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Modified Airfile for the -32 Series

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Skully View Drop Down
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    Posted: 06 Dec 2013 at 9:53pm

In an interest to make this excellent DC-8 the very best it can be, I've created a new airfile plus cfg for the -32 series.

With the help of AirEd and AirWrench I believe I've corrected the FDE issues that I noted and added as much feel and realism to the aircraft that I can.

The aircraft will no longer lift the nose at 70kts, at typical operating weights with one notch of flaps - V Rotate at 138 kts and the aircraft will fly cleanly away by 150kts.

Modified Flap Angles

Corrected high pitch angles at approach speeds that were making it hard to see over the nose.

Modified CoG

Modified stall behavior- the aircraft will now drop a wing and pitch down in an aggravated stall but will recover forgivingly.

Added "feel" to the airfile eliminating the "on rails" feeling we see in many FS aircraft. Add some turbulence for a good time!

I've tested these files extensively but I'm sure there are improvements that can be made. I welcome any feedback.

These files are for the latest full release of the JustFlight DC-8.

If anyone is interested in testing them,feel free to download and let me know what you think.

Please backup your original cfg and airfile the -32 series.

I could not see where Justflight has restricted anyone from modifying their airfiles (as they allow repaints) but if there is an issue just let me know

Updated Airfile and CFG

http://sdrv.ms/1hTdCrf

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yankeeromeo View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote yankeeromeo Quote  Post ReplyReply Direct Link To This Post Posted: 13 Dec 2013 at 5:28pm
Hello Skully,

Nice try, more stable in overall but now she's got a nose down tendency when in cruise flight, even with a heavy load on the backConfused
otherwise, that's better. Thanks.
Beer
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Skully View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Skully Quote  Post ReplyReply Direct Link To This Post Posted: 13 Dec 2013 at 7:12pm
Interesting because it should be level at lower weights and a bit nose high at high weights at cruise.
I can fix it though fairly easily if you'd like.
I did my "heavy" testing at 286,000 lbs TO weight and "light" testing at 40% fuel with the same load out at FL 320.
What do you think of the roll and pitch handling? Does it feel more alive- more like you're actually flying an aircraft through the air?

Thanks for the feedback!
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Deltahotel View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Deltahotel Quote  Post ReplyReply Direct Link To This Post Posted: 13 Dec 2013 at 7:58pm
I will certainly give these a try Skully.

Any chance you could look at the 146 and adjust the exaggerated nose high cruise attitude??? I have tried altering the C of G in the aircraft cfg, but clearly I haven't a clue because all I managed to achieve was a distorted VC view! Weird.
Dave H
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Skully View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Skully Quote  Post ReplyReply Direct Link To This Post Posted: 13 Dec 2013 at 9:17pm
Originally posted by Deltahotel Deltahotel wrote:

I will certainly give these a try Skully.

Any chance you could look at the 146 and adjust the exaggerated nose high cruise attitude??? I have tried altering the C of G in the aircraft cfg, but clearly I haven't a clue because all I managed to achieve was a distorted VC view! Weird.

Do you mean the BAE 146 that was made by CLS for Justflight?
If so, I don't own it. Wish I could help.
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Deltahotel View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Deltahotel Quote  Post ReplyReply Direct Link To This Post Posted: 13 Dec 2013 at 11:24pm
"Do you mean the BAE 146 that was made by CLS for Justflight?
If so, I don't own it. Wish I could help."

Yes, that one. Lovely sim in many respects, but I can't imagine The Queen cruising at 5 deg or more nose up - the drinks and the soup would look all wrong, and the external view does too.

But thanks Skully. Still have to try your DC 8 tweaks.
Dave H
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yankeeromeo View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote yankeeromeo Quote  Post ReplyReply Direct Link To This Post Posted: 14 Dec 2013 at 8:44am
Hello Skully,

I have to fly more, with different weight&balance config, different FL cruise etc... 
I did a short flight yesterday with your modifs, with a lightly loaded  DC-8, Take off was rocket styleStarthe roll & pitch behave much more better, feel more like the real machine...
2 pics showing the "nose down" attitude when cruising, confirmed by the Attitude indicator, too.
I don't have much free time on these days but flying this "new" DC-8 is on the top of my FSX listBig smile 
i'll give you some deeper feedback later.
Thanks again for your work.
Beer



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Skully View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Skully Quote  Post ReplyReply Direct Link To This Post Posted: 14 Dec 2013 at 3:44pm
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Deltahotel View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Deltahotel Quote  Post ReplyReply Direct Link To This Post Posted: 14 Dec 2013 at 7:35pm
Ok Skully, just had a very brief look mainly to see if I have swapped the cfg and air files properly.

I must have the new set, got it just after the time of your last post. I was at max AUW - just over in fact but the C of G looked reasonable. Initial impression was of seriously nose up attitude at all speeds, (and a huge rotation to achieve lift off) but I only tried it at low level. Just to be precise, in level flight at 250kts, 3,000ft, clean, she was 18 degrees nose up, and seriously nose up in approach config at 170kts (admittedly way over max landing weight). Didn't have time to get up to cruise levels, and no opinion yet on pitch and roll responses.

I'll give it another go at a more realistic weight/load,
Dave H
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Deltahotel View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Deltahotel Quote  Post ReplyReply Direct Link To This Post Posted: 14 Dec 2013 at 11:26pm
Sorry Skully, but that just doesn't work for me. The nose-up attitude in all stages of flight is 'orrible!

eg
The-33 in cruise, straight and level, 30,000ft, high AUW (295,000lbs), 300kts IAS, .78mach, was 10 degrees nose up.
At 260,000lbs, 308kts/.80M still 9 degrees nose up.
and in app config, level at 4,000ft, 175kts, flaps 23degrees, gear down, still 16 degrees nose up.

and for comparison the unmodified -21 at 30,000ft, similar weight at 308kts/.80M is just 1 degree nose up and looks and feels right.
... and in similar approach config, level, just 2 degrees nose up.

Best of luck - I couldn't do it. Best mod I've managed was to reduce the flap travel speeds.


Dave H
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Skully View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Skully Quote  Post ReplyReply Direct Link To This Post Posted: 15 Dec 2013 at 3:47am
Ok back to the drawing board because I'm not seeing this in my sim.
Something must not be translating correctly to your aircraft.
I will look into it.
Thanks for checking it out anyway.
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Deltahotel View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Deltahotel Quote  Post ReplyReply Direct Link To This Post Posted: 15 Dec 2013 at 10:45am
You're welcome.

I'm not entirely certain what you are trying to achieve. If it is the view over the nose on approach, then in real life raise the seat (in the sim, change the eye-point). If you want to change the fuselage attitude for any given wing config, whether in high level cruise or low on approach, in real life you have to rebuild the aircraft and attach the fuselage at a different angle to the wing! You can of course alter the wing lift and drag characteristics with different flap settings which will give different attitudes for a given flight path, which you have probably done with your slightly different flap angles per notch on the lever. Or alter the wing.

Changing the (fore and aft) C of G, if my creaking memory of basic aerodynamics still serves, won't change the fuselage attitude much - it will require elevator/horizontal stabiliser trim changes to produce more or less lift back there to maintain the balance (more with an aft CG, so a little less lift needed from the main wing to maintain the overall lift balancing the weight of the aircraft, so a teeny weeny bit more nose down attitude, but relatively insignificant, and the drag factor has changed too. It will certainly affect pitch handling, which was another of your aims. However, it may all be very different in the simulation!

The roll response seems ok to me as it is, but we are all different and you clearly have the skills to modify. I think this aircraft, for real, would have been very stable, easy to hand fly. I guess you are looking for something more responsive.

See what yankeeromeo thinks before you take any notice of my input.


Dave H
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