Need help with a flying boat

B

Bill Kestell

Charter Member
I ported the Sikorsky S-43 over from FS9 to FSX and all's well ... except:

Every other one of my flying boats will slow down nicely once they touch the water, but not this one. Even with full flaps, props to absolute minimum, throttles back ... it coasts ... and coasts ... and coasts ... and coasts.

Now, I did reduce the prop value back from 1.00 to 0.80, and she stops (still have to do all the above). This is not a good solution as it greatly impacts the cruising and top speeds.

I just can't seem to find out what value in the Air CFG file needs to be adjusted to bring it's performance envelope into line.

Any ideas?:dizzy:
 
Which Sikorsky S-43 are you referring to ?? The FS2004 model by George Diemer or the one in Lynn and Bill
Lyons "Golden Hawaii" scenery package ??
 
Bill Kestell said:
It's George's Sikorsky.
Click to expand...

It sounds like your not having any effect from the drag of the hull. Try the parasitic drag or the gear drag. there should be a value for it some where. now I'm not too familiar with FS2004 or FSX so I'm not sure where in the CFG or AIR file it would be with those. Thats just a direction to look.
 
Water Brakes

Bill,
What your are looking for is not 'Documented' (ie: not in the SDK, for air file, as there is no SDK for air files (hehe)). But I digress. You need to trial-n-error (reload default C-172, then reload aircraft you are working on, for changes to take effect) the SPOILER DRAG. You can then use the SPOILER for 'water brakes'.

First go to 'Aiplane Geometry' section of aircraf.cfg and find 'spoiler limit'. Make '59.989' (default value). Then go open air file, go to section 327, and make 'spoiler available=1' (true). Then go to air section 1101, Flight Dynamics and find 'Spoiler Drag=xxx'. Make it 1000 and go try. You might need more. Make it 2000 (no need to do small increments-bracket it for final value). Then is nothing works, make drag '= -1'. It will stop it dead in the water-guaranteed, so be sure your are wearing your life preserver (hehe).

I also have a tip for 'steering' when on water. You don't need to use the 'water rudder'. You can add a value of 30.000 to type 4 contact points (floats) under 'sterring ratio' column, FOR THE REAR MOST CONTACT POINTS (the furthest back 2 (if you have 4 or more). Works SMOOTHER than 'Whata-rudder' (type 5 contact points). I comment OUT (with '//') the 'type 5' lines, and add:
point.2=4, -24.000, 5.000, -1.990, 19600, 0, 0.512, 30, 0.200, 4.5, 0.800, 0.0, 0.0, 4, 0.0, 0.0
point.3=4, -24.000, -5.000, -1.990, 19600, 0, 0.512, 30, 0.200, 4.5, 0.800, 0.0, 0.0, 4, 0.0, 0.0

Notice the compression ratio values (0.200, 4.5, 0.800). Sound s/b =4 (for water loop). You can try these tips. Can't hurt and you just might like the result(s). Cheers.
Chuck B
Napamule
 
Had this problem with porting over Dave Moly's Walrus. Eventually modified the the aircraft.cfg so that it could be used on both FS9 & FSX.

Look back in the archives here for 'Walrus in FSX', post #74, although the attachment link does not work unfortunately, it might be worth reading earlier posts to get a lead.
IIRC C of G height, contact points & most of all minimum engine power made it FS9 & FSX acceptable. Crash detection OFF & realism reduction was also necessary.
HTH
Keith
 
Well lets see if this works. This is from post #64. I wish I had a copy of FSX. I'd try to do some testing for you. Saddly I don't. I would look at the entire thread. There was alot of info exchanged. I hope your able to get everything working right.

fleurdelys said:
Bonjour,

"Slow down and stop on the water..."

I also had this type of problem with my seaplanes. There is a solution but you will have to give some gas throttle advance when you start (just a few seconds to get the engine warmed up, then you can ease back on the throttle to its usual 1%). It resides in the following cfg section:

[Piston_engine]
power_scalar =1.00
cylinder_displacement= 125.0 //195
compression_ratio= 7.00
number_of_cylinders= 9
max_rated_rpm= 2050 // with 4 bladed prop. 2475 theoretical max.
max_rated_hp= 750.00
fuel_metering_type= 1
cooling_type= 0
normalized_starter_torque= 0.50
turbocharged= 1
max_design_mp= 35.00
min_design_mp= 10.00
critical_altitude= 4000.00
emergency_boost_type= 0
emergency_boost_mp_offset= 0.00
emergency_boost_gain_offset= 0.00
fuel_air_auto_mixture= 0
auto_ignition= 0
max_rpm_mechanical_efficiency_scalar=1.00
idle_rpm_mechanical_efficiency_scalar=0.65 //1.00
max_rpm_friction_scalar=1.2
idle_rpm_friction_scalar=1.0

The change that I made is in the "idle_rpm_mechanical_efficiency_scalar" which I reduced to 0.65. You may try a little higher settings like 0.70 or 0.75. The right setting should be the one that will get the plane to stop dead in the water after a little surfing from landing in the water...
The setting that I tried does the trick !

Anyone found a cure for the elevators and ailerons freezing when I try to take off from the water ?

Cheers

Fleurdelys
Click to expand...
 
Guys ... MANY THANKS!
I'll play with her some more today and let you know what happens.

"Water" is, I'm told, a very tricky area and the lack of seaplanes/amphibs when compared to land-based aircraft means that there aren't nearly as many creators; hence less available information on what makes them tick.

I'm just now getting he hang of contact points, scrape points, float points and water rudder. Sure ain't like getting a land-based aircraft to have 3 wheels aactually touching the tarmac. I remember when THAT was a big issue for me!:biggrin-new:
 
Experience

There is no substitute for 'hand on' (and trial-n-error checking) when it comes to contact points. Why? Because the compression plays a role (as does 'ref datum') on if/how the wheels 'contact' the ground. Milton Shupe and company KNOW how gear will 'act' (compression wise) because they design the compression into the animation when the build the model. Thus, what 'works' for his models won't work for other models. Being there, done that. So you have to approach each model as if it was unique, and 'different'.

The 'trick' I use, which saves a lot of time, is to make a (Lights) section and enter the co-ordinates for the gear (or floats) and you can 'see' where the contact points actually are placed. Then do the changes and reload to see changes. Repeat. When you have placed the cnt pts, then you go adjust the compression values. Again, some trial-n-error involved. The 'default' values are '0.500, 2.5, 0.800' (just an estimate). The floats, for example, can be (my preference) '0.100, 4.5, 1.000'.

I have been messing with cnt pts since FS98. So I might be able to help you out, if you need some tips. One tip is to not use 'type 5' (water rudder). The steering on floats can be on rear-most floats and it works much better than 'whata-rudder'. PM me. We'll talk.
Chuck B
Napamule
 
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