Simviation Forums

Greetings all,

First time post for me, a definite ignoramous when it comes to tweeking programs and computers, however I do have a bit of real time flight experience and just a few months ago discovered the wonderful world of FS2004 add-ons.

As to the subj of this post, I downloaded a particular WWII British pedigree special ops aircraft which flies well and appears to be realistic as to handling.

Problem is it shakes (just the aircraft) as soon as it gets the promt to "fly now".  The scenery does not shake.  Imagine a prop tip missing or a terrified male goat passenger running rampant in the cockpit.  Shaking will subside at lift-off but will return when some altitude is acquired and turns are started.

The zip file was without sound and a text file  suggested appropriate files to use.  I tried 3 different sounds and no change.  I also flew it with no sound file.  Again, no change.  Tried different locations and dropped all weather effects.  No difference.

I am baffled.  Perhaps something was scrambled in the download process?  At any rate I really like the aircraft and this is in no way a negative criticism of the work done by the creator.  I'd just like to fly it without wearing a dental mouth guard.  Any hints as to fixes would be appreciated.

Cheers to all,

Gounded3946

What file did you download.  This is important to know.  After all, how can we tell if it was Sidney Cotton's Lockheed, a Lysander, or even a Whitley?

Obviously, what plane doesn't really matter as much as the file you downloaded.

Of course, if others have downloaded the file and don't have the "shakes", it could be something related to an add-on scenery, or even the particular airfield from where you're taking off.  (Note:  I had a model that sat perfectly on most of the default fields I'd tested, EXCEPT Pyongyang - where it was supposed to have sat perfectly!)

The downloaded file shows up as spoplyv3.zip which is the Lysander currently on page 14, Vintage FS2004.

Incidentally, when some altitude is reached, say 2500 AGL and engine is throttled back to idle and wings leveled the shaking will cease/lessen but not always.

Spot plane's view before take off is stable and the Lysander just sits there and bucks.  Take off is bumpy as if the tires were square.  I get the impression that the engine is going to rip its way out of the mounts and almost expect to see it laying on the runway at any second.

Again, I really like this aircraft... side slips will lose altitude rapidly although the speed doesn't bleed off very quickly.  This I would expect from such a profile (no slab sides here).  Landings are impressive in that it can be dropped in from a considerable height from just above stall and there is little tendency to ground loop.
Definitely a short rough field airplane.  It flies like it looks.  All business.

Thanks much for the reply!

Gounded3946  

Hello Grounded3946,

Welcome to SimViation,

I tried it and indeed it's a very shaky ride. Maybe this is because the Lysander was originaly designed for CFS2? As long as it's flying, it flies great.

Crash

This is a dead easy one

In your aircraft.cfg file, first change the top section so it appears in your Select Aircraft List and you get an ATC type

[fltsim.0]
title=Westland_Lysanderv3
sim=Westland_Lysanderv3
model=
panel=
sound=
texture=
kb_checklists=
kb_reference=
atc_id=44375
atc_airline=AIRFORCE
atc_flight_number=
ui_manufacturer=Westland Aircraft
ui_type=Lysander
ui_variation=WWII Special Ops
description=Westland Lysander

[general]
atc_type=Westland
atc_model=Lysander
performance=Weight: 4,300 \/ 6,700 lbs\nEngine: Bristol Mercury XX\n9-cyl. air-cooled radial, 820 hp\nMax speed: 220 mph @ 5,000 ft\nCeiling: 20,000 ft\nRange: 400 mi at 150 mph or\nwith drop tanks, 900 miles\n\n\n


Then the bit that matters, change your MOI section as follows

[WEIGHT_AND_BALANCE]
empty_weight=4300                        // (pounds)

reference_datum_position=0.0, 0, 0      // (feet) distance from FlightSim Reference position: (1/4 chord, centerline, waterline)
empty_weight_CG_position=0.0, 0, 0       // (feet) longitudinal, lateral, vertical distance from specified datum

max_number_of_stations=50

station_load.0=170,  -1.0, 0.0, 1.0            //Pilot           Weight (lbs), longitudinal, lateral, vertical positions from datum (feet)

;Moments of Inertia
empty_weight_pitch_MOI=33673
empty_weight_roll_MOI=27888
empty_weight_yaw_MOI=18226
empty_weight_coupled_MOI=0.00000
max_gross_weight=6705


You will now have a lovely little aircraft that flies just as I think it should, nice and stable but make sure you trim it right in all stages of the flight. That's the way props were then - proper hands-on, especially in the approach. You'll get a lovely short landing with full flaps at around 70 kts or so. I'm reluctant to increase the flap drag to make it slow down quicker or the flap lift to make it fly even slower because that would take too much pilot skill out of it.

Speaking of a whole lotta shakin...did you kn ow that Jerry Lee Lewis married his 13 year old cousin! :-/

A.

Speaking of a whole lotta shakin...did you kn ow that Jerry Lee Lewis married his 13 year old cousin! :-/

A.

Did you know that 90% of the population of Tennessee is married to thier 13 year old cousin?

Gents,

Thank you all for the comments and instructions.  This is outstanding.  I will apply the fixes as soon as I can which will unfortunately be tommorrow earliest.

We are preparing for an infestation (er, ah... I mean visitation) of in-laws to arrive in a few hours to help celebrate my wife's 50th birthday.

I am supposed to be outside as I post this mowing the lawn.... not playing with airplanes etc.

Cheers,

Grounded3946

".... goodness, gracious, Great Balls o' Fire"

Rollerball etc,

A thousand thank you's.... I changed the numbers in the MOI section and now the aircraft has no more shakes.  

Flies just fine and you are right about the Lysander being trim sensitive.  Retract the flaps and it wants to dive right now.  A delight to fly but requires alertness.  It is real easy to get an accelerated stall if you are slow and you bank it steeply and pull back too briskly.

I'll get around to changing the top section of the aircraft.cfg file some other time in the next day or so.  Going to the "Unspecified" area to pull up the Lysander is fine for now.  There are in-laws downstairs as I post, they can wait.  (Hee, hee)

Thanks Again!

Gounded3946