Question re: Bjorn's MD500D

[Francois_Dumas 10]

It does indeed seem to sit pretty much 'backwards' and that rotor is almost horizontal I would say.... :-outta Francois :-wave________________________Francois A. "Navman" DumasAssociate Editor &Forums AdministratorAVSIM Online!email: fdumas@avsim.com________________________

[PeterR 9]

Thanks, Cal. Yep, those photos pretty much show that the rotor and skids are at the same pitch. So, now I just need to know how to fix the .mdl file to pitch the rotor forward a little.Hi Shoshana! Good to see you. Hope you'll be popping in some more.

[Guest Calb]

Fortunately, you can't "adjust" the .mdl file -- the original author (Bjorn) would have to make change to the original source file and recompile the .mdl.I say fortunately because I'm sure it doesn't take much imagination to realize what would happen if people could easily modify .mdl's.Calhover long and prosper

[Guest]

Hi Francois,All is well here, I'm having a really good time here I tell ya!!And being a BFU'er myself......I saw the pics....really cool!!!. The backward flying of Bjorn's model has been noticed by many, and as I had said before, it's the main flaw of the model, as the rotorhead should have been aligned with the chopper's CG, not to the skids, but hey.....maybe Bjorn will fix that in the near future...I surely do hope so for all the "chopper-jocks" !!! Wishes,Shoshana :-smile12

[PeterR 9]

True, true.

[PeterR 9]

I didn't know lots of other were talking about the rotor. I was just trying to understand what was happening. It's the engineer in me :-)Yeah, I hope he'll be able to adjust it. It's a great helo. I wonder if I should write him. Maybe he gets too much email about it already?

[Guest]

BFU/Hughes 500D Pilots....I have made a few modifications to the Distributed Weight and Flight Dynamics with the kind approval of Bjorn Buchner, the main changes are as follows:1. Aircraft Specifications ammended within AIR file to represent a more accurate flight model (original used Bell 206 data):-2 Dihedral - changed to help compensate for coning.3. Engine power output increased to better reflect H500 characteristics.4. Aircraft Gross weight reduced to reflect Hughes (fuel/passenger) 5 Pilots weight (165lb) CFG longitudal offset corrected.6. Distributed weight more characteristic of the 500.7. Hovering is now more realistic.The resultant changes should now provide a more accurate flight model with a very slight forward attitude during transational lift. I feel this now compensates for the slightly-forward tilt of the rotor blades (designed on the model) during lift. At first - I overexceeded weight distribution and the aircraft had too much forward attitude during lift!Known Problems: Roll Dampening still needs some minor work, Engine performance characteristics do not 'accurately' translate in FS2002. I flew the 500D around Chicago and she handles beautifully, flares great and hovers like a Bee!Anyway - try the files and let me know if you like them!For convenience, I uploaded to one of my old CFS sites - here is the link, just go down the page to LINKS and you will see them!Backup your original hughes500.air and aircraft.cfg files in your main BFU500D aircraft folder and rename them to hughes.orig and aircraft.orig and simply paste the two files in place of!http://www.angelfire.com/biz/cqradio/page7.htmlHappy Bush Flying:-rotor

[PeterR 9]

Thanks Terry!I was looking at the weight stations the other day. Based on the visual model, I came up with the following:station_load.0=0, 1.75, -1.2, 0.8 //Co-pilot (L)station_load.1=165, 1.75, 1.2, 0.8 //Pilot ®This assumes that the CG of the person is in their abdomen below the sternum.I'm curious how you arrived at the 0.300, 0.00, -0.050 location for the load.

[Guest]

Peter,Yes, at first, interestingly, it would appear that the pilot CG should be placed at a logical longitudinal point (based on the visual model - as you suggest) from the SDK's suggested reference datum. I tried this and it resulted in a 'dramatic' low-nose attitude! Then I realized that the SDK reference datums were, of course, all based upon fixed-wing flight-models and the difficult task was how to easily interpret MS SDK as applied to rotory-wing and the very precise CG extending down below the mast - By simply adding weight to the suggested 'stations' therefore wouldnt work in this (Hughes) example - because, if you added the weight of 2 people (eg 330lb) where logically the SDK suggests the stations should be, the amount of cyclic necessary to overcome the uneven CG would be totally out of limits!As a result of this excercise, I arrived at the figures shown, and this seemed to work out fine!... Of course, having said all that - we as helo-flight-modellers, are conflicting to some degree with MS original aircraft-container, which (as the default) sets the 206B realism-scalar to a minimum, and this sets the 'general scene' - which 'technically' is supposed to make the helicopter easier to fly.... in actual fact, the more realistic we make our model - by changing FD values - the harder it 'technically' would become to fly, so 'go figure!' :-hmmmI mention this because the 'original Hughes air file' is (like many helicopters) was based upon the 206B flight dynamics - which, in turn was based on earlier FS fixed-wing air files - With the recent phased introduction of the SDK's we are in a much better position now to adjust the flight dynamics and aircraft models to be more representative of the real thing - So, do we want the real thing???The 3-D modellers - like Bjorn who produce such excellent visual models (as the H500D could (if they so desire) now offer to leave the fine-tuning of the helicopter FD up to the individual's flying-application for the particular helicopter?Anyway, I now have the beautiful Hughes 500D engine warmed up and I think I want to go picnic on a nice Bahamian beach :)Happy Flying:-rotor

[Guest]

...For better convenience - I have also uploaded the files (Hughes 500D.zip) to Frank's site and it should show up on there in the next day or so.... I will then REMOVE them from my OLD CFS SITE.

[PeterR 9]

Hi Terry,I see what you did, now. Thanks. Sounds like a bunch of things need adjusting in the air file to make everything work out correctly, including the load stations.My vote is to lean toward the side of realism rather than ease of use. I have lots of games that let you fly helos but they're games, not simulations. As a result, they focus on gameplay rather than the realism of the flight model.

[Guest]

I saw Bjorn yesterday and I asked him about the chopper flying backwards.He said that I(and anybody else that wants to) should tweak the .air file.+

[PeterR 9]

Did he happen to say how?

[Guest]

I saw Bjorn last weekend and he agreed with me,the visual model has nothing to do with the flying characteristics in Flight Sim.He said that the .air file /aircraft.cfg need to be tweaked.

[PeterR 9]

Yes, but how?