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PostPosted: Wed Feb 07, 2018 1:17 am 
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WB_FlashOver wrote:
1) A reciprocating piston engine, is a reciprocating piston engine, is a reciprocating piston engine. Sure there are many differences with stroke, bore, valve train layout, etc, etc. I understand now that airplane engines are created differently.
Well, yes and no. Of course, they are just reciprocating engines like any else. What is somewhat different to some other engines is that they are RPM-limited by load to a relatively narrow operational range. The designer essentially knows that the engine runs, for instance, in between 2000 and 3000 RPM always when it is under considerable load (never higher), that it is always operated at or above certain operating temperatures, that the RPM is changed smoothly, and say, that it is not used for engine braking but is under good loading when at speed. And so on. Then you can simplify and optimize ignition and valve timings, cooling, crank journal lubrication and whatnot. Material properties, fatigue and all that sort is of course just like with any other engine of similar metallurgy.

WB_FlashOver wrote:
2) I was always under the assumption that using full takeoff power is for safety sake, "Don't dilly dally, get her airborne".
That is one thing, but there is more into it. Using higher power reduces the time you spend at high power setting, low airspeed combination with your air cooled engines. Also, with many aircraft engines, if you are not using the maximum power, you are not allowing for the full-rich takeoff power fuel mixture, which is often achieved by specific enriching function enabled by throttle moving to the full.

WB_FlashOver wrote:
I also thought that the listed climb and cruise settings were considered to be the max, or do not exceed, settings. Not "use these or expect failure" settings.
Well, they are neither, but more like pre-plotted settings where the engines and the airplane operates more or less as designer wanted, and in a predictable way. Usually there are little reasons to invent one's own settings, if not for a specific purpose. (There are some few exceptions of course, and even some flight manuals give settings that...well, are rather interesting.)

-Esa


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PostPosted: Wed Feb 07, 2018 9:14 am 
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Another way to think about Aero Engines is to think of them as industrial engines. Indeed, this is why many of the most popular Marine and Industrial turbine engines are derivatives of Aero Engines. I wanted to work this into my last post, but couldn't get it to fit. :)

Anyway, if you watch Agent JayZ on Youtube (https://www.youtube.com/user/AgentJayZ) he works on aero-derivative industrial engines and their original counterparts (including converting some aero engines to industrial versions), you'll see that many of these engines run 24/7 for YEARS (tens of thousands of hours) at 100% power between overhauls and many only need the known wear parts replaced or repaired (i.e. turbine blades re-ceramic'd, carbon seals replaced, etc) and then they go back out for another 20-30 thousand hours of operation. In fact, there are turbine engines today that have gone 40,000 hours or more on the wing of an airplane before needing major work. There may have been the odd accessory or hose replaced, but beyond that, the most work it would have had is lubrication service (oil changes and re-greasing of certain bearings depending on the engine).

This is the main reason that aviation has moved to turbine engines. Even though they burn more fuel, they are infinitely more reliable. They also are now approximately 50% of the cost of a new airliner, so they had better be.

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PostPosted: Wed Feb 07, 2018 9:57 am 
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Though to be fair, airplane gas turbines are much higher stressed than most industrial ones. They are in that sense unlike aircraft piston engines that NOT using full power for takeoff is generally preferred with turbines, and has direct benefits in prolonging the hot section life.

-Esa


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PostPosted: Mon Feb 12, 2018 12:14 am 
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Well, I had to work Saturday so was looking forward to this morning to try the charted power settings. I departed Kampala, Uganda for Antananarivo, Madagascar. It's about a 6.5 hour flight and things were going great. I was really looking forward to seeing the report after the flight. About 15 minutes from touchdown ASP4 went absolutely MAD! :evil: :twisted:

At 8,000 feet and setting up approach for RWY 11 winds were 145 @ 04 but the plane was acting like it was being swatted constantly by a tennis racket. The IAS went from 180 to over 300 knots in level flight with power pulled way back so I put it in a 2000 foot per minute climb but the speed kept increasing. The thrashing continued, the passengers kept screaming and the crew kept grunting and grumbling. Needless to say I was unable to land. I ended the flight and will have to try again next weekend.

Very frustrated about the whole ordeal. After my 65 hour week I was so looking forward to a nice relaxing flight. I've had ASP4 go mad once before and I'm not sure what to do about it. A mate that was flying with me had the same issue with ASP4 and it actually over-stressed his aircraft to the point of crashing it (I had turned off Stress Damage in P3Dv4 after the last time ASP4 went mad). I was really looking forward to flying with the knowledge I have received from this thread.

Roger

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PostPosted: Mon Feb 12, 2018 10:12 am 
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WB_FlashOver wrote:
Well, I had to work Saturday so was looking forward to this morning to try the charted power settings. I departed Kampala, Uganda for Antananarivo, Madagascar. It's about a 6.5 hour flight and things were going great. I was really looking forward to seeing the report after the flight. About 15 minutes from touchdown ASP4 went absolutely MAD! :evil: :twisted:
Any thunderstorms or CB clouds in the area as indicated by local metars? I find these totally unrealistic and overdone in many cases using Active Sky. Also vertical drafts are poorly modeled, or at least still where when I last tested. This all needs one to throttle the settings in the program, and potentially to disable the "realistic" thunderstorms.

-Esa


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PostPosted: Mon Feb 12, 2018 9:08 pm 
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AKar wrote:
Any thunderstorms or CB clouds in the area as indicated by local metars? I find these totally unrealistic and overdone in many cases using Active Sky. Also vertical drafts are poorly modeled, or at least still where when I last tested. This all needs one to throttle the settings in the program, and potentially to disable the "realistic" thunderstorms.

-Esa

Yes, we had thunderstorms but not really what I would call thunderheads. Clouds were maybe 4/8, two layers, several thousand feet apart, both with lightning. Coming down to 8,000 was quite uneventful but at 8000 feet all hell broke loose. After my first couple of flights with ASP4 I reduced many of the settings due to terrible depiction of turbulance. It's seems quite manageable as I have it but this time it was just crazy. ASP4 was showing no warnings or shear in the area either.

Oh well, there is always time for another attempt at it.

Cheers
Roger

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PostPosted: Tue Feb 13, 2018 7:26 am 
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I'd recommend that you try to put some low figures to the maximum updraft and maximum downdraft velocities (I think these were set in feet per minute), and unticking the option for realistic thunderstorm drafts. I don't remember exactly what they were called but you should find them pretty easily. Then try to altering them back in game one-by-one in appropriate conditions.

In particular in Africa, I've noted that with default settings many places get unflyable rather easily, due to commonness of smallish cells developing into local CBs. Avoiding TCu and CB clouds doesn't work much at all, because the areas of where the AS tries to kill you extends unpredictably outside the visual clouds themselves.

-Esa


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PostPosted: Tue Feb 13, 2018 10:59 am 
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Esa is spot-on with his advice. A few years ago I could not make it from London to Ediburgh without a great number of passenger injuries due to AS injecting really over the top turbulence and wind shear. In the clouds was a nightmare, as you might expect. But even on the not so near periphery of clouds, the Stratocruiser was guaranteed to be almost uncontrollable.


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PostPosted: Tue Feb 13, 2018 11:54 am 
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WB_FlashOver wrote:
...ASP4 went absolutely MAD! :evil: :twisted: ... Very frustrated about the whole ordeal. ...

Roger


Make sure that you have Enhanced Turbulence turned OFF. The Connie hates enhanced turbulence. Then go and take a good look at your planned flight with SkyVector. Click on the little layers icon. Now click on the MRMS weather radar box. Right now, 16:45 Zulu, 2/13/2018, we don't have a lot of precipitation in the USA, but I see a nasty system near Sitka, AK and some precip near Minneapolis. Now click on the Turbulence box, then the Icing box. One at a time is best. Hmm... Might be best to fly in the Southern Hemisphere.

Check again that Enhanced freaking Turbulence is shut off.

Happy Landings! Oh yeah. I fly for fun. This goes for the Connie, also. Therefore, I fly with Career Mode off. All I have to do is make sure my cargo and my friends in back get down in one piece. Any complaints and I pay their airfare back home on a real airline. Like Aeroflot.

OK - I gotta go get some more coffee, then get together with Ernie to plan our second leg of GAAR 2018 flight.

Seeya
ATB

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PostPosted: Tue Feb 13, 2018 9:07 pm 
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Hello Gents,
I have made the edits that have been suggested many months ago. I tweaked a few other items as well and for the most part it has been fantastic. I really believe it was a glitch in ASP4 and the metars it was pulling from or the way it was interpreting them.

I will check out SkyVector shortly and see what it's all about. I was figuring that if ASP4 was going to input such turbulance it would have showed up on the map with Shear and Warnings enabled but it was showing nothing. The strange thing about this incident is that my speed was increasing and nothing I did was slowing it down, even a 2000 foot per minute climb.

Thanks
Roger

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PostPosted: Sat Feb 17, 2018 8:58 pm 
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Frustrated... still ...
So, today I got the chance to try the flight to Madagascar again. It started very well. In-spite of every fiber of my body screaming at me to pull the throttle back on take-off I held forward at charted settings (although part way down the runway I noticed my hand had pulled it back without telling it was going to do so). I still got airborne at 44"/2800 and pulled it back to prescribed climb and then held it 29"/2150-2200 for the cruise. I pulled back some for the descent into another storm like last time but kept power setting higher than my normal.

I had to restart ASP4 several times when things got to the point that parts were going to start falling off. After each restart of ASP4 things would be what I would consider realistic thunderstorm weather but within 10 minutes or so another restart was needed. When it got to the point that things were un-flyable I just exited ASP4 and landed. I have flown in many many thunderstorms and foul weather with ASP4 as I've circled the globe more than once with close to 160,000 SM on her but it's never been like this weather at Madagascar. SkyVector & ASP4 showed no severe weather, turbulence or sigmets in the area.

Anywho, sorry for long post. I landed and was excited to see my after flight report. To my dismay this flight is close the most costly I have ever had for maintenance. 5 hr 13 min and maintenance was $285. I've flown flights double that with that cost. Not really sure what's up with that. After flight report was all good, i.e. Everyone wants to be me - Like a big party - Aced the landing - They think I am a hero.

Is it possible that weather effects are being monitored by Accu-Sim and thus the repair costs from weather? Or am I still doing things wrong?

:twisted:
Roger

PS: ASP4 settings
Max Cloud Turb = 80, default = 100
Prevent TS when CB reported = ON
Multi Layer TS = OFF, default is off but is still producing multiple layers
Max wind Turb = 80, default is 100
Turb scale factor = 30, default is 70
Max wind shear = 30, default is 50
Enhanced Turb = OFF, default is off
Max down & up draft = 500, default is 1000
Realistic TS up/down draft = ON, maybe should turn this off

Are these close to what others are running?

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PostPosted: Sat Feb 17, 2018 9:26 pm 
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Thunderstorms are known to produce severe/extreme turbulence (which can result in structural failure), severe icing, and vertical drafts in excess of 6,000fpm. It might be possible that ASP4 is giving an accurate approximation of thunderstorm conditions. Are you flying right through the center of the thunderstorm clouds? Or are you deviating around them? Standard airline ops is to avoid the cells by at least 20nm, but this can be difficult when navigating around multiple storms.
Remember also that your Connie does not have weather radar (unless you have installed one), so modern? best practice is to avoid areas of "embedded" storms (storms intermixed with regular clouds = remain in visual conditions when thunderstorms are present).

Pretty sure takeoff map is 46".. you're almost there! Put those needles on the red lines! There are other phases of flight in which you should gently care for the engines. Now is the time for them to earn the price you paid for them. :mrgreen:


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PostPosted: Sat Feb 17, 2018 10:09 pm 
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flapman wrote:
Thunderstorms are known to produce severe/extreme turbulence (which can result in structural failure), severe icing, and vertical drafts in excess of 6,000fpm. It might be possible that ASP4 is giving an accurate approximation of thunderstorm conditions. Are you flying right through the center of the thunderstorm clouds? Or are you deviating around them? Standard airline ops is to avoid the cells by at least 20nm, but this can be difficult when navigating around multiple storms.
Remember also that your Connie does not have weather radar (unless you have installed one), so modern? best practice is to avoid areas of "embedded" storms (storms intermixed with regular clouds = remain in visual conditions when thunderstorms are present).

Pretty sure takeoff map is 46".. you're almost there! Put those needles on the red lines! There are other phases of flight in which you should gently care for the engines. Now is the time for them to earn the price you paid for them. :mrgreen:

I never fly through the middle of a thunderhead but when your destination is under the storm there is not much can be done except to use the open spaces between clouds. I do avoid them when possible, yes. I have tried the default ASP4 settings and they were not as bad as my last two attempts at landing at FMMI :shock: I now have things turned down quite a bit but have never seen anything like this cell over Madagascar that has been there for a week at least.

In many years of flight simming today was my first time of serious icing. I've had the pitot ice up before but today I actually had to run wing deicer and prop deicer. I always heard that icing of wings was not modeled. Well, paint me yellow and call me stupid :roll: now I know better. I have been using SkyVector and ASP4 for weather. They both showed no sever weather.

Cheers
Roger

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PostPosted: Sun Feb 18, 2018 9:55 am 
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Well, typically when the airport is directly under the thunderhead, you hold until the thunderstorm has passed or you go to your alternate to get fuel if you can't hold. Next month starts that season for us here in Wichita Falls and we'll be getting plenty of diversions from DFW whenever the storms roll through. :)

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PostPosted: Sun Feb 18, 2018 2:34 pm 
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CAPFlyer wrote:
Well, typically when the airport is directly under the thunderhead, you hold until the thunderstorm has passed or you go to your alternate to get fuel if you can't hold. Next month starts that season for us here in Wichita Falls and we'll be getting plenty of diversions from DFW whenever the storms roll through. :)

Yes, CAP, it could very well be that of all the storms I've flown into, this is the first time I've experienced this severe of a storm. I didn't have an alternate as the whole Island of Madagascar was covered with clouds and neither SkyVector nor ASP4 was showing severe weather when starting the flight. Anywho, I have sidetracked this thread with my whining about foul weather :roll:

I did another flight today with prescribed settings the whole way. I ended with great reviews. 2 hr 18 min, 697sm, $204 fuel, $121 maint. I did make one mistake that I know of but not sure if that is listed in the maintenance costs. I forgot to disconnect the GPU prior to push back :mrgreen: Whoopsydaisy!

My average costs after 194 flights are:
--$36.64 maintenance cost per hour
--$0.13 maintenance cost per mile
--$0.26 fuel cost per mile
--837 sm average per flight
--2.82 hours average per flight

Fun numbers to look at and looking at $0.13 per mile seems pretty darn cheap.

Cheers
Roger

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