Proline 21 can be programmed with altitudes at waypoints; in the descent it’s easy, it’s how it flies STARS, but you need to manage the power in the types I fly. It’s very easy to end up in overspeed mode. It doesn’t initiate a climb, as autopilot initiated climbs without autothrottles would be dangerous, but the levels programmed automatically feed through to the altitude preselect so it levels off as appropriate, say in a SID.
I apologise for my Naivety – i’m a VFR only guy, but just like fancy tech :)
That’s really interesting info – I totally assumed that having different waypoints & levels and therefore vertical navigation in the cruise was something that all these units would have had – fascinating to hear they do not.
However if the Avidyne and Gx000 can do some element of it, hopefully Dynon will follow along with the same concepts – seems a logical technical improvement. Obviously throttle setting would need adjusting unless you’re happy with speed altering accordingly during climb/descent.
Total spend on my avionics is 29,000GBP. This includes 3x 10" touch screens, 2x COM, 1×XPDR, PMA450 Audio, TM250 traffic, analogue backups, Autopilot Panel & Servos with auto-trim and VP-X power control. That’s a lot of bang for the buck, and i’m just trying to figure out what i can do without spending a sizable % of that again on a garmin.
I think the main issue, Carl, is that you don’t have auto throttle (only the top end business jets and airliners have that), so while a programmed descent is obviously OK, a climb could be programmed which is impossible due to the climb performance.
That is one of the things you will discover you need to watch when using any autopilot. It’s easy to set up say +500fpm which your plane will do, but only up to some altitude. As you climb, the speed will reduce (to maintain the +500fpm) and eventually it will stall. For example my TB20 would stall at about FL120 (depending on some other factors). This is a non-event if you are awake and watching it but it does catch a lot of people out.
I am not familiar with your actual equipment. Maybe you can post the exact units so others can advise? If I was doing this job I would be most concerned about the inter-operability of the various boxes. There is a lot of stuff in avionics which doesn’t work together properly – even if you were 100% certified. A lot of people have bolted in Box X and Box Y and then found the two won’t talk to each other. Obviously they end up with a “British builder fait accompli” situation i.e. they are hardly going to rip it all out because it is only 75% right. So make sure everything works, get that confirmation from a single seller (you will have zero practical comeback if X says their gear works with somebody else’s Y but this turns out to be false) and get it in writing. I have abandoned various upgrade projects because such and such could not be confirmed, and usually discovered that my instict was right and it would not have actually worked.
A Cirrus with Perspective Avionics can of course fly a 3D profile and automatically and hands off fly an RNAV approach including the altitude changes before the FAF.
And so can many other planes with modern avionics and A/Ps
A Cirrus with Perspective Avionics can of course fly a 3D profile and automatically and hands off fly an RNAV approach including the altitude changes before the FAF.
And so can many other planes with modern avionics and A/Ps
So, you can program multiple enroute waypoints, different altitudes for each, and it will automatically climb and descend, no manual intervention at any stage?
What engine have you got? Sounds like one of these – I wonder how the paperwork was done… it must have been a DER job at least.
If it can do that, I will start a new thread on this later so we don’t mess up Carl’s one.
You don’t need autothrottle to fly such a 3D profile. You set it to whatever you feel like, and will go a bit faster downhill. And down you also don’t need to adjust the mixer, unless the alt change is large and you get a rough engine.
I am not sure about enroute, AeroPlus and Jason will know that, but it will fly the approach profile with all the descents from the IAF down.
(No i don’t have that F-1 engine, that’s only used for the first stage of the Saturn V)
Indeed. With the Garmin Perspective you can fly vertical profiles all the way down automatically. You still have to control the power and mixture.
However, in most cases ATC will give you intermediate descend instructions that do not match the VNAV profile, so it is rare that you get to fly it fully and automatically, but it is there.
