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HELP.How do you trim this aircraft

Printed From: Just Flight Forum
Category: Just Flight Products
Forum Name: Constellation Professsional
Forum Description: Dedicated Constellation discussion area
URL: http://forum.justflight.com/forum_posts.asp?TID=13762
Printed Date: 25 Jan 2021 at 2:17am


Topic: HELP.How do you trim this aircraft
Posted By: doc289456
Subject: HELP.How do you trim this aircraft
Date Posted: 15 May 2010 at 4:10am
I am having all sorts of trouble trimming Connie, in particular adjusting pitch to maintain altitude & speed.

I am using autopilot and am attempting to fly at 10,000ft and no matter what I try I cannot maintain this altitude using the autopilot pitch settings. It will constantly drop altitude so I click the pitch up a notch and this will maintain altitude for a little while until the speed falls and then begins to drop altitude again so I adjust pitch again. This continues until the aircraft is at the point of stalling. I have tried adjusting mixture without success, even Ctrl-X to set it automatically.

According to the manual this plane should be able to fly with the following:

Cruise
For maximum cruise speed:
•     Level off and adjust cowl flaps to maintain temperatures in the operating range
•     Adjust manifold pressure to 31” and RPM to 2,300
For a fast cruise:
•     Reduce manifold pressure to 28”, maintain 1,800 RPM and close cowl flaps
For economical cruise:
•     Reduce manifold pressure to 25” and maintain1,800 RPM
For maximum range:
•     Reduce manifold pressure to 22” and maintain 1,600 RPM


Even at maximum cruise speed MAP 31" & 2300RPM (outlined above) this still occurs. The more economic settings are an impossibility. I even throttled up to 35" with the same results.
Flaps are up, wheels up, cowl flaps shut. No Cargo & Full tanks.

Am I missing something, have I set something wrong?

Is anyone else experiencing this?

I have not flown this plane for a long time and have just applied the patch. I do not remember having this much trouble before upgrading although my memory is a bit fuzzy.

Help.




Replies:
Posted By: JardY
Date Posted: 16 May 2010 at 6:23pm
I think it's quiet impossible to keep an altitude with this plane. I'm using VasFmc to autopilot the plane and to navigate with a "modern" system (FMS).


Posted By: doc289456
Date Posted: 16 May 2010 at 11:29pm
What is VasFmc??
I put this into google but am not sure whether I ended up looking in the right place.




Posted By: JardY
Date Posted: 17 May 2010 at 10:29am
VasFmc is a third party FMS and Free !

http://www.vas-project.org

Try the version 2, it's very interesting.

Take a look at this image of my computer using this program.
http://gallerycdh.free.fr/pf/vasfmc.jpg


Posted By: doc289456
Date Posted: 17 May 2010 at 2:04pm
That looks interesting, complex but interesting.
Maybe I'll give it a try.
I went to the website, and followed these links: http://files.vas-project.org/ - Home » http://files.vas-project.org/index.php - VAS Download Archive » http://files.vas-project.org/category.php?id=2 - vasFMC 2.x » http://files.vas-project.org/category.php?id=4 - MS Windows Standalone Version
Which brings me to a page which has links to xplane.org
Is this right? And if so, which file do I download?





Posted By: JardY
Date Posted: 17 May 2010 at 4:13pm
Yes, it's ok because the program is compatible with FS & XP.

You can download the program on FlightSim too : http://flightsim.com/kdl.php?fid=134545


Posted By: jimbo757
Date Posted: 19 May 2010 at 10:41am
Just Flight have produced a very creditable simulation of what a 1940's airliner would have been like to fly. The autopilot was cude and basic, so although it would hold heading regular input was needed to adjust pitch to hold altitude. It was a fact of life and quite often the autopilot failed completely. Imagine bashing across the Atlantic in foul winter weather for hours on end with no A/P. We should be thankful for today's modern aids and respect those who did it for a living(mostly successfully!) half a century ago.


Posted By: doc289456
Date Posted: 19 May 2010 at 2:50pm
Jimbo, I appreciate the authenticity of the sim, I realise that I will need to make fine adjustments to the pitch to keep the aircraft trimmed and I actually enjoy doing this, trying to tweak the pitch to get the best out of the aircraft.
But with my problem I can never make an improvement things just get worse & worse until I am going so slow & with so much pitch that I will eventually stall. The only way I can maintain any sort of altitude and speed is to have the Manifold Pressure up higher than around 43", I am sure these aircraft weren't designed to be flown like this. There is no way I can do the sorts of settings that are outlined in the manual.
Is anyone else finding this?
I have been through everything I can think of when flying without any improvements. Am I missing something?
Like I said earlier I don't recall having this much trouble before the patch. I actually used to fly Connie in Air Hauler and did so for some time. I don't think I would have done so if I had this much trouble. 


Posted By: jimbo757
Date Posted: 20 May 2010 at 10:51am
doc289456, I don't get it, unless it's a PC/software problem. I've reduced fuel to 1800kg in each tank which gives a A/C mass of 35000kg, which is approx max landing mass. This gives a livlier T/O performance and I can just do a quick circuit without exceeding max landing mass. I've also frozen the fuel so I don't have to worry on long flights. At this weight I've been able to climb to 25000' and maintain as a cruise remembering to lean the mixture(CTRL+SHIFT+F2) in the climb so its almost closed at cruise. I use 35" of manifold for all the climb and you need to keep increasing the throttle as you go up to maintain this until you reach full throttle. Unlike jets there's no surplus of power so maintain power on level off and accelerate to 175 IAS before setting the cruise power, then just small pitch changes using the autopilot are needed to keep altitude and the speed should hold.
I find the above works for me, so good luck.


Posted By: doc289456
Date Posted: 25 May 2010 at 1:17pm
Jimbo, well i have been flying the connie again a bit lately. I have so far been flying the c69 and, unless there is a difference between the c69 and the passenger models, it seems I must have been doing something wrong. Who knows what. But in this plane at least I have been able to maintain altitude & speed. Although anything below 31" & 2300rpm becomes really difficult. Will keep trying.


Posted By: Capt. Haddock
Date Posted: 30 May 2010 at 12:40pm
Don't mean to patronise, but you are leaning the fuel mix back aren't you? I find I have to cut the mix right back to about 25% if I hope to gain any altitude above FL150, and to about 50% if I just want to cruise along nicely at 10,000.
 
>^..^<


Posted By: doc289456
Date Posted: 30 May 2010 at 2:29pm
Capt,
Yes have been adjusting mixture back.
In fact I've gone back to realism settings and switched it back to auto mixture just to be sure. No difference



Posted By: doc289456
Date Posted: 02 Jun 2010 at 8:18am
Update, I have managed to cruise at fl20 at 28MAP & 1800RPM it took a long time slowly winding back the RPM to reach these settings It had heaps of pitch (ie nose was pointing way up) on full tanks. It leveled out nearly fully when under half full of fuel. I could not have achieved any of the more economic settings at this altitude maybe at a lower altitude??? will keep trying.
I must admit I have installed an autopilot  into the C69.
I did try vasFMC but it seemed too buggy and awkward to use.



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