AOA icing landing data

[Turbine777 13]

Hi folks, Just recently I finally acquired the needed virtual coin (in FSPassengers) to buy the J41. I have technically owned it for over a year but just now really starting to log some hours on it. I have run into several questions that I found answers for here, but one remains unanswered.To better learn high angle descents and of course throw in some fun, I've been touring Alaska. There are several great default airports with some rather intense approaches. Although not quite like Innsbruck, they have their moments. In the last few flights using real world weather, I have run into a few situations where I'm not sure when one would make the final call on which landing configurations to go with such as icing and speeds.For example, I was descending from altitude approaching PAJN. At FL140 I had full anti ice on with lots of moisture and temps consistent to about -8°. Icing conditions remained until on final at approximately 1000' above DH. I was still in moisture with light rains by this point and temps just getting above the +10° limit. With so much going on and little time being new to this bird, I left it as is and continued with my approach and landed using the defined speed card for AOA Icing landing. My reasoning (justification) was that although I was finally in temps above 10° that I probably could have still had possible icing and again, less 2 minutes before TD at this point. Since, I have run into enough of similar approaches that I wonder what is the correct procedure. Is there a certain time that there is a final decision made? I can only guess that real world pilots go by what's on their lap (or kneeboard and such). Add enroute weather updates but all of these things change I'm sure too. So is there a time where the pilot commits to making a decision on Icing or no? Does he ever change his mind, thus changing the landing type/speeds during approach or is this more a company SOP? From reading in the tutorial that the company spent as much as they did on the derated thrust book, I can only think that there might also be an SOP to not use this sort of landing if not absolutely necessary as well, and therefore a set time or distance from arrival when to decide on this and stick with their choice all the way down. For now I've been making this decision at IAF and sticking with it, hence only needing to change the speed bugs once, although I also still leave the book open to reference other speeds just in case.Thanks. Loving this plane lately and it really adds a sense of accomplishment to landing at the correct speeds (especially when the GS is +5°).Picture is descending into PAJN in Alaska. I took the liberty of trimming a few mountain trees during that approach, but have gotten a little better at steeper descents since then :(

[sheepfu 3]

Dan,Since no one has answered your question with an official answer, I will tell you what I typically do. When on approach and I drop out of icing below 10,000 ft. I typically do not adjust the speeds on the PFD. I will look at the chart and make a mental note of the VREF, but I don't take the time to change it as I am usually in the process of trying to fly the approach. However, I do turn off the engine anti-ice when I am able after dropping out of icing conditions. This gives me maximum power to go around in case I mess up the approach as happens more often than I would like when flying Alaska.

[Turbine777 13]

Thanks Branton, Hearing what others do it good as well since it let's me know I'm at least thinking of it correctly. It looks like I "stumped the chef" on this one although I know why it will go unanswered. I'd like to hear what others do as well. There aren't any wrong answers I don't think, at least not how I'm looking at it. I agree with having max power for GA but it depends if still how long I've been out of the elements. I have the APR armed for more juice should I need it and actually just did yet another go around x2 trying to land at a rinky dink airfield in Canada in the mountains with no approach available. Both go arounds were due to low clouds but I had full anti ice going and no issue with power (in fact I never used the APR either). Real world might be a lot different though ;)I do the same as you and make a mental note of speeds and often leave the book open for a quick glance now and then once on approach down to TD. Like you, I normally have to many other things going on to dial them in for reference since it looks like that's all you dial them in for (at least by the time you're on final). It just seems like there would be a safe margin (there normally is) as far as an SOP for when exactly to make the choice and stick with it. If nothing else, for engine life. For now, I'll stick to final decision at IAF. If I have moisture and in the freeze zone, I'll keep all the AI on, if passing the IAF I am in the freeze zone but no moisture, I'll shut them off.

[CapP 0]

Remember that airframe de-ice should be turned off before 200 ft above the runway! It's somewhere in the manuals.

[Turbine777 13]

Thanks Pieter, It always is (at least for me) since it only has the constant manual activation and auto only runs for a few seconds. My hands are normally full still during the last couple miles so in this one case, I'm glad it only runs for such short spurts, otherwise I'm sure I'd forget to shut it off once in a while. I think the last time I've ever activate that was just before reaching glideslope intercept but yes, due to the change in the boots I'm sure you wouldn't want it during landing. At that point I'm normally deploying the parachute to help slow down anyway ;)

[CapP 0]

Yes, i think that's one of the most annoying things of the js41: constantly pushing the airframe de-ice button. In icing conditions i press that button and at the same time start the timer in my Saitek yoke. After 1 minute i press the button again. Quite a distraction while flying the approach! With fs2crew you can ask the pnf to do it, but it's still annoying (and dangerous if you forget to give the command every minute).

[Turbine777 13]

I've heard a lot about FS2Crew and the J41 and will get it most likely once I have the funds. I have an older version for the queen. I don't find all the tasks that unbearable but an extra set of hands would be nice. I can't do the voice one though since my current available sim time is after my roommates have gone to sleep. I like flying, but don't want to watch my computer fly out the window which is probably what I would do in their situation :(

[Houghton11 12]

Yes, i think that's one of the most annoying things of the js41: constantly pushing the airframe de-ice button. In icing conditions i press that button and at the same time start the timer in my Saitek yoke. After 1 minute i press the button again. Quite a distraction while flying the approach! With fs2crew you can ask the pnf to do it, but it's still annoying (and dangerous if you forget to give the command every minute).

I think you are confusing "Anti-Ice" with "De-Ice".On the J41, airframe de-ice is provided by pneumatic rubber boots located on the wings, horizontal and vertical stabilizer. High pressure and high temperature air regulated to around 20ish psi is used to inflate the boots.You see, unlike pneumatic or electrical "anti-ice" systems, the principle behind pneumatic boots is the change in shape of the leading edge and 'shed' the ice off. It's not meant to heat up like anti ice systems to prevent the formation of ice, only shed it off once it has formed.This, is why you have the Automatic de-ice cycle. You only use a pneumatic boot system when there's a appreciable amount of ice formed on the wing (I know it sounds bad). If you use it too frequently (every minute as you describe above), you run the risk if the ice forming on the enlarged boot, then there's no way to shed the ice off...bad! The auto de-ice does cycles through the different boots (inboard outboard wings..stabs..etc) to reduce this risk, and not bleed too much air from the HP Bleeds off the engine.There is a ever-continuing debate in aviation regarding how much ice one should have before activating the boots. In all cases, just follow the book..haha.

Of course, in severe icing there's little one can do sometimes:As for turbine777's original q, I think you have the right attitude about it. It's just another judgement call one has to make! Of course, the easy answer is in any suspected icing conditions just go with the high speeds, but in the region's you're flying, it becomes a bigger question when considering limited runway, steep approaches..etc...I'll see if I can ask some old J31 drivers around how they approached that matter.

[Turbine777 13]

Very cool, thanks a lot Patrick. Great info and seeing it in action is always a plus. Soon as I read you mention how it was saw the possible hazards of using it too much. Oh and yes, please let me know if you get any info how the J31 pilots do it. Once I get it fully in my head and fully understand it I tend to retain it better. It's like doing the head tilt that a dog does in understanding turbo props at first. Once I learned what was going on during the cycles of an engine, mixture became so much clearer, then in learning turbo it was again easy to take it all it.As a side note, I do like how the ice detect was modeled. Of course no one (not even the pilots from what I read) like how often it goes off, but I have now done several flights and completed a tour around Alaska and as far North as I could go, traveled all over Canada and just returned to KBOS last night. In several of these flights I noticed I would be at about -7 (basically in icing conditions) but without moisture around, then as soon as I entered a cloud the ice detect went off as I would expect. I know in the real world it may take time but to see something like that could be simulated as close as it was in FSX is impressive regardless. Thanks again.PS. Nice pic also. Someone might want to check that tire though, it looks a bit low :(

[CapP 0]

I think you are confusing "Anti-Ice" with "De-Ice".

I am, or at least: I was. Thanks for this very useful information!