Springflyer project intended

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Tech Sergeant
Mar 2, 2005
Berlin (Kreuzberg)
Hi All!

I have been around on other pages, notably on Springsharp Springstyle, some interesting programs for armchair warship designers.

My question is, would it be possible to make a project (let´s call it Springflyer) similarely for aircrafts to get performence estimations? :?:
This is more intended for gamers for obvious reasons (name alone ressources) but it could be fun. I collected some aspects which should be included and leave them here for discussion to those more familar with the matter.

SPRING Flyer v.0
By ww2aircraft.net folks :D

Aircraft Specification Simulator
based upon
Spring Style
By Rick Robinson

Comments are encouraged on these changes and other
features of the program!


The program (is planed) to use a dialog to let you specify the basic
characteristics of the aircraft, and then modify and refine them in
order to get the balance of qualities you want. You may either
sim a new design or modify one that you (or someone) already

New designs:

In sequence, you are asked to enter:

-- Type and name of the proposed design

-- Year aircraft designed (*not* in use, nor date of design for the engine (subsequently asked below)): This determines
the basic technology level of the aircraft (possible dates for 1900-1950).

-- Dimensions (wings): Spanwidth, wingarea, airfoil thickness (Aspect ratio). You may then
specify material (wood, Dural, Steel) flaps size, leading edge slat size or slats. Finally the program
asks for
-- Block coefficient (wings): Fullness of the wing form (the program will tell you the typical ranges from straight
solid to sharp swept back laminar flow).

The program then computes the typical lift, drag, weight, structural strength and space of the wings dry, You may now put additional weight for
structural reinforcements of the wing according to the prupose needs (Fighter have more G-loadings and therefore need
reinforced wings).

You can accept the dimensions and weights for the wing, or revise them
till you get the desired weight. When you accept
the wing design, the program then asks for:

-- Dimensions (fuselage): length, beam, height. You may then specify material (Wood, Dural, Steel) and the cockpit size. Finally the program
asks for
-- Block coefficient (fuselage): Fullness of the hull form (the program will tell you the typical ranges from
solid to very fine forms of fuselages).

The program then computes the typical drag, weight, structural strength and space of the raw fuselage dry, You may now put additional weight for
structural reinforcements of the fuselage according to the prupose needs (bomber need a
reinforced fuselage to deal with bomb loads and additional related equipment).

-- controlls: Enter rudder size for horizontal vertical stabilizers. (the program will tell you the typical ranges for
effective rudder sizes)

You can accept the design figures for the airframe, or revise them
till you get the desired values. When you accept
the airframe design, the program then asks for:

-- gun Armament: Number and caliber of primary (fixed), secondary (fixed),
tertiary (flexible, defensive only), and 4th-battery (flexible, defensive, only) guns; number of tertiary and 4th battery
turrets (or open mounts, for planes before 1920),position of the primary and sec. guns (nose mounted, belly mounted
wing root mounted, mid wing mounted or outer wing mounted) and some
aspects of turret arrangement (belly, back, nose, rear and side mounts);
-- bomb armament: number weight of droppable bombload and aspects of their storage (fuselage stroed, under wing stored, under fuselage stored)

-- "Miscellaneous" weight: This is a catchall for weights
not specified in the program. Regular fittings like gunmounts
don't need to be entered, but you can use this to
provide for radar equipment, rescue equipment, cargo capacity for transports, armour etc.

Note: For any component you don't want, enter zero. The
program will move on to the next; for example, if you enter
zero tertiary guns, the program won't ask you their caliber.
You have to have at least one main-battery gun
(The program won't protect you, though, from "0-inch" guns.

-- Year of design for engine: This determines
the basic technology level of the power plant.

-- Engines: Number and type (radial, line, V-, early axial jet, early radial jet engine or rocket engine)of engines and their mountings
(nose, rear (implys pusher for props).
desired top speed at altitude or engine horsepower per unit. The program computes and reports the
corresponding value for horsepower, top speed, weight,space and coolant needs.
You are now asked to turbo- or supercharge the engine unit and to dimensionate and place the cooling unit/-s.
(You may trade some cooling effectivity for aerodynamic cleaning but this has detremental effects, also)

-- fuel: Enter a cruising speed and altitude,
or use a standard cruising speed to determine range (cruising speed at 15000ft. altitude).
The program computes this, and gives
you an option to change fuel tank volume for wings and fuselage as You desire (the program adjusts
the values for range automaticly). (Large cruising radius means more
weight space is given over to bunkerage, leaving less for
everything else).

You can accept the dimensions and weights for the powerplant, or revise them
till you get the desired performance. When you accept
the powerplant design, the program then asks for:

-- landing gear: With the datas for weight and equipment the program tell You the typical weight and space needs
for landing gear. You are asked to specify gear type (skid, fixed gear, retractable gear with main wheels retracted into
either fuselage or wings)

The program then computes the relative strength of the
airframe. If the hull is too weak, and subject to strain, you'll
get a warning; on the next pass you'll have to reduce speed
(i.e., a smaller propulsion plant) or sacrifice guns or misc. weights
to beef up the hull structure. If you get a composite strength
above 1.00, you can add speed, guns, or armor -- subject to
other constraints.

For normal planes, composite strength of 1.00 is the
target to aim for, but this may be relaxed for some light,
fast recon types.

Note: "excess" hull strength - greater than 1.00 -
will produce a plane that is undergunned (or otherwise
underperforms) in proportion to its size. This should
generally be avoided except for high altitude planes, for which low wingload
corresponds to good altitude behavior.

You'll also get advisories on some operational
characteristics, such as manaeuverabiity and crew

The program also computes the plane´s relative margin of
stability and its non combat abilities (time to altitude, max G-forces to sustain,gunplatform achreckteristics,
critical Mach speed, effective turning radius and speed, take off distance, landing (stall) speed, Crew roomyty).
You can then select:

-- Relative steadiness as a gun platform: This is a
trade-off via trim; the greater the steadiness, the lower the margin
of maneuverability and the less damage the plane can

The program then re-computes the stability, based on your
chosen steadiness, and also adjusts maneuverability for
plnae with low steadiness and therfore a quick roll rate.
Finally, the program gives estimates of how much
(penetrating) gunfire (0.50cal and 20mm) the plane will survive (These do not count "critical hits"
like magazine, pilot or fuel tank hits!).

Now you get an option of viewing a summary report of the
design and of saving a more complete report to a file.
The file report starts with a "Del's" style summary of the aircraft, followed by more detailed
program output.

Note: Spring Flyer is a DOS program, and can only read DOS
style file names, limited to eight letters or numbers, followed
optionally by a period and a three-character extension, e.g.,
NAME.TXT or NAME.DOC. Your design files should follow
this format, so that the program can find and read them for

You can then exit the program, start another design,
or go back and refine the present design.

I expect a timeframe of ~two years for such a project and in case there are enough people to feel encouraged for the programming works.
Biggest work is to get all datas necessary and sustainable interest in the project. I would be glad to hear Your ideas whether or not You feel this is a bridge to far or possible. And anything else, of course.
Hope You will throw some minds into this. I am leaving this forum for field excavation in Cyprus till september.
No, there is no such program avaiable now. In case I find enough time, there will be one coming. But be sure, it will be a procedural metric version as I stick to metrics:oops: .
For those who want to be armchair designers I suggest
the planebuilder excel worksheet from Rick Robinson. Not really user friendly but worthy.

The Observatory

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