RobertE Posted June 9, 2015 Report Share Posted June 9, 2015 My panel has a placard restricting using the autopilot on coupled Rnav approaches. It actually flies these approaches perfectly - much better than with the less certain ILS signal. Anyway, is this a general restriction on any autopilot designed before GPS came widely into use? And do most people observe the restriction? Quote Link to comment Share on other sites More sharing options...
carusoam Posted June 10, 2015 Report Share Posted June 10, 2015 The restriction is on coupled approaches... Are you using the coupled portion? If I remember correctly, the coupled approach can handle making the change automatically from a heading to a VOR or ILS. The AP can also hold altitude and follow down the ILS once intercepted... I have one of the early GPS boxes (KL90B) that is independent of the Nav/Com. One special switch handles all the wires that are the input for GPS or VOR/ILS... When the GPS is the source, a blue indicator light is on... Prior to that some GPSs were limited to their abilities for IFR use, especially for approaches. ILSs have no such restrictions that I am aware of. The sole purpose of an ILS is a precision approach. Some coupled approaches using an ILS may not be accomplished by some systems. Approaches from under the GS are one case, intercepting from above the G/S is a bigger technical challenge. Back to the coupled part of the restriction... I have a less capable AP (I think) KAP150. No restrictions of that sort. What Rnav device are you using? Is that what you were saying? Best regards, -a- Quote Link to comment Share on other sites More sharing options...
AndyFromCB Posted June 10, 2015 Report Share Posted June 10, 2015 Anthony, Do you have KAP or KFC? Does it have preselect? Quote Link to comment Share on other sites More sharing options...
carusoam Posted June 10, 2015 Report Share Posted June 10, 2015 KAP... It does a lot of things, but has no display beyond lighted buttons. Setting a climb or descent rate requires a button push for each 100fpm desired... Preselect doesn't sound familiar... There is 'in the now' settings, but no pre-anything memory. It is good at intercepting without needing standard 45° angles... GPSS or Aspen could really up the capabilities. The limits of my system are a small challenge when changing at waypoints or leveling off... The distracted nature of the pilot becomes readily obvious as he passes through an altitude or the next turn... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Bob - S50 Posted June 10, 2015 Report Share Posted June 10, 2015 We have a KFC 200 and we have no such placard. We do have one (but probably shouldn't) saying the KNS80 RNAV function is for VFR use only, even though the KNS80 meets the requirements for IFR use. Bob Quote Link to comment Share on other sites More sharing options...
mooniac15u Posted June 10, 2015 Report Share Posted June 10, 2015 Is the restriction related to a non-WAAS GPS source? Quote Link to comment Share on other sites More sharing options...
RobertE Posted June 12, 2015 Author Report Share Posted June 12, 2015 We have a KFC 200 and we have no such placard. We do have one (but probably shouldn't) saying the KNS80 RNAV function is for VFR use only, even though the KNS80 meets the requirements for IFR use. Bob Interesting. I too have a KFC 200. I don't know who or why that placard is there. I'll live with it ( but won't observe the restriction). Quote Link to comment Share on other sites More sharing options...
Cruiser Posted June 12, 2015 Report Share Posted June 12, 2015 It would be good to know why? Is the KFC200 original? Is there an additional manual added to the POH defining the AP function? You might find something there. Could it be a restriction on the RNAV source? What is it coupled to? Quote Link to comment Share on other sites More sharing options...
RobertE Posted June 12, 2015 Author Report Share Posted June 12, 2015 The KFC 200 is original (it came with my1981 J model). I have a manual for the A/P but I got it online. I can't recall if it addresses GPS approaches but I'm pretty sure a 1981 manual wouldn't? Did GPS exist back then for non-military purposes? I'm certain WAAS didn't. I've got a 430W so that's what it is coupled to but the placard was in the airplane before I had the 430W installed. It does sort of beg the question about what one does with a restriction that may have been relevant based on equipment that is no longer in the aircraft. Anyway, I was curious if others have this placard and it sounds as if the answer is no. Quote Link to comment Share on other sites More sharing options...
Cruiser Posted June 12, 2015 Report Share Posted June 12, 2015 Well if the placard was there before the GPS was installed the avionics shop should be able to answer your questions. If the AP is capable of coupled approaches then the installation should deal with that. It sounds like the placard was an oversight in not being removed. The following is from the Garmin 430W Flight Manual Supplemet that is included in you POH. Check it to see which is approved in your plane. "4.4 Coupling the Autopilot during approaches The Garmin 400W Series supports analog and digital (GPSS) control interfaces to an optionally installed autopilot. .............Autopilot coupling to GPS vertical guidance requires that the autopilot be engaged in an analog APR mode identical to an ILS. ................" following the above there are four options that are available for your installation, the avionics installer must mark one as approved for your use. Quote Link to comment Share on other sites More sharing options...
carusoam Posted June 13, 2015 Report Share Posted June 13, 2015 GPS time...I bought a hand held one around Y2K... Definitely not available in the 80s Rnav boxes originally combined two VOR inputs and created intersections that could be directly navigated to... From really old memories, -a- Quote Link to comment Share on other sites More sharing options...
Aerodon Posted June 13, 2015 Report Share Posted June 13, 2015 I flew a TR182 last week with a KFC200, and there is a placard saying 'no autopilot operation with flaps'. A little ridiculous for an autopilot capable of flying the GS. Aerodon Quote Link to comment Share on other sites More sharing options...
tmo Posted July 23, 2019 Report Share Posted July 23, 2019 Reviving this ole thread... Until the registration paperwork goes through I am stuck reading every piece of paper that came with the plane, and since the panel of a new-to-me M20K 231 is also tainted by said placard, I believe I traced it down to the KNS80 AFMS - on page 3, point 4 of section II - Limitations it says: A/P coupled R/N approaches are prohibited (placard installed just above artificial horizon). Limitation applies to KNS80 s/n 3865 and prior only. Coupled approaches are permissible with approved autopilot installations. Am I correct in understanding that a coupled R/Nav approach with the KFC200 driven by a GNS430W is not subject to this limitation? When I get rid of the KNS80 (flaky screen, 2nd DME freq digit dead) that placard can be removed as well, correct? Quote Link to comment Share on other sites More sharing options...
mooneyflyfast Posted July 24, 2019 Report Share Posted July 24, 2019 My 81 J with kfc200 has one of those labels. To me, it's talking about the old vor/dme based rnav approaches (the only kind they had when that sticker was affixed). I disregard it since I have a waas gps and fly lnav and vnav approaches. I have wondered why they call gps approaches "rnav". To me thats what my kns80 does--basically move a vor/dme station to a different location where you can navigate to or from it. Quote Link to comment Share on other sites More sharing options...
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