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Spirit of St Louis

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Few fly this aircraft because it is so unstable.Unfortunate because it is an historic aircraft.Here are some tips on making Spirit usable.Set FS to Easy in Settings; uncheck auto rudder.It is grossly underpowered resulting in long clumsy TO's.L states in WE (my 1929 copy) that Spirit "passed its tests easily and took off with 300 gallons of fuel in twenty seconds or 1023 feet, and made a maximum speed of 126 miles per hour."Create a flight test flight w/300 gal. to check the as issued performance. 20 seconds plus 2 sec throttle advance to 80 mph is my reference.Initial adjustments:Set [piston engine] power_scalar to 1.23 for a test series.Set [propeller] to the same value. Adjust both as needed.Set max_rpm_friction scalar to 1.3. To brake engine rpm.After TO settings are right, test speed to a nominal 126 mph full throttle. Use the digital display. Try to keep alt. within 50 ft of say, 1000 ft. REM to center the ball two clicks left trim. Use the Carpenters Level to keep wings level. Difficult but accurate.Set [flight tuning] parasite_drag scalar to 1.41 to control speed.Each cptr/card/display/flt control will differ so set to please.Next, adjust the Chord from 6.5 ft to 7 ft in [airplane_geometry].Don Hall, chief engineer Ryan, in naca-tn-257 says 7 ft.Find the report on the Lindbergh web site.Adjust the htail_pos_lon to -17.475 and vtail_pos_lon to -17.975 to pick up the change in quarter chord reference of the empennage.I've tested for a 13ft chord. A/C is a slug to 100 mph and oscillates in pitch. So the cfg file does affect aero.The 6 inch chord increase is a major aero change.Other: I set [flight tuning] elevator_trim_effectiveness to 1.2 for normal flight because the A/C pitch change is considerable at differing weight and a/s. Start the speed test w/o change in stock pitch TO trim till a/c accelerates to around 100 then nose down trim.L states he used reduced power trip SD to SL climbing to 4k. He climbed to 12k crossing the Rockies and climbed to 10k enroute Paris.I use 1.0 on the max_rpm_friction scalar vs 1.3 for climbs above 7k. Enroute Paris now at planned 2.5k.When satisfied with performance Easy settings, option is to make the a/c Realistic "Hard" to suit. It's an MS joke.

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I obtained Ev Cassagneres book Untold Story of Sprit of St Louis and Spirit and Creator by Nova Hall. Donald Hall was his father and Ryan engineer for Spirit.Both have pics of the aircraft under construction for reference of major components such as fuel tank locations.Cassagneres has excellent drawings showing stations by inches from STA 0. Drawings and pics are worth the $15. It doesn't have a scale so I made my own from stations that matched one inch on a protractor by 1/16 inch. Quarter Chord used in FS9 is 8.09 inches aft drawing STA 0. I converted all measurements to real inches and adjusted for Quarter Chord for the empennage and gas tank locations. Then to feet for Acft config. I adjusted rudder and elevator areas to match designer specs. I then readjusted engine power to L's specs for 300 gallon test and then parasite drag for speed.450 gal test is very stable on TO run and in level flight well behaved. At lower fuel weights it is mildy unstable laterally. Skids badly in turns - a common replica complaint. Spirit does not have rudder or aileron trim. Adjustments were ground made to the rear left strut and fixed portion of the rudder to L's satisfaction. Setting for one cruise speed. I can make the aircraft as unstable as I want in FS9. Landings are a problem initially because of restricted forward vis. Same for L. I use the periscope for lineup of the runway. Easier at night. Best to be a little high and idle keeping the runway in the periscope till overrun appears in side window. A/C are normally flown in balanced flight. Sprit is flown unbalanced using lots of rudder. L did it that way as shown in an approach to Croyden UK. Rt aileron is sticking up, slight left bank.Being held in a left skid using rt rudder. Since Spirit,at low fuel weights, has a very large wing surface and relatively powerful engine it can STOL to landing. Work the rudders and alilerons holding descent with power till relative motion stops. Piece of Cake

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