Flyer59 wrote:
The DFC90 Autopilot in my Cirrus will not disconnect in light to moderate turbulence – and of course i have not tried it in severe turbulence.
With the R9 I have the DFC100. There is probably not a significant difference. When I was experiencing the bumps I was asking about technically everything was ok. I just wanted to know what I should be prepared to accept and when it is too much.
And now that I upload, those were the guys in question:
So far my experience with “I need to climb” was that ATC always wants to know my desired level. If it’s less than 2000’, the positive reply comes right away. When it’s more, I get “call you back”. I do have a hard time judging how much higher something in the distance is relative to my own altitude. I guess it takes a bit of practice and getting used to the perspective.
The DFC90 and 100 are the same autopilot, except that the 100 model is part of the R9 integrated glass cockpit and has no GPSS key (which they only put on the retrofit DFC90 because pilots were used to it from the S-TEC55X.
Other than that it’s the same autopilot.
There was a lot of turbulence in those? I wouldn’t have thought so!
Stephan_Schwab wrote:
I just wanted to know what I should be prepared to accept and when it is too much.
This is impossible to answer on a website as people have different perceptions of turbulence. Did you slow down? Were you able to maintain altitude and heading?
JasonC wrote:
This is impossible to answer on a website as people have different perceptions of turbulence. Did you slow down? Were you able to maintain altitude and heading?
I did not slow down and there was absolutely no struggle to maintain altitude or heading. Speed was 130 IAS at FL130.
The turbulence I’m asking about were a few heavy punches that served as a good reminder of why we have four-point seatbelts. Those clouds were not very deep either. The one I flew through took a few seconds to traverse and then I decided to jump over the others.
Stephan_Schwab wrote:
I do have a hard time judging how much higher something in the distance is relative to my own altitude. I guess it takes a bit of practice and getting used to the perspective.
I have no experience with it, but came across this App a while ago.
If you ever get a G-meter you will realise that fortunately pilot and passenger comfort usually intervenes way before you get anywhere close to structural limits.
I do have a hard time judging how much higher something in the distance is relative to my own altitude. I guess it takes a bit of practice and getting used to the perspective.
Look behind or past and to the side of the cloud. If the cloud behind is rising vs the worrying cloud you will top it(absent vertical development). If your worrying cloud is rising or stable vs background you are going to go into it.
Cool idea for an app!
I just wish there was one that yould determine the tops from below an overcast, or while I’m inside the cloud :-)
Another thing to bear in mind with the really bad clouds: they can climb much faster than you depending on the growth phase they’re in. Happened to me once, and it was very nasty but thankfully very brief.
Hard to gauge on the picture, but if these were say 20nm away, I’d probably would have asked for a climb early on; if unable, I’d have flown in the thinner bit in the middle and just asked for 20 degrees deviations right and left to stay VMC; my feeling is that I would have been ok going through it, but I would have executed the ice penetration checklist and be prepared to disconnect the AP and lower the gear if ias started to go over 150kts. I would also have done that only with some knowledge (from e.g. downlink weather) that there’s nothing more behind, although it looks ok from the picture.
Again, absolutely no reason to fly through that in your case. It’s just damn uncomfortable in there. This applies if you are alone. If you have passengers, don’t even think about going through that if there are alternatives. Passengers will hate you for that.
Regarding estimating cumulus cloud tops ahead, that is one of the exercises even very seasoned pilots will never master by 100%. It’s really difficult to get it right. Most of the time, one tends to underestimate the cloud tops, but just not always. The solution is just to be a little conservative and climb early, even if you doubt it’s necessary at all. Very often, going just 2000 feet higher will completely change your visual perspective at the stuff ahead and allow much better tactic planning.
I don’t have problems estimating the tops ahead (whether above my altitude) but what happens is that the convective stuff rises as the day progresses.
Distances up there can be great – often you can see 100nm – and in the 30-60 mins it takes the cover the distance, any convective stuff can rise by 1000-2000ft.
Normally I start a flight as early in the day as possible (to get the lowest convective activity) but that means that as the sun rises, everything starts to move upwards just as you are flying 
That IOS app looks fun but it seems a bit of a toy.
I agree about not flying through the stuff with passengers. In most cases, you can write off your passenger for ever if you scare them. And it doesn’t matter whether it is your wife or whatever; in fact I think it will be easier for your wife to just walk away from flying with you than for a stranger.
