developer.x-plane.com/2014/03/new-approach-capable-gps-navigator-in-x-plane-10-30/ ) Philipp Munzel replied that "No vertical guidance yet, as the navdata is currently lacking one field that is necessary to get the final descend to the MDA right. Apart from that, the logic for LPV is already in, including the angular-type CDI sensitivity when switching from TERM to LPV." This was dated April 1, 2014... nothing since then about it that I could find, so I wonder if this is working yet. To try to isolate whether whether my above GPS approach was an autopilot or GPS problem by making an autopilot assisted ILS approach, I switched the autopilot navigation source to Nav radio 1 and tried to shoot the ILS to KBFI rwy 31L approaching from south of KSEA and making a 45 degree entry onto the localizer. That's when things really got strange. As I approached the localizer the autopilot started making series of turns to the left and right of my entry course (toward and away from the airport) while descending, right through the localizer and out the other side, eventually making a left turn back towards the localizer. While flying back towards the airfield the autopilot narrowly missed striking the roofs of several homes on a hill to the east of the runway (I may have given it a little help missing them). I let the autopilot keep flying the aircraft to see what would happen. It flew through the localizer about a half mile off the south end of the runway, made a low right turn back towards the runway narrowly missing the roofs of buildings on the airport and crossed the runway narrowly missing buildings on the other side (I intervened somewhat here by pulling back on the yoke) then turned again back towards the runway. I this point I switched off the auto pilot and saved my life, flew back to KSEA and gave it a rest. The CDI localizer and glideslope were accurately portraying the glideslope throughout this approach, but the autopilot was unable to fly the approach. At this point I'm not sure what to think. The autopilot clearly is aware of where the localizer and glideslope are, but don't seem to be able to follow the CDI... are my expectations too high to think the autopilot should be able to fly the aircraft down the glideslope to the middle marker? Is there something I missed or forgot? I don't know. I spent 4 hours after I wrote the above attempting to fly a variety of GPS & ILS autopilot augmented approaches at a variety of airports and every one failed to sequence the autopilot through heading to nav to localizer and glideslope tracking. I appreciate any thoughts or ideas anyone has in resolving this. In the meantime, I continue to RTFM's and try to figure out if there's something I'm doing wrong.

Hi Al, thanks for the Wide Panel Project, I've been using for a month or so to refresh my instrument skills. I've never flown any GPS approaches before and after 3 days of reading the the 430w manual, searching online, and doing some Garmin tutorials without having completed any GPS approaches with the aid of autopilot, the one thing I'm certain of is that I don't understand the interaction of the autopilot and the GPS. Also, since updating from X-Plane 10.26 to 10.30, I'm not sure that the new 430W in X-Plane is compatible with C172SP Wide Panel any more after reading other people having had to make changes to their non- X-Plane native aircraft in Planemaker to get the new 430W to work with their add-on aircraft. If you could let me know about the compatibility issue and also tell me what the model of the autopilot is modeled after (it looks like a King, but the resolution is not high enough to pick up the manufacturer or model on it) I might be able to find a manual or some instructions for it that would help me figure it out- it would be nice to know the models for all the avionics, the only ones I've been able to figure out for sure are the 430W and the KX-165A. Many thanks, jwk Of course... right after I posted this I finally found that this is a Bendix King KAP 140 autopilot... I didn't recognize it because I didn't know it came in 3 variants with different features, all of which share the same name. Here are some links to manuals and instructions should anyone else be interested: https://dealer.bendixking.com/servlet/com.honeywell.aes.utility.PDFDownLoadServlet?FileName=/TechPubs/repository/006-18034-0000_3.pdf http://wiki.flightgear.org/Bendix/King_KAP140_Autopilot http://www.gaviators.com/charter/autopilot-KAP-140 ...hope you can still let me know about compatibility of new GNS 430W with the C172SP Wide Panel Project, and models of other avionics in it... Thanks!