PDA

View Full Version : Fsx acceleration Landing gear.



peter12213
May 5th, 2009, 14:40
does anybody know how to strengthen the landing gear of aircraft in fsx..any help much appreciated.
Its mainly for carrier aircraft as some have nose gears that are just to weak to deal with the landing!!

Milton Shupe
May 5th, 2009, 16:14
In the aircraft.cfg, Contact Points section, the nose gear is typically contact point.0=1, the 5th parameter reads:

5 (3200) Impact Damage Threshold The speed at which an impact with the ground can cause damage (feet/min).

The 3200 in this example is feet/minute speed above which damage is incurred.

Raise that number for more robust applications.

peter12213
May 6th, 2009, 05:25
In the aircraft.cfg, Contact Points section, the nose gear is typically contact point.0=1, the 5th parameter reads:

5 (3200) Impact Damage Threshold The speed at which an impact with the ground can cause damage (feet/min).

The 3200 in this example is feet/minute speed above which damage is incurred.

Raise that number for more robust applications.

thanks so much mate al giv it a try now ive been really gutted that some aircraft just can't take an arrested landing!!

peter12213
May 6th, 2009, 06:14
Unfortunately this fix did not work but thanks anyway!...i think its the hydraulic arm on the nose gear it compresses too much i need to find a way of making this stronger for carrier landings!!

cheezyflier
May 6th, 2009, 07:09
best thing is not to land like a bush pilot :icon_lol:

Hanimichal
May 6th, 2009, 07:17
hey peter12213 look what I do with default F18
http://www.sim-outhouse.com/sohforums/showthread.php?t=15754

Milton Shupe
May 6th, 2009, 10:15
Unfortunately this fix did not work but thanks anyway!...i think its the hydraulic arm on the nose gear it compresses too much i need to find a way of making this stronger for carrier landings!!

There are many things required to make a successful landing.

There are also many things required to find a solution to ones issue.

Give your specific information and we can all stop the guessing games.

Some helpful info would be answers to these questions?

What is the aircraft you are having issues with and where can it be found?

What is your approach speed and descent rate at landing?

What do your contact point data look like? Post it.

Are the crash points stated properly or is the nose dive causing the nose to make contact? Post them.

Have you contacted the author for help?

Gear will not break if the parameters in the contact point info are not exceeded. The crash may be caused by a faulty positioned contact point or by poor definition of the oleo compression parameters allowing the gear to sink through the surface thus allowing a crash point contact.

Better information yields better answers. Is it landing technique or the model data? Only you can help us determine that.

If you want us to work toward a solution for you, then you must do your homework to provide the parameters around the issue.

peter12213
May 6th, 2009, 14:19
Its actually the roland laborie crusader, and super etendard that i'm having the trouble with in acceleration, my flying i.e decent rate speed are fine its litterally something wrong with that jet! here are the contact points
with the mods to try and fix it which don't work!

Crusader.....

[contact_points]
static_pitch = 1
static_cg_height = 5.8
tailwheel_lock = 0
gear_system_type = 1
max_number_of_points = 14
point.0 = 1, 8.64, 0, -6.95, 3700, 0, 0.8, 34, 0.4, 3.0, 0.5, 5, 5, 0, 200, 300
point.1 = 1, -9.65, -4.5, -6.85, 4500, 1, 1.2, 0, 1, 2.5, 0.5, 7.9, 7, 2, 200, 300
point.2 = 1, -9.65, 4.5, -6.85, 4500, 2, 1.2, 0, 1, 2.5, 0.5, 8.1, 8.1, 3, 200, 300
point.3 = 2, -14.17, -17.9057, -1.0579, 787.4, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0
point.4 = 2, -14.17, 18.0173, -1.1334, 787.4, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0
point.5 = 2, -30.1246, 0, -3.7877, 1574.8, 0, 0, 0, 0, 0, 0, 0, 0, 9, 0, 0
point.6 = 2, 22.7403, 0, 0.5672, 787.4, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0
point.7 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.8 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.9 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.10 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.11 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.12 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.13 = 5, -30.90, -5.250, -7.300, 1600, 0, 0.00, 50.0, 0.0, 0.0, 1.00, 1.0, 1.2, 0, 0.0, 0.0

soon as i land the nose gear is fine, soon as i take the wire the nose hits the deck and thats the end of me, when i try with no hook .no problem..strange?

its the same for the super etendard when trying to launch from a catapult it nose oleo gives way and the nose smacks into the deck!!
I'm really frustrated as i'm in the process of modifying the super etendard for acceleration and any info from its author is not forthcoming!! I'm sure this is a [takeoff assistance] problem though!
I am however pretty sure on the crusader that the crashes are caused by poor definition of the oleo compression parameters .. how do I change those though?

Milton Shupe
May 6th, 2009, 16:02
Several things here to consider:

1. Contact point.0=1 shows nose parameters. The suspension is very stiff at .3 static compression, 3.0 max-static ratio, and damping at .5 is probably a little soft and bouncy and allows squishiness and ease of sinking in the surface.

Before changing this, understand that 3.0 X .3' = .9' or total suspension animation. If this agrees with the model's animation (i.e. the nose wheel can in fact move up/down 10.8"), then I would try changing those numbers as follows:

3.0 X .4' = 1' Current
2.0 X .6 = 1' First test
1.5 X .667 = 1' Second test

Change the Damping from .5 to .9 for these tests.

Example for first test:
point.0 = 1, 8.64, 0, -6.95, 3700, 0, 0.8, 34, 0.6, 2.0, 0.9, 5, 5, 0, 200, 300

Example for second test:
point.0 = 1, 8.64, 0, -6.95, 3700, 0, 0.8, 34, 0.667, 1.5, 0.9, 5, 5, 0, 200, 300

Secondly, crash point.6 shows a point of contact 22.704' forward whereas the nose wheel is at 8' forward. If you are getting a lot of nose dove, that crash point will ... well, crash you. Verify that is correct by putting those coordinates in a light statement. If it is correct, then getting the dive is is essential to success.

Thirdly, if this helps but is not totally successful, can you verify CoG is at 25% MAC? If it is less than 25%, then you are nose heavy and this exacerbates the problem. You will need to move the CoG rearward to 25-27%.

Last, I am not familiar with how the tailhook works but if contact point.13=5 is it, then I am curious as to why the location seems off center by -5.250'. Does it have twin tails or is the tailhook off center for real?
Also, should the tail hook location be denoted at its attach point (swivel) or at the hook-when-down point (capture end). It shows it -7.3' which is actually lower than the gear. Maybe try raising that to -6.85, same as the main gear.

peter12213
May 6th, 2009, 16:15
No my friend i didn't notice that about the tail hook! It is dead centre of the rear fuselage so i have no idea why they'd put it off centre but it doesn't really seem to be a problem tbh. I shall try what you have said and get back to you tomorrow as its 1.20am now..but you are right the landing gear is very soft and squidgy almost! The aircraft I'm working on is this one http://arnaud.mathis.free.fr/FSX%20Crusader/
The F8E FN Crusader of the French Navy, Its freeware, but, at payware quality, it really is a good jet and I reccomend it for carrier ops, well, after we're finished with it lol !!!

BTW...My CoG is fine I think, speed is between 110 and 114 for landing, litterally on the verge! this is one heavy beast but great to fly!!!

Thank you very much for helping me out your are a gentleman and a friend!

Milton Shupe
May 6th, 2009, 16:25
For clarification, the nose suspension is very stiff while the damping is "bouncy". However, for nose gear, a higher value in the damping position usually yields less tendency to push through the surface. And, I usually like to have lot sof suspension available for nose gears like this, then put a lot of that movement in the static compression with a ratio around 2.0. This is a very forgiving suspension when done correctly.

Thank you Peter.

peter12213
May 6th, 2009, 18:44
My friend I have tested and managed to fix the nose gear problem thanks to god and you lol but it has left me with my two main wheels looking like there off the ground.. can you help bring them down and help with that tail hook you were right it does pull to the left, and needs to be centered!!!

Here are the new contact points my friend...

point.0 = 1, 8.64, 0, -6.95, 2500, 0, 0.7, 35.0, 0.125, 7.0, 0.850, 5.0, 7.0, 0.0, 180.0, 230 <<--Nose oleo is fixed and is great!!
point.1 = 1, -9.65, -4.5, -6.85, 3500, 1.0, 1.1, 0.0, 0.450, 2.5, 0.8, 5.0, 7.0, 2, 180.0, 230 <<--Wheel off ground (how do I lower it, which numbers do that?)
point.2 = 1, -9.65, 4.5, -6.85, 3500, 2.0, 1.1, 0.0, 0.450, 2.5, 0.8, 5.0, 7.0, 3, 180.0, 230 <<--Wheel off ground
point.3 = 2, -14.17, -17.9057, -1.0579, 787.4, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0
point.4 = 2, -14.17, 18.0173, -1.1334, 787.4, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0
point.5 = 2, -30.1246, 0, -3.7877, 1574.8, 0, 0, 0, 0, 0, 0, 0, 0, 9, 0, 0
point.6 = 2, 22.7403, 0, 0.5672, 787.4, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0
point.7 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.8 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.9 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.10 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.11 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.12 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.13 = 5, -30.90, -5.250, -7.300, 1600, 0, 0.00, 50.0, 0.0, 0.0, 1.00, 1.0, 1.2, 0, 0.0, 0.0 <<-- Hook problem pulls to the left on landing!!

Slowly but surely I will get there!!! Thanks Milton!

Rich
May 6th, 2009, 18:58
Hi both, contact point 13 is a water rudder so not sure why it is there, tailhook and launch bar should have seperate sections in aircraft.cfg they are not part of contact points, re tailhook most have a cable force adjust figure of 1 try changing the 1 to 3.5 for a shorter stopping distance, I find with a setting of 1 with a heavy aircraft that I have almost run out of deck before I stop.

What have you got for Tailhook and launch assistance ?

Milton the tailhook should be the attach point on the aircraft, I use the light method to get the position on the visual model then use that for the tailhook entry position then adjust the tailhook length to get the catch point

"Also, should the tail hook location be denoted at its attach point (swivel) or at the hook-when-down point (capture end). It shows it -7.3' which is actually lower than the gear. Maybe try raising that to -6.85, same as the main gear."


Contact Point Parameter (and example) Element Description
1 (1) Class Integer defining the type of contact point: 0 = None, 1 = Wheel, 2 = Scrape, 3 = Skid, 4 = Float, 5 = Water Rudder

Milton Shupe
May 6th, 2009, 20:18
Ah, thanks Rich. That is helpful, and I forgot about the separate Tailhook section as I have never used that.

Milton Shupe
May 6th, 2009, 20:29
My friend I have tested and managed to fix the nose gear problem thanks to god and you lol but it has left me with my two main wheels looking like there off the ground.. can you help bring them down and help with that tail hook you were right it does pull to the left, and needs to be centered!!!

Here are the new contact points my friend...

point.0 = 1, 8.64, 0, -6.95, 2500, 0, 0.7, 35.0, 0.125, 7.0, 0.850, 5.0, 7.0, 0.0, 180.0, 230 <<--Nose oleo is fixed and is great!!
point.1 = 1, -9.65, -4.5, -6.85, 3500, 1.0, 1.1, 0.0, 0.450, 2.5, 0.8, 5.0, 7.0, 2, 180.0, 230 <<--Wheel off ground (how do I lower it, which numbers do that?)
point.2 = 1, -9.65, 4.5, -6.85, 3500, 2.0, 1.1, 0.0, 0.450, 2.5, 0.8, 5.0, 7.0, 3, 180.0, 230 <<--Wheel off ground
point.3 = 2, -14.17, -17.9057, -1.0579, 787.4, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0
point.4 = 2, -14.17, 18.0173, -1.1334, 787.4, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0
point.5 = 2, -30.1246, 0, -3.7877, 1574.8, 0, 0, 0, 0, 0, 0, 0, 0, 9, 0, 0
point.6 = 2, 22.7403, 0, 0.5672, 787.4, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0
point.7 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.8 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.9 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.10 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.11 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.12 = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
point.13 = 5, -30.90, -5.250, -7.300, 1600, 0, 0.00, 50.0, 0.0, 0.0, 1.00, 1.0, 1.2, 0, 0.0, 0.0 <<-- Hook problem pulls to the left on landing!!

Slowly but surely I will get there!!! Thanks Milton!

First, add a tailhook section to your aircraft IF it does not already have one (It should look something like this):

[TailHook]
tailhook_length = 8.0
tailhook_position = -30.90, 0, -1
cable_force_adjust = 2

I assume the following is for Launch assistance (not in my SDK for FS9):

[LSO]
LSOAdjustSpeed=0.7

Wheels off the ground: Adjust the vertical positions of the main and nose gear as necessary. The forth set are the numbers to adjust(class, fore/aft, left/right, up/down):

point.0 = 1, 8.64, 0, -6.95, 2500, 0, 0.7, 35.0, 0.125, 7.0, 0.850, 5.0, 7.0, 0.0, 180.0, 230 <<--Nose oleo is fixed and is great!!
point.1 = 1, -9.65, -4.5, -6.85, 3500, 1.0, 1.1, 0.0, 0.450, 2.5, 0.8, 5.0, 7.0, 2, 180.0, 230 <<--Wheel off ground (how do I lower it, which numbers do that?)
point.2 = 1, -9.65, 4.5, -6.85, 3500, 2.0, 1.1, 0.0, 0.450, 2.5, 0.8, 5.0, 7.0, 3, 180.0, 230 <<--Wheel off ground

The numbers in RED give the distance to the ground (relative to the aircraft reference). Decrease the number to lower the aircraft. (Anytime you adjust suspension movement, that lifts or lowers the tires. You must always adjust distance to ground after a suspension adjustment).

Btw, if you do not have the SDK (System Development Kit), you should get it. It explains all these parameters.

Last thing, delete contact point.13 water rudder. :)

cheezyflier
May 6th, 2009, 20:40
are you talking about the F-18? if i remember correctly, they reccomended a higher approach speed in the carrier landing tutorial than the one you are using.

Rich
May 6th, 2009, 20:43
I have spent a lot of time working on gears and hooks recently both on taildraggers and trikes to get the stopping distance right and to stop the noseover on taildraggers, got the noseover cracked now, another problem was main gear bounce, often got one that would bounce over the wires without catching

peter12213
May 7th, 2009, 03:11
Thanbks guys i'm gunna get the SDK like, I do need it!!! Got it sorted now however and a beutiful crusader working brilliantly in fsx acceleration!!...the tail problem was not caused by me slipping just before landing on final approach and correction, it is infact a stability issue which is no big deal tbh!!

The next task I have isgetting my Dassault Super Etendard to launch off a carrier!! This has a similar problem of the nose oleo giving way soon as i trigger the catapult launch.. any idea for this one chaps? Here are her contact points there is no problems of landing her she takes the wire with ease its only on a cat launch that i get problems!!

Dassault Breguet Seper Etendard Modernise!

[contact_points]
point.0=1, -22.6, 0.00, -7.0, 2000.1, 0, 0.79, 46.8, 0.5, 2.2, 0.7, 5.0, 5.0, 0, 0.0, 0.0
point.1=1, -38.4, -5.3, -6.7, 2500.8, 1, 1.08, 0.0, 0.5, 2.0, 0.9, 5.0, 6.0, 2, 0.0, 0.0
point.2=1, -38.4, 5.3, -6.7, 2500.8, 2, 1.08, 0.0, 0.5, 2.0, 0.9, 5.0, 6.0, 3, 0.0, 0.0
point.3=2, -46.1, -15.7, -3.1, 987.4, 0, 0.0000, 0.0, 0.0000, 0.0, 0.0000, 0.0, 0.0, 5, 0.0, 0.0
point.4=2, -46.1, 15.7, -3.1, 987.4, 0, 0.0000, 0.0, 0.0000, 0.0, 0.0000, 0.0, 0.0, 6, 0.0, 0.0
point.5=2, -51.5, 0.00, -4.0, 987.4, 0, 0.0000, 0.0, 0.0000, 0.0, 0.0000, 0.0, 0.0, 9, 0.0, 0.0
point.6=2, -11.7, 0.00, -0.5, 987.4, 0, 0.0000, 0.0, 0.0000, 0.0, 0.0000, 0.0, 0.0, 4, 0.0, 0.0

any ideas as to why the nose olea is giving way under catapult launch from these figures?
-----Plus point 13 on the crusader was for the tailhook, it was to make it flex up and down on contact with the deck i think!

peter12213
May 7th, 2009, 03:18
are you talking about the F-18? if i remember correctly, they reccomended a higher approach speed in the carrier landing tutorial than the one you are using.

No not the F18 Hornet the F8E-FN crusader http://arnaud.mathis.free.fr/FSX%20Crusader/ (http://arnaud.mathis.free.fr/FSX%20Crusader/)
I wish it did handle like an F18 I certainly wouldn't have any problems!!!

peter12213
May 7th, 2009, 03:22
I have spent a lot of time working on gears and hooks recently both on taildraggers and trikes to get the stopping distance right and to stop the noseover on taildraggers, got the noseover cracked now, another problem was main gear bounce, often got one that would bounce over the wires without catching

How did ya stop the nose over on tail draggers plus Rich have you got a way of cat launching the wyvern or skyraider I would certainly be very interested???

SkippyBing
May 7th, 2009, 04:47
The Wyvern should cat launch in FSX without any problems, it did in testing anyway...

Rich
May 7th, 2009, 16:07
peter12213, The Wyvern cat launches ok with no problems even though it is a tail dragger and I have adapted a number of other taildraggers using the same sort of setup copy paste this line to the Lights section of the Wyvern aircraft.cfg make sure it is the last entry last entry giving a total of 4 get on the deck of your carrier switch on the lights and you should have a green light on the deck under the nose this is the cat hookup point in the case of the Ark get that light on the cat shuttle do the shift + I bit and a wire should appear connecting that wire to points under the wings and the blast shields will come up, this is on Ark Royal currently the only carrier I use beside the WIP HMS Victorious.

Skyraider I do not have.

The nose dip cure I want to get to Skippy first for approval

light.4 = 3, 10.423, 0.0, -7.42, fx_navgre

Rich
May 7th, 2009, 16:35
Milton, the LSO thing is a leftover from CFS2 and does nothing anywhere else as far as I can see and can be deleted I do as a matter of course it was the old Landing Signals Officer or batsman that is on the rear deck in CFS2 giving visual instructions to a pilot on approach so no use in FSX.

As a matter of interest the default F18 has no entries in it's aircraft.cfg for tailhook or launch assist they are written into the model and are not needed.

I assume the following is for Launch assistance (not in my SDK for FS9):

[LSO]
LSOAdjustSpeed=0.7

Rich
May 7th, 2009, 17:34
peter12213 can you post the launch assist entries for both your problem planes there may be something there that is causing nosegear problems these settings will affect launch atitude dragging the nose down or the tail if not correctly set.

That site for the Crusader is all in French so I am stuck there, plus no sign of a Crusader.

peter12213
May 9th, 2009, 19:39
peter12213 can you post the launch assist entries for both your problem planes there may be something there that is causing nosegear problems these settings will affect launch atitude dragging the nose down or the tail if not correctly set.

That site for the Crusader is all in French so I am stuck there, plus no sign of a Crusader.

I can give you my corrected points for the crusader and direct you to the site i got it from !! she is now totally fsx acceleration copatable thanks to all our hard work!!

delta_lima
August 5th, 2010, 01:16
Hello Pete,

Wondering if you were able to get the Crusader launch bar sorted out.

Wondering if there is a listing somewhere of launch bar additions to various FSX naval aircraft? That would certainly save a lot of time. First I'd like to start with the Crusader, but up next I'd like to tackle the Alfa Ciel Bleu Bearcat and Corsair for FSX.

Many thanks!

dl