Eric Dantes' DHC6 nose diving

[Ivaneck]

LAST EDITED ON Nov-13-02 AT 05:39AM (EST)[p]Hello,

More or less a week ago, I downloaded the Twin Otter from Eric Dantes. Is a marvel, beatiful, very detailed, and in my layman's opinion, it flies very well.

But when I start a fly with it in a typical airport for this type of plane, Lukla Nepal for instance, or if I drive it outside paved surfaces, the plane softly ends with its nose on ground, with engines stopped. No crash, only this.

I wrote the author reporting this issue, but now I'm not sure if this is a question of the design, or a problem exclusively mine. Before this post (a couple days ago), I asked here about this, with no response from anybody. I'm the only person with this issue?. In this case, at least I would like to send my apologies to Eric.

Thanks in advance,

Joan Coll
Barcelona, Catalonia

[Kihew]

Ola!

Hmm what I think that happens is that you may have "broken" the steering wheel, as you say you were taxiing on rougher ground. When that happens the nose drops and the engines stop (maybe simulating the propellers hiting the surface?)The problem must be a fragile steering wheel, something that can be edited in the plane's CFG file. As the aircraft is supposed to be a bush plane... I had that same problem on the latest Shorts Skyvan.

Hope it helped

Rui
Lisboa, Portugal

[Ivaneck]

Hello,

Rough, or not so rough... even in a gravel strip.

Nose wheel don't bump foolishly before sink, seems not a damping ratio problem. The plane dives his nose very softly.

Muito obrigado, Rui

Joan Coll
Barcelona, Catalonia

P.S.: Nobody can drive his Otter outside runway, and explain me if same thing occurs?

[Ivaneck]

I'm feel a bit ignored...

:'(

AKA <bump>

:-)

[JohnHamilton]

Salute Joan,

This Air Moorèa is a real beauty.

I don't quite understand your problem but would like to help.

I flew the craft from St Maarten to St Barthélemy in the
Caribbean using Chris Wilkes scenery. I haven't flown a
turbo' for some time so it took me a while to adjust to the
sensitivities of this little "sparrow". I flew IFR using
the autopilot which I disengaged at 2000 feet at approx'
9 NM from the airport.

She behaved perfectly on landing.

I did notice that you have to "tweak" your propeller, power
and fuel settings. They appear to be very sensitive.

I'm going to try her in Polynesia (Bill Mechiar's scenery)
which may mirror your particular problem.

Will report back if I can be of help.

Salutations, John Hamilton - Los Angeles.

[Ivaneck]

Hello,

> I don't quite understand your
> problem but would like to help

1) Problem is very simple, below I try to explain it again.
2) I'm very grateful to you. :-)

No problems when flying. It flies very well. No problems either when taxiing over concrete, or asphalt, it rolls perfectly. But try to start a flight on an airport with a gravel strip, Siglufjordur, Iceland, for instance (the first non-paved airport I remember now). The ICAO code is BISI.

Then, start the engine, and apply a bit of throttle. Or a lot, it's the same. Airplane rolls well, or ends with its nose biting the dust? In my case, after this, it needs sticking plasters to cure its nose... :-)

Problem is not depending of sceneries used, it depends of the type of surface. And is annoying because, just as Rui commented, is a bush plane. Non-paved strips are an everyday occurrence for it.

Thank you again, John.

:-wave

Joan Coll
Barcelona, Catalonia

[napamule]

Hi,
Did some 'tweaks' on 'Contact Points' section of ac config for the Skybus DHC6. On 'point.0' (nose wheel) change 1600.000 value for value 4 (5th one in, as value starts with '0'for 1st one in) which is 'Impact Damage Threshold' to 11600.000. Also value 10, 'Damping Ratio' from 1.043 (VERY critically damped (NOT good on a nose wheel)) to 0.774 (medium damped). This, and changeing value 3 (4th one in) from -4.800 to -5.300 (to expose more rubber, as wheel sunk up to rim, and really digging into surface). Now you should be able to go 'cross country'(I did) at 12 kts, with no problema. Hope this helps.
Napamule
ie:'Napa (auto parts) mule (delivery truck driver)'

[Ivaneck]

Hello,

I'm reluctant to tweak contact points by myself, not experiencied about this sort of things. Once at home I will try your settings, thank you very much for your help.

Is a beatiful girl, this Otter, don't you?. She deserves this "efforts".

Best regards,

Joan Coll
Barcelona, Catalonia

[JohnHamilton]

LAST EDITED ON Nov-15-02 AT 09:30PM (EST)[p]Hello Joan,

I tried French Polynesia (Bill Mechiar's scenery) and
had some experiences with this "oiseau".

The suggestion of changing the contact points is a solution.

What I did was to disable "crash detection" in the options
menu. The plane "bounces" a lot and you will see a lot of
"dust" here and there but you'll get her to the runway.
=======================================================

0.0. Taxiing is difficult. Throttle/brake ad infinitum etc etc....Difficult to control. Any suggestions?

1.0 Also I noted that with certain flights I would lose
airspeed at a rapid rate even when in autopilot mode during
the climb and also in cruise.

I'm questioning whether this is because of the initial "rate
of climb" and "trim" at takeoff? What is the ideal setting?

I changed the "panel" and problem 1.0. disappeared, bizarre!
============================================================

Trust that you will "enjoy" her eventually.

Buenas Noches. John Hamilton - los Angeles.

[napamule]

LAST EDITED ON Nov-16-02 AT 03:39AM (EST)[p]LAST EDITED ON Nov-16-02 AT 03:37 AM (EST)

Hello,
Yes it's a very good looking AC, and a Frame Rate hog as well (well, just a little more than usual, for DHC-6's).

If you can open notepad, and use delete, and/or double-click to highlight, and then enter the (new) values (leaveing the comma alone) you should not have any problema. Look for legend ('//pt.0-type', etc) in other AC's cfg (3rd party), then 'copy' and then 'paste' just above the 'Contact Points' entry, for quick reference. Then just do a 'save'(of cfg) when you are finished 'editing' it.

The throttle has a slight 'delay' to it: wait it out, and adj as needed up or down (patience is a virtue-but it also causes ulcers (haha)). No RPM gauge, or trim pitch gauge-I am going to have to get a NEW PANEL for this animal! Also, the engines get 'out of sync', erratically,and on their own (?), and not what one wants when landing.

But, that's the challenge, and the entertainment value of FS: DEAL(ING) WITH IT!! (ha) Will ck back here for progress.

Lot's of Luck,
Napamule

[Ivaneck]

Hello,

Napamule, I'm sorry to say that no luck with your tweaks :-(.

With Vertical Position set to -5300, the plane appears better based on ground. I leaved this parameter like you advised.

From MS SDK, Aircraft Container System: Damping ratio: ... and values greater to 1.0 might also cause instabilites by being over-damped. Thus, your value of 0.774 seems also a much better choice than the original value of 1.043, and I changed too.

Kidding a bit: my friend, with a Impact Damage Threshold of 11600 ft./min. perhaps you will could land the plane in a VTOL way, and after a spin...


http://www.flightsim.com/dcforum/User_files/3dd7df3e2a048c6b.jpg
:-) :-) :-)

Looking and trying, and after reading the SDK, I tried to increase value 8 (Static Compression) from 0.166 to 0.300... and it works!. Seems that with the original value the damper is too stiff. With this new value, the plane can roll everywhere with no more nose gear collapses.

So, here is my current point.0 line:

point.0= 1.000, 19.583, 0.000, -5.300, 1600.000, 0.000, 0.568, 44.100, 0.300, 2.500, 0.774, 0.000, 0.000, 0.000, 0.000, 0.000

Hope this can help people with this problem.

John, you're right, taxiing is difficult, and only solution I found is drive carefully, anticipating things. And yes, it seems very sensitive to trim settings. Perhaps with more practice... at this moment, I only have one or two hours of flight with it, and even not used autopilot.

I'm very grateful guys for your attention and dedication.

Sincerely,

Joan Coll
Barcelona, Catalonia

[napamule]

Hello,
You're right-11600 damage threshold IS 'too much', and I realize that, but desperate times makes for desperate actions (jeejee)- and I WILL try VTOL 'aproach', and 'harrier' land on the nose wheel, just to see if it will 'take it'. (jeejee).

I am not a purist, and I SHOULD use the SDK guidelines, but they (SDK/MSoft) are unable to guide some of those designers,as far as the 'model' is concerned, and how it effects the final product (ie: air worthiness of AC).

I will use your 'pt.0' values-thanks for shareing-I am still learning (everyday). I use 'flight tuning' in cfg, AND reduce down to 5% sensitivity of joy, and increase to 90% the 'null' setting. Again, it MUST be the 'model', and it's 'hard wired' parameters, that cause the exegerated trim, etc. Si, or si? IMO.

On taxi problem-again-I hit F4, and wait 2 seconds or so, then hit F1 AND then quickly hit F3 3 or 4 times (usually levels out at 10-12 kts). I then use the differential brakes, and rudder, to turn, and the brakes to slow. Works for me!

Best Wishes,
Napamule
Salinas, Ca

PS: Good luck cleaning that oil spill of your coast. Will take 10 years? Hell, we should make big ##### planes to transport the oil. At least they can clean oil off of dry land a lot easier than off of water, in case of a crash. Landing? Would simply drop (jettison) the 'containers', unto 'oil fields'(resovoirs)(of course 'damping ratio' on containers would inevitabley have to be 'tweaked' (jeejee))

[Ivaneck]

LAST EDITED ON Nov-20-02 AT 01:44PM (EST)[p]> I am not a purist

And I am a perfect layman :-). And you have reason about the nature of the info supplied by MS. After reading it, it's also needed to do experiments, use trial and error method, always trying to draw conclusions... often wrong. Is a common denominator from all of us.

Thanks for relate us your tests, with time I will take a look to them. About trim sensivity, no idea if the model 'embedded' in the .air file can have influence. Have you tried to tweak elevator_trim_effectiveness, in {Flight_tuning}? It's set to 1 (100% efective), perhaps a value of 0.90 (90%) or less can help. (Another thing to try, how many! :-))

Talking about taxiing, I use a very similar method, but using the joystick throttle lever, no FKeys. Full, idle, a bit, and then adjust depending of the speed obtained.

Joan Coll
Barcelona, Catalonia

P.S.: I think isn't my coast, i believe it's our. With this deliberated human incompetence that, as a whole, we showing, all us come off worse, all us are the victims. The case of this ship is only an example of our stupidity. It's frightful... what future will wait to us?. :-(

I'm not feel restrained to my native land, rather I think in myself as part of a whole. I have Salinas in my heart, someone called Steinbeck stuck it me :-).

> At least they can clean oil off of dry
> land a lot easier than off of water, in
> case of a crash

... and oil contaminate terrain and aquiferous ... I'm afraid is a problem without solution, like treatment of radioactive waste, hope hydrogen cells technology take preponderance soon. Relating aircrafts with this type of problems... perhaps a solution for a broken oil tankers is a dozen of missiles... in short, all that fuel would end burned, isn't? (what an use of 'militar' technology! :-)).

What a macro post scriptum... sorry for this pain.

[napamule]

Your are right Joan. (Te entendi lo que quieres decir=I understand what you are trying to say). It IS a small world, and we are all part of it.

We struggle each day to survive, and forget to look ahead, afraid of the unknown. Steinbeck was very insightful-of 'Mice and Men' and all that. He hated the premise that 'everything is ok-as long as it's for a dollar'. We play God. We 'fool' Mother Nature. And we sell what is not even ours (the air, the water, and the land) for a dollar. What can I say.

Lot's of luck. Keep 'hacking' them 'cfg' and 'air' files-keeps you busy, if nothing else (heehee).

Hasta La Vista,
Napa

[elcamino]

In light of all this, which setting do I mess with in the a\c.cfg to raise the mains back up onto the runway?

http://www.flightsim.com/dcforum/User_files/3de44aed60d0cc38.jpg

About half the rubber in buried.

http://www.flightsim.com/dcforum/User_files/3daf49ac22ec31a1.jpg
"Are We Having Fun Yet! & Happy Simming"
pSsT! Never skydive from your flight simulator!

[Spongey87]

I suppose the tires need replacing?


Don't call me weird, call me spongey.

[napamule]

Hey Jerry,
Don't know if your're 'TALKING TO ME...Talking to Me..?'(hehe). It would be the 4th value in (after the '='), in pt.1 left wheel, and pt.2 right wheel. The value is -5.100, or such, and to raise the 'tires' you increase (Yes, not logical, but..): like to -5.600, which is increase of .5, or 1/2 ft, or 6 inches. BUT..the wheels may be off the ground (related to 'pitch' setting) as you go down rnwy on takeoff. Or when you brake hard, they will also be off the rnwy, but it's a trade off. Hope this helps. I myself hate to see them 'flat' tires. Once in the air, it don't matter. I do some 'instant replay' of my taxi 'tech- nique', and it botters me (a little).
Best Regards,
Napa
PS: I see you do remote control AC's. Nice. FltSimming takes the 'edge' off, I suppose, eh? (Just got on (11:30 pm PST), so this will be 3 hours late, at least, but there's always manana.)

[napamule]

Hey Jerry,
Might as well include the section ('Contact Points'). See below.

//0 Class
//1 Longitudinal Position (feet)
//2 Lateral Position (feet)
//3 Vertical Position (feet)
//4 Impact Damage Threshold (Feet Per Minute)
//5 Brake Map (0=None, 1=Left, 2=Right)
//6 Wheel Radius (feet)
//7 Steer Angle (degrees)
//8 Static Compression (feet) (0 if rigid)
//9 Max/Static Compression Ratio
//10 Damping Ratio (0=Undamped, 1=Critically Damped)
//11 Extension Time (seconds)
//12 Retraction Time (seconds)
//13 Sound Type

[contact_points]//(LOOK FAMILIAR? THIS IS IT)
// 0 1 2 3
point.0=1.000,19.583, 0.000,-5.300,
point.1=1.000,-1.000,-6.417,-5.200,
point.2=1.000,-1.000, 6.417,-5.200,
(left out the other points,and values past no.3(vert.position), but this should cover it)
Napa

[elcamino]

Thanks for the info. That set it right.

Where do you find all these settings? I often wondered if there was a site, book, text file
or whatever that tells what all that tells what all thoses numbers in the ac.cfg mean.

http://www.flightsim.com/dcforum/User_files/3daf49ac22ec31a1.jpg
"Are We Having Fun Yet! & Happy Simming"
pSsT! Never skydive from your flight simulator!

[Ivaneck]

LAST EDITED ON Nov-27-02 AT 06:47AM (EST)[p]Jerry,

Microsoft's SDKs are the main source. Values related with contact points, f.e., are explained in the Aircraft Container SDK, with more or less detail.

Anyway, you will need to grin and bear it, and do tests until you get the desired results.

Regards,

Joan Coll
Barcelona, Catalonia

P.S. (Edit): You can get these SDKs in http://zone.msn.com/flightsim/FS02DevDeskSDK00.asp

[napamule]

Jerry,
Glad to hear you 'pumped dem aup'. There is so much to these AC's that there is 'rubber stamping', or 'plugging in' of pre-exiting values, to save time. It's understandable.

I start FS2k2, do a 'pause', then 'ctrl+enter' to reduce scrn size, then minimize it. Then I start Explorer, and nav to aircraft's config file, open it, make adj's, then minimize it, and Explorer too (BOTH, ok?). Then restore FS with 'ctrl+enter', and then 'p' to un-pause. You will then have to 'reload' the ac by doing 'alt', etc to just re-choose ac you just worked on, so that the 'new' config can 'take effect'. Your ac will be the one showing, so just hit 'ok'. I use 'spot view' to look at adj. I go to 'view', 'view options', and for DHC6 dial in '1' zoom, '60' distance, and '6' height. Then I use space bar, and hat switch to walk around AC. I move it, brake, turn, etc to see the 'results'. Not 'just right'? Repeat above. Hours will go by like nothing. I see you replied at 2:48 am last post. I used to stay up all night (starting after 'ole lady hit the hay, around 9pm). I like to work when it's quiet, and 10 to 3 is good for me.I am OFF to get the SDK (container section), so I can quote directly, and thus aquire 'credit' for solving some of these 'easy' problems. I may have to stay up days at a time to try to understand it-or maybe I'll set it up in Word, and do a 'search' on key word, and just plug the quote where it's 'required'. I can see me posting 1,000's of 'solutions', but in a subtle way, so as to make myself 'incognuito', but come out looking like the genius that I am. (Sarcasm, of course.)
Happy Adjusting,
Napa