Is there anything significantly different (e.g. structurally) in the G1000 Jetprops?
I know there were several structural mods done to the older PA46 airframes, but those were way before the G1000 PA46 arrived.
The point is that the G1000 is barely relevant when for a relatively irrelevant (on the overall scale) cost you can install e.g. a G500. Except you can’t have the GFC700 autopilot without a G1000…
The late non-G1000 Jetprops had the KFC225 which has a ~ 100% failure rate on many airframes but the PA46 seems to not suffer from it much, or at all in some cases. I think I know why this is, but it’s complicated and to do with the installation and other avionics. And the KFC225 works great, is very accurate in turbulence, and accepts direct ARINC429 roll steering.
Peter wrote:
Is there anything significantly different (e.g. structurally) in the G1000 Jetprops?I know there were several structural mods done to the older PA46 airframes, but those were way before the G1000 PA46 arrived.
The point is that the G1000 is barely relevant when for a relatively irrelevant (on the overall scale) cost you can install e.g. a G500. Except you can’t have the GFC700 autopilot without a G1000…
The late non-G1000 Jetprops had the KFC225 which has a ~ 100% failure rate on many airframes but the PA46 seems to not suffer from it much, or at all in some cases. I think I know why this is, but it’s complicated and to do with the installation and other avionics. And the KFC225 works great, is very accurate in turbulence, and accepts direct ARINC429 roll steering.
You mean with the Meridian? Yes, the tail is different as are numerous systems. It is quite a different aircraft as it is not
The GFC700 is arguably the part of the G1000 you want.
The 225 autopilot is OK but it isn’t a modern digital autopilot like the 700 or DFC 90/100.
The 225 autopilot is OK but it isn’t a modern digital autopilot like the 700 or DFC 90/100.
The KFC225 is 100% digital. All the control loops are in software.
The previous KFC units are decades older, despite having the same prefix, and they are analog.
Peter wrote:
The KFC225 is 100% digital. All the control loops are in software.The previous KFC units are decades older, despite having the same prefix, and they are analog.
Ok, my mistake. Certainly those I know who had them are much happier when replaced with the DFC90.
Certainly those I know who had them are much happier when replaced with the DFC90.
Did they tell you why exactly?
I am not surprised if they had the KFC225 servo failures. But as I said those seem to be very rare on the PA46 airframe.
Otherwise, I doubt anybody would tell the difference between a KFC225 with roll steering and any other autopilot with the same function set. Obviously if you want e.g. IAS hold that’s different.
The DFC90 is not without issues in retrofits, but I can’t relate the (utterly comical) stories I have heard because they would identify the owners – because there are so few of them on those aircraft types, in Europe. Actually I vaguely recall some accounts were posted here years ago, but that was an SR22.
The GFC700 is probably good but then Garmin control the whole package.
Peter wrote:
Did they tell you why exactly?
Look at the feature list of the DFC90. It is hands down the best AP available now and it does feature IAS pitch mode, which is one of the things that only the DCF and the G700 do feature. Alone that would warrant a very close look at it.
Sure, but an autopilot …. flies the plane. It doesn’t need to make the tea as well.
I agree a IAS hold mode is nice but a PIT mode does a similar thing in terms of avoiding a stall, and this issue is less critical with a turboprop anyway which has so mch more spare power. IAS mode still runs out of power, long before you reach the operating ceiling, as the IAS falls back to Vs plus not much, and the plan is to level off before that.
Peter wrote:
I agree a IAS hold mode is nice but a PIT mode does a similar thing in terms of avoiding a stall, and this issue is less critical with a turboprop anyway which has so mch more spare power. IAS mode still runs out of power, long before you reach the operating ceiling, as the IAS falls back to Vs plus not much, and the plan is to level off before that.
IAS/FLC mode is incredibly useful both for avoiding a stall and for aircraft that fly near Vmo or Mmo. I use it mostly in the climb but also in descent.
As to what is wrong with the KFC, It was mostly functionality and integration with modern GPS navigators. Can’t be the servos as these are kept with the DFC-90.
Peter wrote:
I agree a IAS hold mode is nice but a PIT mode does a similar thing in terms of avoiding a stall, and this issue is less critical with a turboprop anyway which has so mch more spare power. IAS mode still runs out of power, long before you reach the operating ceiling, as the IAS falls back to Vs plus not much, and the plan is to level off before that.
Beg yer pardon, but have you ever actually used an AP which has this feature vs the usual GA autopilots?
IAS/FLC mode is a different world from what we know in the King/STEC world. It is quite safe in comparison to VS, it allows you to fly a proper speed profile whereas all vertical modes are prone to possible stall or overspeed conditions. A pitch mode (pitch hold) does not do that at all.
As for running out of steam, that happens if the pilot doesn’t know at what speeds to climb. Clearly, the AP follows the same principle of any automatisation: garbage in – garbage out.
