Version 2.3 (1 Nov 2010)

The Roncz Spreadsheets (EAA, 1989-1991)With notes, formatting and some additions by Duncan Meyer, Brisbane, AUThese are the original 1990 spreadsheets written by John Roncz which I have formatted for ease of use.Please read them in conjunction with his excellent series of articles.

1 How this workbook is organised:I have taken the eight separate Roncz spreadsheets and placed them in this self-contained multi-page workbook, so they are now all in one conveninet location.I have renamed the individual sheets to indicate which EAA article it is linked toColor codes used: Personal data. Either from drawings, measurements or wish-lists

"Static" data - drawn from expereince, rules-of-thumb, history etc.Calculated cells - best not to fiddle with these...

2 Summary of all sheets in this workbook

Roncz8-Jan913 How to use these spreadsheets

Read the first Roncz article (Nov '89), then examine the Roncz1-Nov89 spreadsheetEnter your data into the GREEN cellsNote the results as they appear in the RED cells - you will need these in later sheetsContinue to the next Roncz article (Jan '90), and refer to the JAN sheet (...etc)When you arrive at the final sheet (Roncz7-MAIN-Aug) you should have all the data you need.

4 I have embedded quite a few Notes and Tips for using these sheets. Hold your cursor over these bright yellow "Readme"s . Like the example below5 Readme6 I have added some behind-the-scenes calculations. These are completely optional, but they do make life a bit easier. They are clearly identified.

.NB Read Intro2 for a step-by-step guide to using the Roncz spreaddsheets

Roncz1-Nov89: A convenient stand-alone spreadsheet, where you can enter different speeds, altitudes etc, and get various dependent answersRoncz2-Jan: Sizing wings, using claps, Lift, Flat plate areaRoncz3-April: Referenced in the April PDF "Tail Incidence part 3"Roncz4-CG-May: This is where you enter all your component weights and moment arms PDF="Forward Sweep and the Great Crisis"Roncz6-June: A stand-alone worksheetRoncz7-MAIN-Aug: The main spreadsheet

duncan.rtfm@gmail.com

These are the original 1990 spreadsheets written by John Roncz which I have formatted for ease of use.Please read them in conjunction with his excellent series of articles.

I have taken the eight separate Roncz spreadsheets and placed them in this self-contained multi-page workbook, so they are now all in one conveninet location.

Personal data. Either from drawings, measurements or wish-lists"Static" data - drawn from expereince, rules-of-thumb, history etc.

I have embedded quite a few Notes and Tips for using these sheets. Hold your cursor over these bright yellow "Readme"s . Like the example below

I have added some behind-the-scenes calculations. These are completely optional, but they do make life a bit easier. They are clearly identified.

: A convenient stand-alone spreadsheet, where you can enter different speeds, altitudes etc, and get various dependent answers

: This is where you enter all your component weights and moment arms PDF="Forward Sweep and the Great Crisis"

Version 2.3 (1 Nov 2010)

A step-by-step guide to using the Roncz spreadsheets

WING INPUTSStep 1

Step 2You need to make some basic choices.

Step 3Probably one of the more critical choices you need to make is WHERE to place the wing. Too far forward will affect how your plane flies (or doesn't fly)

Step 4

Scenario: You want to design your own plane, but don't know where to start

Solution: The following notes refer to the new sheet, called "Basic Inputs" which I have created in order to bring together all the inputs required to design your airplane. There will be some back-and-forth between the other sheets, but essentially if you can provide all the inputs in the "Basic Inputs" sheet, you will be well on your way to designing your airplane. Follow these easy steps to completing the basic inputs required - you can find these on the sheet called "Basic Inputs"

Draw your plane as accurately as you can. Don't have high-end CAD software? Download a (free) copy of the Google "Sketchup" software from google.com CAD doesn't get easier (or cheaper) than this. Spend the time (maybe an hour or so) to learn how to use Sketchup. This is very much "entry level" CAD software, but it DOES allow you to draw accurate 2-D drawings with very little effort.

Choice 1: Stall speed (Vs). The stall speed is dependent on a number of things - eg: Wing area, lifting capacity of the wing (CL), and the weight of the aircraft. It's all a big trade-off. For example, the bigger the wing, the slower the stall, but your aircraft will have more drag, so it will fly more slowly. The inputs in the "Basic Inputs" worksheet will show you these trade-offs, and help you decide. Once you've chosen your stall speed, and you've estimated the weight of your airplane (flying weight that is - including you, fuel baggage etc - the Max All-up Weight), all you need to do is choose an airfoil and read off the maximum lift co-efficient (with flaps) at zero feet - you're on the ground, after all...

Choice 2: Wing Aspect Ratio (AR) The bigger the AR, the more efficiently your plane will fly. But as AR increases (for a given Sw) the shorter the chord (the wing will be longer and skinnier). And this means that the wing will also be thinner. And thinner means less height for your spar. And as spars become less deep, they lose strength very quickly, and you need to build them stronger (ie heavier). So now you have a trade-off between efficient wing and heavy wing. Rule of thumb: aim for an AR of somewhere between 6 and 9.Choice3: Airfoil thickness percentage (t/c). Usually about 15% but can be as low as 12% and as high as 18%

Together these inputs will feed into the "feedback" calculations in column E. Don't worry if these numbers don't make sense at the moment - they will. But you will need to make quite a few more entries before it all begins to come together. Change the stall speed and see how this affects the wing area. Change the MAUW and see what difference that makes. See how these changes affect the max speed, glide, slimb rates etc. Play with this till you're reasonably happy with your compromises. You can always change this later, so this isb't critical at this stage.

On the "Basic Inputs" sheet, you will see a yellow highlighted cell for this input. It is measured in INCHES rearward from your DATUM. I have used the prop bulkhead as my datum, but you can choose any datum you wish. Some people use the tip of the spinner - but then you can't change your spinner without having to recalculate your centre of gravity. Some people use the firewall. It's your choice.

To begin with, you will need to enter a number in this cell based on the eye-ball technique. Select a wing position which looks right - you will DEFINITELY be changing this as you progress, so it doesn't really matter what you choose now. But it helps to be in the ballpark...

Step 5

CENTRE OF GRAVITY inputsStep 6

PROPELLER inputsStep 7If you know what prop you're going to use, take your inputs directly from your prop. You will need to work out the cruise RPM and airspeeds

ENGINE inputsStep 8

Enter your engine HP, and the BSFC. Generally speaking a BSFC of about .45 is a good estimate for a modern engine. But if you have the exact numbers, enter them here

TAIL inputsStep 9

Airplane angle of attack) should be zero or nearly so. It makes sense (to me at least) to want your plane to fly level, not nose down or nose up. Hence I suggest zero is a good number…)

OTHER INPUTS

The Roncz4-CG-May sheet

The Roncz2-Jan sheet

The Rancz3-April sheet

Enter the tail moment arm. This should also be taken from your drawings. You measure the tail moment arm from wing MAC/4 to tail MAC/4 In English this means (1) calculate the wing Mean Aerodynamic Chord (MAC). On a rectangular, non-swept wing it is easy. Your MAC is your chord. For a swept wing or a tapered wing, things get a little more complex, but Roncz has provided the calculations to do this for you. You can find it on the Roncz3-April sheet (cell E19). (2) Now that you have your MAC, measure back 25% from the leading edge. ie if your chord is 48in, a quarter of 48 is 12, so mark 12 inches back from the wing leading edge. (3) Now do the same for the horisontal stabiliser.. (4) Finally, measure the distance between the wing mark and the h-stab mark. This is your tail moment arm.

The following three inputs (Design lift coefficient, Wing Drag Coefficient and CM of MAC Airfoil at the Design CL) need to be entered using data from the published data of your chosen airfoil. Which airfoil to use? This is very much a personal choice - but you really can't go wrong with using one of the Riblett airfoils. You will need to buy his little booklet (the only source of published data on his airfoils I know of) - but the booklet is cheap, and readily available from Aircraft Spruce.

Jump to the Roncz4-CG-May spreadsheet, and fill in the Fuselage Station (FS) and Waterline (WL) as well as the weights for all the listed items. Remember, the FS numbers are in INCHES back (ie tailwards) from your chosen datum. The WL measurements are from an arbitrary line also (most people use a line drawn horisontally through the propshaft. When you have filled in all FS and WL measurements, and estimated as best you can each of the weights, you will end up with two significant numbers: the CG of your aircraft as measured horisontally (B25), and vertically (C25) These numbers will automatically be copied back to your "Basic Inputs" sheet into cells E17 and E18

The first input (Horizontal Tail dCL/dAlpha) is not something you can guess. In fact, notice that it is in a RED cell - meaning that it is calculated elsewhere, and copied into this cell. Actually, now would be a good time to jump to another worksheet, and fill in the inputs there. Go to the Roncz3-April sheet, and copy into the green cells, the values you have decided on already. Notice the RED cells in row E These will be used again elsewhere. Now return to the Basic Inputs worksheet

The following four inputs (lines 36 to 39) can all be understood by reference to the original Roncz articles, which are referenced in the notes attached to each of the cells. Go off and read the articles, come back and fill in the four cells with sensible data.

Some of the Roncz spreadsheets are little more than stand-alone calculators to work out various things. However, the Roncz2-Jan sheet, Roncz3-April sheet and the Roncz4-CG-May sheet are critical. Take values you have already selected in your Basic Inputs sheet where neccessary.

This sheet allows you to calculate the CG as well as the weight of your airplane. Don't worry too much about being 100% accurate with the weights and positioning of each item. Give it your best shot, however, to ensure as accurate a result as possible. Don't worry too much about the weight of the cowl. I didn't. I simply included it in the weight of the fuselage shell itself.

This is a very important, and most interesting sheet. You should have most of the GREEN cell inputs already - except for those in cells D56 to D61 (the wetted areas). This in turn leads on to being able to calculate your equivalent Flat Plate Area, which has a number of important effects on how fast your plane will fly. I have included quite extensive notes at the bottom of that sheet to walk you through the process.

Again, easy inputs (you should have all of them worked out by now) leading to some critical calculated cells culminating in the recommended vertical and horisontal tail sizes. Bigger than this is OK, but not smaller.

FINALLY

First, there are some inputs at the top of the sheet to calculate the Aerodynamic Center Along the MAC.

Second, you will need to enter the inputs to calculate the Pitching Moments due to the Fuselage/Wing Combination. Read the "Readme" note for directions to the Roncz article dealing with these inputs.

Good luckDuncan Meyerduncan.rtfm@gmail.com

You are now in a position to go to the main sheet - the Roncz7-MAIN-Aug sheet.

And that's it. Your goal is to see sensible numbers in the "Power on Neutral Point" section - rows 142 to 154. I have highlighted the critical lines in red. Bottom line, your Static Margin needs to be between about 5% and 20%. 5% will result in a very responsive, sporty plane. 20% will result in a stable, no-surprises aircraft. Anything less than 5% is probably going to be too sensitive, and towards the 20% limit, soo docile.

If your Static Margin falls outside these broad limits, you're in trouble, and it's back to the drawing board. So retun to the Basic Inputs sheet, and start fiddling. Notice that I have placed a number of calculated fields in col E. Of particular interest is the Static Margin and the Dynamic Stability Ratio. Fiddle with your aspect ratio, and the HS positioning of your wing. Both will alter these two numbers. Remember, if your Static Margin is too low, you won't be able to fly the plane. Too high is also bad. And then aim to get your stability ratio between generally acceptable limits as indicated on the sheet.

.

A step-by-step guide to using the Roncz spreadsheetsScenario: You want to design your own plane, but don't know where to start

Solution: Follow these easy steps…

Step 1

Draw your plane as accurately as you can. Don't have high-end CAD software? Download a (free) copy of the Google "Sketchup" software from google.com CAD doesn't get easier (or cheaper) than this. Spend th

A step-by-step guide to using the Roncz spreadsheetsScenario: You want to design your own plane, but don't know where to start

Solution: Follow these easy steps…

Draw your plane as accurately as you can. Don't have high-end CAD software? Download a (free) copy of the Google "Sketchup" software from google.com CAD doesn't get easier (or cheaper) than this. Spend th

Draw your plane as accurately as you can. Don't have high-end CAD software? Download a (free) copy of the Google "Sketchup" software from google.com CAD doesn't get easier (or cheaper) than this. Spend th

Aircraft Data Input sheetThis is your main sheet for inputting data, which will act as inputs on other sheetsInput all values in the green cellsOn the right (column E) are some calculated values, based on your inputs. Use these as a sanity check on the values you input

WINGDesired stall speed (kts) 45.0

718.60 327Wing Aspect Ratio 8.5

Airfoil t/c 0.15Leading Edge of MAC is at FS (in) 43.00

Design lift coefficient 0.300Wing Drag Coefficient: 0.006

CM of MAC Airfoil at the Design CL: 0.012Dynamic Pressure at Design Point (Q) 99

CGWaterline of Aerodynamic Center (in): 0.00

Waterline of Thrust at FS of CG (in) 0.00

PROPPropeller RPM: 3200

Prop Diameter (in): 64Average Blade Width (in): 5Airplane Max Speed (kts): 212.48

Number of Blades: 2Distance from Prop to CG (in): 1

True Airspeed (mph): ?

ENGINEEngine choice AeroveeHorsepower: 100.00

BSFC 0.450

HORISONTAL TAILLeading edge of tail MAC is at 125.0 Readme

Tail MAC (in) 18.0 ReadmeVolume coefficient (ThC) 0.65 .45 to .65

Power Off Dynamic Pressure Ratio at Tail: 0.80 ReadmeTail Incidence Selected (deg) -1.30 Readme

Elevator Area/Tail Area (%) 100.00 ReadmeWing CL with Level Fuselage 0.30

Airplane Angle of Attack 0.00

VERTICAL TAILLever arm, inches 79.37Volume coefficient (TvC) 0.045 (Raymer: .035 to .065)

MAUW (from Roncz4)

On the right (column E) are some calculated values, based on your inputs. Use these as a sanity check on the values you input

Use these to see effects of the green inputs2.19 (Link to B85, B86, B87, B88 - depending on your flap type)

Wing area 47.96Wing span (ft) 20.19 Wing Loading 14.98

Chord (in) 28.50 Power loading 7.19Spar thickness (in) 4.28 rho at sea level 0.00237689

(Trade study) stability ratio - 2.5 to 3.5 2.78Distance from wing TE to AC of Tail: 58.00

Airplane Flate Plate Drag (sq. ft.): 0.93Wing Lift Curve Slope dCL/dAlpha: 0.09

Tail moment arm (in) 79.37FS of Center of Gravity (in): 45.65

Waterline of Center of Gravity (in): 0.90 Wing Loading: (kg/m^2 - lbs/ft^2)FS of Aerodynamic Center (in): 50.13Static Margin is (% of the MAC) 7.5%

Best L/D (kts) 86.38Best L/D 15.53

Min. Descent (kts) 65.62Descent (ft./min.) 494.66 kph mph

Max Speed (kts) 212.48 393.5172757 244.52029919Cruise speed (80% power) 169.99 314.81382056 195.61623935

Landing speed (kts) 58.50 51.78507525

(Span)Required H-stab Area:(ft^2) 12.07 8.0445780894Horizontal Tail dCL/dAlpha: 0.09 Readme Wing Loading: (kg/m^2 - lbs/ft^2)

FS of Tail AC (in) 129.50Required V-tail Area (ft^2) 11.20

Vertical Tail Size (ft^2) 6.59

(Raymer: .035 to .065)

MaxCL (with flaps) - (From Roncz2)

TRADE STUDIESRazorback Luciole SD-1 Corby StarletMetric Imperial Metric Imperial Metric Imperial Metric

Wing Span: (m/ft) 20.19 6.9 22.64 19.60Wing Area: (m^2/ft^2) 47.96 4.6 49.51 64.60

Aspect Ratio: 8.50 10.35 10.35Fuselage Length: (m/ft) 10.05 14.27

Stall (mph/kts) 45.00 34Cruise (mph/kts) 169.99 97

Empty Weight: (kg/lbs) 186.00 97 213Max Take Off Weight: (kg/lbs) 718.60 200 440 254 559

Wing Loading: (kg/m^2 - lbs/ft^2) 14.98 43.48 8.89 8.65Stability Ratio 2.78

HP 100 25 25 28990 627 627

Dry Weight (ex Exh): (kg/lbs) 154 23 50.6Engine bits (kg/lbs) 15.0 7 15.4

BK-1Metric Imperial

Wing Span: (m/ft) 19.40Wing Area: (m^2/ft^2)

Aspect Ratio:Fuselage Length: (m/ft) 15.40

Stall (mph/kts)Cruise (mph/kts) 130.00

Empty Weight: (kg/lbs) 430Max Take Off Weight: (kg/lbs) 800

Wing Loading: (kg/m^2 - lbs/ft^2) #DIV/0!

Two Cylinder, Four Stroke: 60

Dry Weight (ex Exh): (kg/lbs)Engine bits (kg/lbs)

Weights: 

Engine:      

Capacity: (CC)

Weights: 

Engine:      

Capacity: (CC)

Corby Starlet Aerochia LT-1 Hummel B612Imperial Metric Imperial Metric Imperial Metric Imperial

18.60 20.80 19.40 6.9 22.3068.50 6.8 70.70

6.0 6.014.90 15.30 15.40 4.8 15.50

35 40113 130 150

430 175 375800 300 662

0.00 #DIV/0! #DIV/0! 9.36

70 60 60 80

Aerochia Corby Starlet

B612

Wing Span: 19 feet 4 inchesLength 15 feet 4 inchesCockpit Width: 24 inchesCockpit Height: 40 inches (curved canopy)Leg Room: 50 inches (firewall to seat back bulkhead)Fuel Capacity: 15 gallonsEmpty Weight: 430 poundsGross Weight: 800 poundsFuel: 90 Pounds (15 Gallons)Pilot Size: Up to 250 pounds - 6 foot 4 inches tallBaggage 30 pounds with 250 pound pilot. More if lighter pilot (within CG limits)

Engine:

Great Plains 1835 Volkswagen Conversion - Rated Takeoff Horsepower: 60

Performance: (Prototype 1) Measured by hand held GPS, the space between runway lights with 250 pound pilot and full fuel.

Takeoff Distance: 700 feetLanding Distance: 700 feetRate of Climb: 750 fpm @ 65 mph IAS (initial)Max Continuous Cruise: 130 mph using 3.5 gallons per hour. Range 400 miles with reserves.Economy Cruise: 100 mph using 2.5 gallons per hour. Range 500 miles with reserves.Top Speed: 145 mph

Plans: CAD drawn plans, Step by Step Photo Builder's Manual and Video. Full size templates. Projected availability Oshkosh 2007

Build Cost: $7000 including new Great Plains VW 1835. Build Time: 1500-2000 hours, from plans, less with prefabricated parts.

Beta Builders Program: 9 Experienced builders are currently checking plans and constructing aircraft.

http://www.flyingmachines.cz/_english/b612/

PIK-26

Top Speed, (kilometres/hour) 190Cruise @ 3,000 rpm, (kilometres/hour) 170Fuel Consumption (litres/hour) 7Stall (km/h) with flaps 63Rate of Climb, (m/s) 3.2Take-off Distance, (m) 200Landing Distance, (m) 250Engine Used Mosler MMCBHP 35Fuel capacity (litres) 27Empty Weight, (kg) 144Gross Weight, (kg) 250Useful Load, (kg) 106Height, (m) 1.22Length, (m) 4.33Wing span, (m) 5.24Wing area, (sq. m) 6Wing loading, (kg./sq.m.) 41.6No. Completed/Flown 4Load limit, (g) +3.8, -1.5Airfoil GAW-2

SD-1

How is it built? The PIK-26 uses wood construction, made largely from pine and from the Finnish birch that the country is famous for. I was once told that the reason it is so highly prized as a material is that the short summers and cold winters make the trees grow slowly, giving a tight and strong pattern of growth rings. The skins of the PIK-26 are made of birch plywood, with the thickness varying from 0.8 mm to 2.4 millimetres. The spars are made of pine, sawn from planks. Metal parts are made of 2024T3 aluminium and 4130 steel. It is said that if you can build a wooden model aircraft from plans, the PIK-26 is no problem. The wing ribs are made of 15 mm PVC foam, and use the GAW-2 profile. The time to complete all the wing ribs is about 8 hours. The total build time for the prototype was two years and 2,298 hours, and the 2nd PIK-26 took about 1,500 hours. The construction looks fairly typical for a light wooden monocoque.

Mike Arnold's AR-5 (213 mph on 65hp)

WING DRAG:

The aspect ratio eight, 55.125 square foot, low drag wing has a taper ratio of 0.78, a NACA 65/3-418 root airfoil, a NACA 65/2-215 tip airfoil, 50 percent span, 25 percent chord, flaps, and 44 percent span, 23 percent chord ailerons. The wing area exposed outside the fuselage is 49.6 square feet, and its wetted area is 102.6 square feet. At 207 mph at sea level the Reynolds number per foot of length is 1.94 million. The average chord is 2.7 yielding a wing Reynolds number of 5.15 million. The low turbulence wind tunnel data (1) gives a profile drag coefficient of 0.0047 for the root and 0.0045 for the tip. The resulting drag area for the exposed wing is 0.228 square feet. The slight losses due to turbulent wedges at the tips, roots and landing gear intersections, plus the slight discontinuity at the flap and aileron hinge lines will probably raise the average profile drag coefficient to 0.005, giving an exposed wing drag area of 0.248 square feet. The wing loading is 12 pounds per square feet, the dynamic pressure is 109.6 psf, giving a lift coefficient of 0.109. The induced drag coefficient is 0.00053, or induced drag area of 0.029 square feet.

FUSELAGE DRAG:

The 14.5 foot long, 23 inch wide, 35 inch deep fuselage has a length to effective diameter ratio of 6 and a frontal area of 5 square feet. Mike figured the wetted area from the plans and I figured it from measurements that Mike, my son Doug, and I made during the inspection. I cross-checked to within 1/3 of one percent of Mike's figure of 83 square feet. The canopy is 19.1 inches wide and protrudes 9.55 inches above the forebody.

Corby Starlet

Length: 4,8m / 15,5 ft.

Cocpit width: 0,6m / 24 in.

Gross: 300 kg / 662 lb.Stall: 65 km h-1 / 40 mphVne: 270 km h -1 / 166 mphCruise: 200 - 250 km h-1 / 123 - 151 mphRate of climb: 2 - 9 m s-1 / 387 -1935 fpmEngine: accetable hp range is 28- 80 hp.B-612 is originaly designed for Rotax 503 [50hp]

Performance: (Prototype 1) Measured by hand held GPS, the space between runway lights with 250 pound pilot and full fuel.

Max Continuous Cruise: 130 mph using 3.5 gallons per hour. Range 400 miles with reserves.

Plans: CAD drawn plans, Step by Step Photo Builder's Manual and Video. Full size templates. Projected availability Oshkosh 2007

Build Cost: $7000 including new Great Plains VW 1835. Build Time: 1500-2000 hours, from plans, less with prefabricated parts.

Beta Builders Program: 9 Experienced builders are currently checking plans and constructing aircraft.

http://www.flyingmachines.cz/_english/b612/

Wing area: 6,8m2  / 70,7sq.ft.

Wing span: 6,9 m / 22,3 ft.

Empty: 175 kg / 375 lb

How is it built? The PIK-26 uses wood construction, made largely from pine and from the Finnish birch that the country is famous for. I was once told that the reason it is so highly prized as a material is that the short summers and cold winters make the trees grow slowly, giving a tight and strong pattern of growth rings. The skins of the PIK-26 are made of birch plywood, with the thickness varying from 0.8 mm to 2.4 millimetres. The spars are made of pine, sawn from planks. Metal parts are made of 2024T3 aluminium and 4130 steel. It is said that if you can build a wooden model aircraft from plans, the PIK-26 is no problem. The wing ribs are made of 15 mm PVC foam, and use the GAW-2 profile. The time to complete all the wing ribs is about 8 hours. The total build time for the prototype was two years and 2,298 hours, and the 2nd PIK-26 took about 1,500 hours. The construction looks fairly typical for a light wooden monocoque.

The aspect ratio eight, 55.125 square foot, low drag wing has a taper ratio of 0.78, a NACA 65/3-418 root airfoil, a NACA 65/2-215 tip airfoil, 50 percent span, 25 percent chord, flaps, and 44 percent span, 23 percent chord ailerons. The wing area exposed outside the fuselage is 49.6 square feet, and its wetted area is 102.6 square feet. At 207 mph at sea level the Reynolds number per foot of length is 1.94 million. The average chord is 2.7 yielding a wing Reynolds number of 5.15 million. The low turbulence wind tunnel data (1) gives a profile drag coefficient of 0.0047 for the root and 0.0045 for the tip. The resulting drag area for the exposed wing is 0.228 square feet. The slight losses due to turbulent wedges at the tips, roots and landing gear intersections, plus the slight discontinuity at the flap and aileron hinge lines will probably raise the average profile drag coefficient to 0.005, giving an exposed wing drag area of 0.248 square feet. The wing loading is 12 pounds per square feet, the dynamic pressure is 109.6 psf, giving a lift coefficient of 0.109. The induced drag coefficient is 0.00053, or induced drag area of 0.029 square feet.

FUSELAGE DRAG:

The 14.5 foot long, 23 inch wide, 35 inch deep fuselage has a length to effective diameter ratio of 6 and a frontal area of 5 square feet. Mike figured the wetted area from the plans and I figured it from measurements that Mike, my son Doug, and I made during the inspection. I cross-checked to within 1/3 of one percent of Mike's figure of 83 square feet. The canopy is 19.1 inches wide and protrudes 9.55 inches above the forebody.

document.xls

Page 27

Weight and BalanceSport Aviation, May 1990 Readme

Description FS WL Weight FS Moments WL MomentsEngine 12 0 156.00 1943.76 0.00Wing skins 64 29 35.00 2240.00 1027.60Spar 64 29 5.00 320.00 146.80Fuselage 68 0 22.00 1496.00 0.00Redrive 2 0 0 0.00 0.00Prop -1 0 15 -15.00 0.00Vertical Tail 129 29 8 1032.00 230.56Horizontal Tail 129 29 6 774.00 172.92Engine mount 24 0 6 144.00 0.00PAX 68 0 175.0 11900.00 0.00Main Landing Gear 38 -33 30 1140.00 -975.00Baggage 90 6 10 900.00 60.00Instruments and Radios 45 5 6 270.00 30.00Fuel 37 0 135.60 5017.20 0.00Controls 48 0 8 384.00 0.00Seats 75 0 4 300.00 0.00Battery 28 0 15 420.00 0.00Extra 0 0 8 0.00 0.00Strongback 55 0 0.00 0.00 0.00Radiator 96 6 0 0.00 0.00Spinner -2 0 1 -2.00 0.00Paint 68.00 0 15 1020.00 0.00Tail Gear 155 -11 8 1240.00 -88.00

45.65 0.90 668.60 30523.96 604.88Readme Readme Readme

Big Twin engine weights part II....

1. Valley Engineering Stock Redrive = 11.73 lbsa. Prop crush plate 6.1 ozb. Drive Belts (2.6 oz each X 2) 5.2 ozC. Mounting Hardware 6.0 ozd. Taper Bushing & hardware 5.35 oze. small pulley 13.4 ozf. Idler arm w/pulley 26.65 ozg. prop hub extension 15.1 ozh. prop drive shaft w/washer/nut 22.6 ozi. belt tensioner cam plate 10.85 ozj. large pulley w/ bearing 62.05 ozk. prop bolts 12.8 ozl. shaft shim washers 1.55 oz

2. Stock pulse fuel pump 4.65 oz

3. Complete intake w/carb 88.25 oz

document.xls

Page 28

4. Alternator magnets 32 oz

Other...

Engine block without flywheel, alternator, carb/intake. Starter installed =70.2 lbs

Engine block without flywheel, alternator, carb/intake, starter = 62.15 lbs

Notes... I have managed to literally carve the engine weight down to 100 lbs,which was my goal to keep my aircraft 103 weight compliant with the Big Twinfrom Valley Engineering. I know I couldtake quite a bit further, but for now I've met goal. Elimination of the starterand implenting an ignition system to allow hand proping will be next on my list,but for now I am out of time to further experiment. Some of the things I didwere...

1. Drilled lightening holes in big pulley2. Drilled lightening holes in idler arm3. Drilled lightening holes in belt tension cam4. Carved excess material from redrive mount plate5. Ground off all casting marks, cooling tin mounts, valve cover lettering,etc....6. Removed alternator magnets, coils and wiring/hardware.7. Drilled lightening holes in flywheel (yes, I rebalanced)8. Removed stock pulse pump - don't need it, my airframe has sufficientgravity feed system.

I plan to use a lipo battery as used in RC aircraft to start the engine usingthe stock starter system. Lipo batteries are VERY light weight and have thepunch to kick the starter right over... a 10 oz lipo should give many, manyreliable starts, be quick disconnect also.... AND for less than the price of astandard lead acid battery...

Just my 2 cents folks, take it for what its worth to you. My modifications aretruely EXPERIMENTAL and I do not suggest or imply that anyone try what I haveuntil I have some significant time put on this engine/modifications. If you dotry any of my modifications, you accept FULL responsibility for your ownactions.

Sincerely,Doug Hart

Part I ........

Hi Folks,

Here's some very good numbers on the weights of various parts on the Generac.I used a precision digital scale, calibration checked just before weights were

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taken.

Cooling tin:

1. Rh Cylinder top 4.55 oz2. LH Cylinder top 4.4 oz3. RH Cylinder - middle 8.2 oz4. LH Cylinder - Middle 8.1 oz5. Fan Cover 4.9 oz6. Fan Guard 16.5 oz7. Fan 16.65 oz8. Lower Center, aft 13.7 oz9. Aft Outer cover 46.7 oz10. Attach Hardware-all 8.75 oz

Total: 132.45 oz or 8.278 lbs

Starter, attach hardware and associated wiring: 128.8 oz or 8.05 lbs

Flywheel (with ignition magnets and alternator magnets) 18 lbs

Alternator coil,attach hardware and associated wiring: 4.64 lbs

Some observations and other findings....

The ignition has a come-in speed of 300 rpm. It IS IMPOSSIBLE to hand propthe engine to this speed. A different ignition system will have to be used inorder to eliminate the electric start or to be able to hand prop start. I amVERY interested in this option! I don't mind hand proping when I can save 8 lbson a starter and probably another 8 to 10lbs for a battery!

The alternator coils/hardware would be very easy to remove, but then noelectrical for the aircraft. As it is, it is a 30 amp alternator, which isWAAAY more than I will ever need. I'm looking at reducing this to a 3 or 5 amp. Ibelieve 2 or so lbs could be saved with this option.

The flywheel is Very heavy... the starter gear ring is cast in as part of theflywheel. I do think that some weight could be removed by the use of"lightening" holes on the face of the flywheel. Using 1" diameter holes, evenlyspaced, I estimate at least 6 lbs weightsavings, but this will require a machine shop (or someone with the right tools)to complete and rebalance the flywheel. If ignition system could be upgradedfor hand proping, the ring gearcould be cut off also. Of course, the best, and probably most expensivesolution would be an aluminum machined flywheel, I'd bet with proper design,could get all up weight to around 9 or 10 lbs…

The Stock carb that comes on the engine is ABSOLUTELY no good for aircraftuse. It does not have an accelerator pump and will hesitate, even stall theengine if sudden power demand is input!

The stock fuel pump (pulse type) is adequate for maybe a 12 inch lift, but

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absolutely no more. The Fuel tank should be kept in line or higher than theengine. Another option is to use electric pump to be ableto place tank anywhereyou want.

I think the best place to start mods/lightening would be with the starter andignition systems.

I currently have my oldest Generac (with just under 350 hours total time) downto 112 lbs w/electric start and alternator still on.

I would really like to loose at least 10 more lbs so that my aircraft can havesome extra useful load! I believe 20 lbs would be possible, but I think costwill really start going up at this point.

It's good to get back to this discussion. I had been looking at thenew B&S 810cc vertical as a possible way to get more cc's for the sameweight as the B&S 26 hp. Because of the difference in weight betweenthe Generac "Big Twin" and the small block B&S, I had assumed theGenerac was a "big block" as well. Sooooo I went to visit a smallengine builder/supplier, who happens to be an automotive engineer. Icame armed with my checkbook and intended to to buy an 810cc block andtry to stroke it somehow. I came home with a lot of information and aGenerac engine and parts.

First of all, he demystified the numbers on the Generac. They selltwo engines, both of which can be had vertical or horizontal:

The GTH 760 has a 90mm (3.54") bore and a 78mm (2.36") stroke.

The GTH 990 has a 90mm (3.54") bore and a 60mm (3.07") stroke!

But here is the secret. The GTH 990 has a dished piston to keepit's compression low enough to not detonate on regular fuel. By usingthe GTH760 engine with it's FLAT TOP piston and a GTH 990 crank, you geta 998cc engine with a 9.5:1 compression ratio. This is the engine thatGenerac sells for LP Gas, however, the Generac Engineers say that youcan run it on higher octane gasoline at 3800 RPM .................ALLDAY! Guess what I took home.

Another little factoid, There are two standards to report engineperformance. J1955 is the standard that measures the engine torque andHP with ALL the accessories attached as sold. J1940 is the measure ofperformance with least restrictive intake and exhaust and noaccessories. EVERYONE uses J1940, therefore, our applied results mayvary and any comparison to real time measurement are skewed.

`The long stroke Generac GTH 990 with FLAT TOP pistons makes 44hp @ 3800rpm continuous. It makes 66ft/lbs of torque at 3000 rpm. These areJ1940 figures. I believe this is the Valley Engineering "Big Twin".

Now to the issue of weight. There are three grades of SAE ratingfor small engines. Consumer, Commercial, and Industrial.....The Generacis Industrial. The above 998cc engine can safely be run at 4000rpm and3800 continuous. The difference between the small block B&S and the

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Generac, which has a very similar block, is in the components. I wasshown both crank and rods. The difference is startling. The heads hadbigger valves and "D" shaped intakes. These are all places where theweight is worth the increase. The other big differences are in theflywheel, fan, shroud.

I appreciate your work on weight reduction. I agree that thestarter and associated electricals are a great place to go. My interestin in the possibility that a redrive can be built with a dampener thatwill allow the prop to be used as flywheel inertia and we can loseanother ten pounds. I am also going to try to mount the redrive on theflywheel side. This will place the exhausts downstream, put all the"flywheel" weight on one end. and allow us to cut a huge chunk of shaftoff the back.

Big Twin numbersDescription FS WL Weight FS Moments WL MomentsEngine 9.3 0.0 131.0 1215.7 0.0Wing skins 63.0 29.4 15.0 945.6 440.4Spar 63.0 29.4 7.5 472.8 220.2Fuselage 77.0 0.0 21.7 1670.9 0.0Redrive 7.6 0.0 0.0 0.0 0.0Prop -2.5 0.0 5.0 -12.5 0.0Vertical Tail 130.0 28.8 8.0 1040.0 230.6Horizontal Tail 130.0 28.8 6.0 780.0 172.9Engine mount 11.0 0.0 6.0 66.0 0.0PAX 73.0 0.0 185.0 13505.0 0.0Main Landing Gear 36.0 -32.5 8.0 288.0 -260.0Baggage 98.0 6.0 10.0 980.0 60.0Instruments and Radios 45.0 5.0 6.0 270.0 30.0Fuel 38.0 0.0 67.8 2576.4 0.0Controls 51.0 0.0 16.0 816.0 0.0Seats 78.0 0.0 4.0 312.0 0.0Battery 18.0 0.0 9.0 162.0 0.0Extra 0.0 0.0 8.0 0.0 0.0Strongback 75.0 0.0 7.5 562.5 0.0Radiator 0.0 6.0 0.0 0.0 0.0Spinner -4.0 0.0 3.0 -12.0 0.0Paint 77.0 0.0 15.0 1155.0 0.0Tail Gear 148.0 -11.0 8.0 1184.0 -88.0

51.1 1.5 547.5 27977.3 806.1Readme Readme Readme

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KG LBSEngine dry Wet bits Engine wet HP Engine PSRU Prop Freight

MZ202 40 4 44 96.8 60 5850 0 350 2000Big Twin 51 4 55 121 50 5725 0 0 1000AE-50-R 24.5 3.3 27.8 61.16 50 ??? 0 1750 ???

K75 80 4 84 184.8 75 3500 0 1750 0Aerovee 66 4 70 154 100 7541.5 0 1750 1000

Revmaster 77 4 81 178.2 85 7038.7 0 350 2000Engine HP Weight Cost

Choice: Aerovee 100.00 154.00 7541.48

350 88

ReadmeTo estimate fuel weight:

HP 100.00BSFC 0.45 (Raymer Homebuilt, p18). Substitute with known value if you have it

Endurance (hrs) 4135.60 This number has been transferred to cell D15 for you…

152.7272727

84.55 kg Aircraft fuse only186.00 lbs348.00 lbs Aircraft with engine

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KG LBSEngine dry Wet bits Engine wet HP

Solo40 30 4 34 74.8 40Big Twin 51 4 55 121 50

Aerotwin 42 4 46 101.2 50K75 84 4 88 193.6 75

Aerovee 65 4 69 151.8 80Revmaster 77 4 81 178.2 85

Engine HP WeightChoice: 0 0 0

370

ReadmeTo estimate fuel weight:

HP 50.0BSFC 0.45 (Raymer Homebuilt, p18). Substitute with known value if you have it

Endurance (hrs) 4.0067.8 This number has been transferred to cell D15 for you…

152.7272727

72 kg Aircraft only157.7 lbs

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Total8200.006725.001750.005250.00

10291.489388.71

ConversionsKt mph kph Enter kt Mph Kph1 1.15077945 1.852 160 184 296

0.5399568 0.62137119 10.86897624 1 1.609344 Enter Mph Kt Kph

39 34 63

Enter Kph Kt Mph285 154 177

cc cu in Enter CC1 0.06102374 0 0

oz/ft^2 oz/yd^2 g/m^2 oz/ft^2 oz/yd^2 g/m^21 305.15 8.8 79.20 2685.32

0.00328 1g/m^2 oz/yd^2 oz/ft^2

265 7.82 0.87

oz/yd^2 oz/ft^2 g/m^220 2.22 678.11

sq ft sq m ft^2 m^21 0.09290304 21 1.95

ft in cm m ft metre cm1 12 30.48 0.3048 31.9 9.72 972.31in ft mm cm in metre cm1 0.08333333 25.4 2.54 4.5 0.1143 11.43

mm cm in ft mm cm metre1 0.1 0.03937008 0.00328084 97500 9750.00 97.50

kg/m^3 lbs/ft^31 0.06242796

kg/m^2 lbs/ft^2 kg/m^3 lbs/ft^31 0.20481614 40 2.50

kg/m^2 lbs/ft^20.51 0.104

oz lbs gm kg oz lbs gm1 28.349 0.75 21.262

gm

ozlbsgkg

lbs/ft^20.054

lbs/ft^20.139

mm in9723.12 382.80

mm ft114.30 0.38

ft in319.882 3838.58

kg

The Aerochia LT-1 - Single piece carbon wing skin

Spar calculations (Need to apply load distribution to these calculations)

Marske - struts version Spar StrutsData taken from Basic Inputs

Gross weight (lbs) 748.60 748.60Wing span (in) 242.288796314496 43.5Wing sections 2 1

Wing panel length (in) 121.144398157248 43.5Distance to wing centroid 60.572199078624 21.75

Max G 10.5 4Bending Moment (M) 238057.828208854 65128.2

Spar thickness (in) 4.28 2.5Load on spar caps 55677.125 26051.28

Rod cross section (.092x.220") 0.02024 0.02024Compression strength of Graphlite 275000 275000

Each rod can carry 5566 5566Safety factor of 50% 3710.66666666667 3710.6667

Number of rods (per cap) 16 8

Main Gear legs Spar lengthsLength 4 2 x 8ft 6 8 48Rods 8 2 x 12ft 5 12 60Length 32 2 x 18ft 5 18 90

16StrutsLength 5Rods 8 Total rod length reqdLength 40

Optimal Finess ratio (Hoerner) 3.71

DIAB plank method (NZ)

ROM's build notes:2" x 3/8" Divinycell H80 foam planks

Which rods? PlywoodThe .125 diam (3.16mm) 0.13625lbs/ft^2 (Wicks) .8mm Birch )0.2725lbs/ft^2) 1.6mm laminateThe .092x.220 (2.34x5.59mm) ie 32 ft^2 x 1/16 (1.5mm) = 5lbs

Therefore, wing skins = 4x5=20lbsEpoxy SD-1 wings weigh 54lbsWest System has HDT of only 128 deg F Spar = 3.6lbsMarske recommends Aeropoxy Ribs = 3lbsUse Nitrile gloves, not latex Wings = 26.6lbs

http://www.diabgroup.com/americas/u_literature/u_pdf_files/u_bul_pdf/Strip_Plank_TB.pdf

http://www.homebuiltairplanes.com/forums/composites/4128-strip-method-other.html

Use multiple layers of gloves and peel them off

Wash hands with vinegar, then soapWash brushes in vinegar then add lots of detergentOr wash brushes in acetoneUsed brushes are best - they don't shed hairFillers: CabosilGood bonds - cotton flox - but best is sandwiching two glass tapes between the bonded partsMolding - use playdough

Main gear calculationsAlpha degrees 12Alpha radians 0.20943951023932Tan (alpha) 0.21255656167002Height from CG (mm) 968Fwd from CG vertical (mm) 205.754751696581From datum (mm) 953.85

CF vs Glass (Marske)5.7oz twill CF = 10oz glass 5.7oz/yd^2 = 193g/m^2, 10oz = 234g/m^2Thickness of laminate = 2x its weight for CF, 1.5x weight for glassWeight of laminate = .015 x fabric weighteg: 1x lams 5.9oz CF = 5.9x.015 = .088lbs/ft^2 (1.4oz) or... 200g/m^2 = 3g/m^2CF lam = 2x strength of glass lam of same thicknessCF lam = 4x stiffer than glass lam of same thickness20oz glass lam minimum (ie 2x 5.7oz CF is equivalent)

Aerochia LT-1Weights:Front 131Left 308Right 311Total 750

Mike Arnold: AR-5 Video #2 "How its made"Uses the Marske method for bonding bulkheads to the fuse, after micro under the bulkheadUses 36-grit/80-grit sanding boardLaminate = 2x UNICanopy = 1/10 inch plexiglass. Blown. Base = glass sandwich.Flap gap = 1/16 to 1/32 inch gapUses styrofoam, 2lbs/cu ftVideo = 1:20 - the good stuffFlap control bellcrank is inside the body, behind an inspection panelHardpoints = plywood with nuts and washers on the back side. Bonded to the foam coreCentral foot or so of leading edge of flap removedHard points bonded, then false spar added. Then foam replaced, leaving hard point area freeAluminium angle bonded to foam cores as base for hingesRudder: 1.28.01Ailerons: cable operated (3/32 inch wire) to am aileron bellcrank and pushrod1:31:40 Main landing gear. Bolted (4 bolts) to the wing spar.1:32:00 Landing gearWheels 4" diam 410/4.00 tyre Off BD-4Urethane foam for the fuel tank - fuel resistantCover entire airframe with micro/epoxy, and sanded smoothThen covered with polyester primer (sprayed on). Then sanded, and painted with Imron polyurethane

Wengine mounts. Brackets (4 bolts) on pilot side of firewall.Firewall = 1/4" plywood, with extra 1/8" plywood at the engine mount brackets1:39:45Bracket = 1/8" aluminum, four bolts sensibly within the perimiter at the cornersFuel tank 1:41:001/4" clark foam. Top: glass one side, bend in place glass 2nd sideKX99 Bendix King radioStick Controls: 1:44:30Wing construction: 1:46:004x ribs used

Orion re: Balsabalsa is a firewall material sandwiched between triaxial glass and protected with a Silica fire blanket

(Need to apply load distribution to these calculations)

96120180396

3240

468

0.13625lbs/ft^2 (Wicks) .8mm Birch )0.2725lbs/ft^2) 1.6mm laminateie 32 ft^2 x 1/16 (1.5mm) = 5lbsTherefore, wing skins = 4x5=20lbsSD-1 wings weigh 54lbsSpar = 3.6lbs

Wings = 26.6lbs

http://www.diabgroup.com/americas/u_literature/u_pdf_files/u_bul_pdf/Strip_Plank_TB.pdf

http://www.homebuiltairplanes.com/forums/composites/4128-strip-method-other.html

Carbon Fibre Monarch - some notesMaterials: 5.7oz CF TWILL. 2x layersRibs laid out over corrugated plastic (flat with narrow risers)D-tube mold - Laser-cut? Then fit in 1x CF Twill and 1x Glass twill vacuum bag. Difficulty getting CF to conform to mold - hence the glassfibreD-tube - drill out most of the flat area. Smaller hole at front, larger at rear almost to edges, maybe 1/2inch between themPhenolic bushings for all fibreglass to CF fittingsLayup of spar: CF on plastic sheet. Add resin. Add 2nd plastic sheet. Work with squeegee till saturated. - then remove top layer plastic, lift and turn upside down into spar mold. - Vacuum bagging essential to get good carbon fit.Ribs:Marske: 5.7oz CF + 6oz Glass, Basically solid flat sheet with 3-D depressions. Vacuum bagged in laser cut (CNC) molds

Metric:

Marske: used 8-10in vacuum for the ribs. Lip folded over for extra stiffnessMarske: main rib = .75ozMarske: Ribs made from male foam molds, a layer of epoxy, polished and PVA - then covered with CF and vacuum baggedMarske: Cure vacuum bagged parts for 1 week before removing from mold

BeLite:CF ribs in wooden style. Flat sheet cut in water cutter

Razorback: Ditto. 2x 5.7oz LAMS @ .65 ft^2 each = 0.115lbs/rib. Ribs @ 9", so, 22 ribs Total weight: 2.53lbs

Perhaps the most amazing fact is that construction time is considerably reduced by utilizing this process. When all of the parts for the wing are ready, the entire wing can be set up, bonded (glued) and ready for covering in 3 days from start to finish. Construction of the wing is a simple process. It involves taking two pre-formed wing spars which have been created from carbon fiber and sliding 7 ribs over them. The spars simply slip through holes

SC-1 Minisport

Colomban's LucioleWooden spar + foam ribsMmmmmA very slow plane... So maybe OK

Razorback:Marske method: 3-D CF rib vacuum bagged in mold, with stiffening strips. Aiming for 15g per rib = 300g

How much static thrust is required?Orion:

Norman:

Orion:

Two part wing uses GA 37U-A315 airfoil. It consists of composite main spar with carbon caps on which are glued ribs made of extruded polystyren. It is covered with 1 mm plywood. Wingtips are made of extruded

Several fixed pitch props I've seen used for

Typically general aviation engine/prop If you want to do a really rough guesstimate

Control linkages - various sourcesSide stick http://www.homebuiltairplanes.com/forums/aircraft-design-aerodynamics-new-technology/8873-side-mounted-stick.html

I used a side stick on my Sgian Dubh with a gate bolt action to a steering column knuckle straight to the elevator horn. Since it is a flying wing the aileron controls were atached to this tube by a short lever. The leg room is much more comfortable and the nose is better streamlined.

http://www.homebuiltairplanes.com/forums/aircraft-design-aerodynamics-new-technology/8873-side-mounted-stick.html

From Autoreply (post #12)

From Wsimpson (BillSki)

HotWings: Quickie system

http://www.homebuiltairplanes.com/forums/aircraft-design-aerodynamics-new-technology/8873-side-mounted-stick.html

For my design I'm (for the moment) also using a sidestick. This has several advantages:*Less wide fuselage (you need at least 5" between your knees, compared to none for a sidestick)*Much easier setup.*No mechanisms under your seat. Gliders typically have a mess of wires, push-pull tubes and other stuff running under the seat. Making it massive (crunch-able foam) makes a lot of sense to me from the crash-worthiness perspective.

I'm aiming for a single (carbon) tube on the right side, mounted in a tunnel. It should slide forward and aft and rotate for roll. The nice thing about this is that it's not only simply, but it's fairly simple to make an adjustable stick too (it's just an extension to the carbon tube). That's a great feature single arm length greatly varies between individuals and sidestick can be VERY critical to that.

As for control feel; I've flown various gliders with parallelogram steering (the stick doesn't rotate, put only "slides" forward and aft). Feels great and you don't have G-induced pull-up. As for roll, during thermalling I usually flew those gliders with two fingers above/around the stick and two below, thus rotating your fist results in roll. Very comfortable and much more natural, compared to moving your whole hand. Low stick forces are required though.

http://www.homebuiltairplanes.com/forums/aircraft-design-aerodynamics-new-technology/8873-side-mounted-stick.html

Side sticks are sexy, but to make the control throws short enough and forces low enough, you have to work with really small control moments. The nice flying birds with side sticks, well, they have pretty small control surface chords and high aspect ratio surfaces and foils. Get out TOWS, and check it out. Flap chord is squared. On the other end of the scale, the Unlimited acrobatic birds, with great big balance horns on the rudder and elevators and huge spades on the ailerons still use center sticks and big throws.

Start with your desired control throws and stick forces, work through the mechanical advantage to your control surfaces, and that will give you your necessary control surface moments. Then you have to play with your control surface area and chord to get to reasonable control surface moment coefficients. Yes, you can work with balance horns and pivot the surfaces fairly well aft on the surface (both place area ahead of the pivot to reduce moments) but if you play near or beyond 75% aero balance, you are also playing near aileron snatch. So there are practical limits on how low you can get your moments... Which might drive you right back to a center stick.

http://www.homebuiltairplanes.com/forums/aircraft-design-aerodynamics-new-technology/8873-side-mounted-stick.html

I used a side stick on my Sgian Dubh with a gate bolt action to a steering column knuckle straight to the elevator horn. Since it is a flying wing the aileron controls were atached to this tube by a short lever. The leg room is much more comfortable and the nose is better streamlined.

http://www.homebuiltairplanes.com/forums/aircraft-design-aerodynamics-new-technology/8873-side-mounted-stick.html

http://www.homebuiltairplanes.com/forums/aircraft-design-aerodynamics-new-technology/8873-side-mounted-stick.html

For my design I'm (for the moment) also using a sidestick. This has several advantages:*Less wide fuselage (you need at least 5" between your knees, compared to none for a sidestick)

*No mechanisms under your seat. Gliders typically have a mess of wires, push-pull tubes and other stuff running under the seat. Making it massive (crunch-able foam) makes a lot of sense to me from the crash-worthiness perspective.

I'm aiming for a single (carbon) tube on the right side, mounted in a tunnel. It should slide forward and aft and rotate for roll. The nice thing about this is that it's not only simply, but it's fairly simple to make an adjustable stick too (it's just an extension to the carbon tube). That's a great feature single arm length greatly varies between individuals and sidestick can be VERY critical to that.

As for control feel; I've flown various gliders with parallelogram steering (the stick doesn't rotate, put only "slides" forward and aft). Feels great and you don't have G-induced pull-up. As for roll, during thermalling I usually flew those gliders with two fingers above/around the stick and two below, thus rotating your fist results in roll. Very comfortable and much more natural, compared to moving your whole hand. Low stick forces are required

http://www.homebuiltairplanes.com/forums/aircraft-design-aerodynamics-new-technology/8873-side-mounted-stick.html

Side sticks are sexy, but to make the control throws short enough and forces low enough, you have to work with really small control moments. The nice flying birds with side sticks, well, they have pretty small control surface chords and high aspect ratio surfaces and foils. Get out TOWS, and check it out. Flap chord is squared. On the other end of the scale, the Unlimited acrobatic birds, with great big balance horns on the rudder and

Start with your desired control throws and stick forces, work through the mechanical advantage to your control surfaces, and that will give you your necessary control surface moments. Then you have to play with your control surface area and chord to get to reasonable control surface moment coefficients. Yes, you can work with balance horns and pivot the surfaces fairly well aft on the surface (both place area ahead of the pivot to reduce moments) but if you play near or beyond 75% aero balance, you are also playing near aileron snatch. So there are practical limits on how low you can get your moments... Which might drive you right back to a center stick.

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Spreadsheet #2 ReadmeFrom Sport Aviation1/90 JGR

To Calculate Best Range Speed, Minimum Descent Speed and Top SpeedReadme

Span (ft.) 20.19Altitude (ft.) 3000Wetted Area (ft^2) 193.5Drag per ft^2 0.0048

rho (Based on cruise altitude) 0.00217513132344Best L/D (MPH) 99.51 =Best L/D 15.53Min. Descent (MPH) 75.60 =Descent (ft./min.) 494.66Max Speed (MPH) 244.78 =

To Calculate Drag Area Using Published Performance Data

Horsepower 80Altitude 3000

Top Speed (mph) 241 =Flat plate area (total) 0.7787Wetted Area (ft^2) 243.0Drag counts per ft^2 0.00320

To calculate wing area besed on type of flaps used

Gross Weight (lbs) 675Altitude (ft) 3000Speed (mph) 206 =Type of flap CL maxNone 1.50Plain 2.30Split 2.50Slotted 2.60Fowler 3.00

How to calculate your airplane's total wetted area, and its equivalent flat plate area. This is a "bonus" section - but drawn from the Roncz articles.

You will need to calculate your airplane's wetted area. Roncz (see "Sizing Wings", pg4, col1 bottom ) gives you a great method on how to estimate the FUSE wetted area. Eter your fuse wetted area in cell D56 below.

What this section on the right does is to ease the pain of working out the rest of the plane's wetted area. Enter your best guess for the H-stab and Vertical tail areas in cells D57 and D58.

The WING's wetted area is based on the airfoil % thickness, span and MAC. Select your airfoil % thickness (cell D59), enter the span and the MAC, and your WING's wetted area appears in cell D66

Finally, based on trike or tail dragger undercarriage, enter the wetted area for the undercarriage in cell D63.

Your aircraft's total wetted area now appears in cell D64

Now, depending on your construction type, you're able to calculate your equivalent flat plate area. Simply multiply your total wetted area by the drag counts per square foot, based on the table on the right.

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Fuse wetted area (ft^2)V-tail wetted area (ft^2)H-tail wetted area (ft^2)Wing airfoil % thickness

Wing span (ft)Wing MAC (in)

Wing wetted areaLanding gear wetted area

TOTAL

Composite - above averageComposite - very clean

Calculating wing Clmax with flapsClmax clean 1.50

Correction for tip losses 1.42Flap span (% span) 0.50

Flap chord (% of chord) 0.30Flap ext (% of chord) 0.30

Delta Cl-max plain 0.9

Delta Cl-max slotted 1.3

Delta Cl-max Fowler 1.69Delta Cl-max Zap Flap 1.69

Clmax flapped Zap 2.19Clmax flapped Fowler 2.19Clmax flapped Slotted 2.01

Clmax flapped Plain 1.83

You will need to calculate your airplane's wetted area. Roncz (see "Sizing Wings", pg4, col1 bottom ) gives you a great method on how to estimate the FUSE wetted area. Eter your fuse wetted area in cell D56 below.

What this section on the right does is to ease the pain of working out the rest of the plane's wetted area. Enter your best guess for the H-stab and Vertical tail areas in cells D57 and D58.

The WING's wetted area is based on the airfoil % thickness, span and MAC. Select your airfoil % thickness (cell D59), enter the span and the MAC, and your WING's wetted area appears in cell D66

Finally, based on trike or tail dragger undercarriage, enter the wetted area for the undercarriage in cell D63.

Your aircraft's total wetted area now appears in cell D64

Now, depending on your construction type, you're able to calculate your equivalent flat plate area. Simply multiply your total wetted area by the drag counts per square foot, based on the table on the right.

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Weight (lbs) 668.60E: 0.7 ReadmeHorsepower: 100 ReadmeProp Efficiency: 0.85 ReadmeProp type 3 1=Constant speed; 2=Fixed pitch cruise; 3=Fixed pitch climbFlat Plate Area: 0.929

86.4 Knots

65.6 Knots

212.5 KnotsCruise speed 184 Based on 75% power

Readme

Prop Efficiency: 0.85 ReadmeRho: 0.002175

209.2 KnotsReadme

Readme

Rho: 0.00217513Q: 99.32307

179 KnotsWing Area Required: CL max with 3-D effects of finite span, tip vortex etc taken into account

5.77 1.354.05 2.07 Readme3.72 2.253.58 2.343.10 2.70

How to calculate your airplane's total wetted area, and its equivalent flat plate area. This is a "bonus" section - but drawn from the Roncz articles.Wing wetted area table (Roncz approximation)

Airfoil thickness Multiplier12% 2.042 See Roncz Sizing Wings PDF, pg4, bottom col113% 2.048 Interpolated results14% 2.054 Interpolated results15% 2.06 Interpolated results16% 2.066 Interpolated results17% 2.072 Interpolated results18% 2.078 See Roncz Sizing Wings PDF, pg4, bottom col1

Undercarriage wetted areaTricycle 25 Roncz estimateTailwheel 18 Duncan's extrapolation

From roncz4-CG worksheet

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61.2 A reasonable estimate can ge had by taking the average of the TOP and SIDE areas, and multiplying by 3.148.5 Approx 2.1*plan area0.0 (Included in fuse area) Approx 2.1*plan area. Roncz suggests 25% of wing area as a ballpark figure

15%20.1928.5098.80

25193.53 ft^2

Drag counts per ft^2Metal - round rivets 0.0065 See Roncz Sizing Wings PDF, pg4, bottom col2

Metal - flush rivets 0.006Composite - general 0.005

Composite - above average 0.0048Composite - very clean 0.0045

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CL max with 3-D effects of finite span, tip vortex etc taken into account

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A reasonable estimate can ge had by taking the average of the TOP and SIDE areas, and multiplying by 3.14

(Included in fuse area) Approx 2.1*plan area. Roncz suggests 25% of wing area as a ballpark figure

0.821428571

15.60714286

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Spreadsheet #3 From Sport Aviation2-90 JGR

ReadmeSpeed (kts) 170

Speed (mph) 60Altitude: 1000

Cruise Weight: 669Wing Area sq. ft. 48

Wing Span, ft. 20Sweep, degrees 6.3

Max CL 2.19

Chord @BL0 (in) 28.5 Remember, BL0 = the aircraft centrelineAngle for zero lift (deg) -1.00 Get from published airfoil data

Root Chord, inches 41.9Tip Chord, inches 15.5

HORIZONTAL TAILLever arm, inches 79.4

Volume coefficient 0.65 Raymer recommends between .45 and .65

VERTICAL TAILLever arm, inches 79.4

Volume coefficient 0.045 Raymer recommends between .035 and .065

From roncz4-CGFrom Basic Inputs

From Basic InputsFrom Basic InputsFrom Basic Inputs

From Basic Inputs

From Basic Inputs

From Basic Inputs

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Mach 1, MPH 758.42 ReadmeMach Number 0.0791

rho 0.0023081CL 1.5592

Aspect Ratio 8.5000Sweep Factor 0.1104

beta 0.9969dCL/dAlpha 0.0867

Vs (kts) 44.0382CL@BL0 1.9852

Incidence (deg) 21.9087

Taper Ratio 0.3699MAC (in) 30.72

51.29

Horisontal Tail Size (ft^2) 12.07 Recommended

Vertical Tail Size (ft^2) 6.59 Recommended

MAC@BL (in)

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Spreadsheet #7From Sport Aviation, August, 1990 Readme

***Calculation of the Aerodynamic Center Along the MAC***

Zero Lift Pitching Moment: 0.02568 ReadmeCL for Alpha=4: 0.7275CM for Alpha=4: 0.03158

Aerodynamic Center: 24% Chord

***Pitching Moments due to the Fuselage/Wing Combination***

Strip Number Width (in) Height(in) Distance (in) Dist/ChordStrip in Front of Wing:

1 36.111 15.000 57.250 1.1162 42.762 18.000 40.750 0.7953 45.829 18.000 22.589 0.440

Strips just Ahead of Leading Edge:4 47.492 13.750 6.875 0.134

Strips Behind Trailing Edge:5 42.897 21.410 10.705 0.2096 29.640 26.000 34.410 0.6717 20.021 28.000 61.410 1.1978 13.884 30.000 90.410 1.7639 9.118 29.828 120.324 2.346

Chord in Fuselage: 51.29Distance from Trailing Edge to AC of Tail: 58.0

Wing Root Chord (in): 28.5Wing Tip Chord (in): 28.5Wing Area (ft^2): 48.0Wing Span (ft): 20.19Distance from Wing AC to Tail AC (in): 79.4Design Lift Coefficient: *** 0.300Wing Lift Curve Slope dCL/dAlpha: *** 0.087 Get from Roncz3-April spreadsheetDynamic Pressure at Design Point (Q) *** 99.323 Get from Roncz2-Jan spreadsheet (Q)

Mean Aerodynamic Chord (in): 28.5Downwash at Tail (degrees): 1.30dEpsilon/dAlpha: 0.3742

Pitching Moments due to Fuselage (ft-lbs) 1577.65 Foot-PoundsdCM/dCL of Fuselage: 0.4648

***Pitching Moments due to Wing Airfoil***

CM of MAC Airfoil at the Design CL: *** 0.012Pitching Moments due to Wing: 135.78

***Pitching Moments due to Center of Gravity***

FS of Center of Gravity (in): *** 45.65

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Waterline of Center of Gravity (in): *** 0.90FS of Aerodynamic Center (in): 50.13Waterline of Aerodynamic Center (in): 0.00Wing Drag Coefficient: *** 0.0055

Wing Drag, Pounds: 26.20Wing Lift, Pounds: 1429.08Pitching Moments due to Wing Lift (ft-lbs) -532.64Pitching Moments due to Wing Drag (ft-lbs) -1.98Total Moments about the CG due to Wing (ft-lbs) -398.83Moment Coefficient CM, cg wing: -0.0352

***Propeller Normal Force***

Propeler RPM: 3200.0Prop Diameter (in): 64.0Average Blade Width (in): 5.0Airplane Flate Plate Drag (sq. ft.): 0.929Airplane Max Speed (MPH): *** 212.5Number of Blades: 2.0Distance from Prop to CG (in): 1.0

Propeller Angle of Attack (deg) 3.93Blade Pitch Angle at 75% Radius (deg) 29.44Propeller Thrust (lbs) *** 92.27Rotation Speed (Radians/sec): 335.10Tc Prime: 0.019369 Readme

0.00456Coefficient of Propeller Normal Force: 0.005276Propeller Normal Force (lbs): 25.13Pitching Moments due to Propeller (ft-lbs) 2.09

***Pitching Moments due to Propeller Thrust Line***

Waterline of Thrust at FS of CG (in) 0.0

Lever Arm of Thrust Line (in) 0.90Pitching Moments due to Thrust (ft-lbs) 6.96

***Propeller Thrust for Other Conditions***

True Airspeed (mph): *** 233.7Horsepower: *** 100.0

Prop Efficiency (%) 85.86Thrust (lbs) 137.73

***Airspeed at the Tail***

Tail Dynamic Pressure (Times Airplane Dyn. Pres.) 1.042

***Power Off Neutral Point***

Horizontal Tail dCL/dAlpha: *** 0.08666 Readme

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Required tail Area:(ft^2) 12.07Fuselage Station of Tail Aerodynamic Center (in) 129.50Power Off Dynamic Pressure Ratio at Tail: 0.80 Readme

Uncorrected Power-Off Neutral Point is at FS (in) 60.69Correction for Fuselage (in) -13.25Power off Neutral Point with Fuselage (in aft of datum) 47.44

***Propeller Induced Downwash***

Thrust Coefficient: 0.00408Value of Ribner Curve "A": 0.00246Value of Ribner Curve "B": 0.25311dCNp/dAlpha for Zero Thrust: 0.00133dEpsilon, prop/dAlpha: 0.00280dCM/dCL Due to Propeller Downwash: 0.00060Propeller Downwash Moves Neutral Point (in) -0.01709

***Normal Force Contribution***dCM/dCL due to Normal Force: 0.00054Propeller Normal Force Moves Neutral Point (in) -0.01549

***Thrust Line Offset Contribution***

Perkins and Hage "K" Factor: 0.00083dCM/dCL due to Thrust Line Offset: 0.00219Thrust Line Offset Moves Neutral Point (in) -0.06

***Propwash Over Tail Contribution***

Extra "Q" Over Tail Moves Neutral Point (in) 0.44

***Power On Neutral Point***

Power Off Neutral Point (in) 47.44Corrected for Propwash (in) 47.42Corrected for Normal Force (in) 47.41Corrected for Thrust Line Offset (in) 47.34Corrected for Tail Dynamic Pressure due to Prop (in) 47.78

Final Power On Neutral Point is At FS (in aft of datum) 47.78Leading Edge of MAC is at FS (in) 43.00Neutral Point is at (% of the MAC) 16.78Center of Gravity is at (% of the MAC) 9.31Static Margin is (% of the MAC) 7.47

***Total Pitching Moments About the CG***

Due to Fuselage 1577.65Due to Wing Airfoil Section 135.78Due to Wing Lift vs CG Location -532.64Due to Wing Drag vs CG Location -1.98Due to Propeller Normal Force 2.09

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Due to Thrust Line Offset 6.96

Total Moments About the CG (ft-lbs) 1187.87

***Tail Incidence for Zero Elevator***

Tail Lift Required (lbs) 170.01Tail Lift Coefficient Required 0.17Incidence Required for Zero Elevator (deg) 3.260 Readme

***Elevator Required to Trim***

Tail Incidence Selected (deg) -1.30 ReadmeElevator Area/Tail Area (%) 100.00 ReadmeWing CL with Level Fuselage *** 0.300

Airplane Angle of Attack 0.00Tail CL per Degree of Elevator Deflection -88.2149Tail CL at the Selected Incidence Angle -0.2249Elevator Deflection Required to Trim (deg) -0.0045

***Ground Effect***

Tail CL in Ground Effect -0.169Elevator Trim Required to Trim in Ground Effect -0.004

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dBeta/dAlpha Contribution

1.262 14.280 Readme1.353 25.7711.510 33.029

4.313 77.414

0.116 2.6340.371 4.9080.663 4.3040.976 3.2651.298 1.863

ORIGINAL RONCZ numbers56.84

99.794

58.83822

97.4130.666150.76

0.185Get from Roncz3-April spreadsheet 0.0909Get from Roncz2-Jan spreadsheet (Q) 104.53

43.216855470.92486659 Note: If Tail is more than 50% of MAC

0.454434449 Above or Below Wing, Change =20 to =18

992.9289980.146362579

0.012440.0455743

106.742

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-7.52106.893-16.2390.0055

56.002470151883.719451-23.7034698-40.6904614375.65164310.010243984

240078

51.95213

275

2.47682932231.52453202

203.8335251.32741230.0200184790.0015709250.00213947321.78468495136.1542809

0

-7.52-127.73566

213117

85.11497574175.2850245

1.058764902

0.083636

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21.57257.653

0.8

120.3124216-6.32533044113.9870911

0.0057692310.00348048

0.2531903660.0008514740.0036960650.029253989-1.26426543

0.016491301-0.71270218

0.0024364-0.020195260.87277571

0.788590994

113.9870911112.7228257112.0101235112.8828992113.6714902

113.671490296

40.8902730624.8560425816.03423048

992.928998440.0455743-23.7034698-40.6904614136.1542809

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-127.73566

1376.999262

109.49494170.0573341581.610386676

1.30.35

0.185

00.0544754530.0313746580.476535732

0.070050729-0.23343672

Spreadsheet for calculating basic lift parametersfrom Sport Aviation ReadmeJGR 11-89Given...H (altitude) 0.0 rho (density) 0.00237689V (knots) 42.0 V (ft./sec) 70.938W (weight) 675 V (MPH) 48.384

If you know this... Calculate this...CL (lift coef) 2.34 S (wing area) 48.234

If you know this... Calculate this...S (wing area) 50.0 CL (lift coef) 2.257339

If you know this... Calculate this...S (wing area) 50.0 V (knots) 88.249CL (lift coef) 0.511300

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Spreadsheet #6From Sport Aviation, June, 1990

Readme

Altitude: 3000.0Wing Chord, inches: 33.0Speed, MPH: 206.0

Rho: 0.002175131 Slugs per Cubic FootMu: 3.68322E-07 LB-SEC/SQ. FT.Temperature: 48.30152 Degrees FReynolds Number: 4.907814834 Million

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Sport Aviation January, 1991

Root Chord (in) 36.0Root Buttline (in) 36.0Root LE @FS (in) 101.81/4 Chord @ FS (in) 110.8

Tip Chord (in) 36.0Tip Buttline (in) 36.0Tip LE @ FS (in) 77.21/4 Chord @ FS (in) 86.2

Wing Span (ft) 20.0Taper Ratio 1.01/4 Chord of MAC (in) #DIV/0!Buttline of MAC (in) 36.0Panel Area (ft^2) 0.0

Panel # Panel Area BL of MAC 1/4 Chord BL Moment 1/4 Chord Moment1 19.1 12.3 115.8 233.9 2210.92 10.9 31.7 115.1 344.2 1248.63 66.1 97.1 100.5 6420.1 6648.1

Wing Area (ft^2) 96.07Average Chord (in) 57.64BL of MAC at (in) 72.841/4 Chord @ FS (in) 105.21LE MAC @FS (in) 90.80

Raymer's spreadsheet - enhanced and customised by Duncan MeyerNOTES:Green cells: Enter own values Datum = rear surface of firewall

Yellow cells: Calculated - don't fiddle NB Engine power and weight are tied together for my chosen engines

Blue cells: Constants - don't fiddle Ignore my calculations in D14 and enter own values as required.

Inputs Calculated ValuesStall speed (kts) 42 Stall speedTakeoff air density (rho) (slugs/ft^3) 0.002377 Dynamic pressureWing CLmax 2.41 Wing loading (W/S)power loading (lb/hp) 9.70 Cruise speed

Dynamic pressureWing loading (Cruise)

Engine Power (hp -each) 75 Wo

Number of Engines 1 Wing Area

Engine weight 185 Target weight of landing gear (20% Wo)Swet/Sref 4.659 Aircraft empty weightCfe 0.0055 CdoAspect ratio (Awing) 8 K (=1/piAe)Cruise air density (slugs/ft^3) 0.00218 W/S cruiseCruise velocity (kts) 155 Cruise velocity

Drag due to lift (K) 0.071 Dynamic pressure

L/D cruise

Engine SFC (lb/hour /bhp) 0.45 Engine SFCProp Efficiency (cruise) 0.78Range (nmi) 150 Range

Breguet ExponentWf/Wo

Fuel allowance (%) 6 Wf/Wo with allow.Empty Weight constant "a" 0.92603478231Weight - crew 81.8 180Weight - Passengers 0.0 0Weight - payload 4.5 10 See Sizing Graph sheet for Wo Results

Wing taper ratio 0.5 Wing SpanWing LE (ft from datum pt) 582.3 1.91 Root ChordCG as % of MAC FWD 28% Tip Chord

REAR 29% Mean Chord (C-bar)

Aer

od

ynam

ics

H-Stab LE from datum 2461.00 8.07 Spar depth

H-Stab chord 685.50 2.25

H-Stab quarter chord 171.5 0.56

H-Stab 1/4 chord from datum (Xtail) 2632.5 8.64 Stability numbers

H-Stab tail arm 1794.9 5.89 Spar position (from datum)

H-Stab span 2423.0 7.95 Sht (h-stab)

Wing 1/4 chord from datum (Xwing) 837.6 2.75 Svt (tail)Wing LE to H-Stab LE 1878.7 6.16 AR (h-stab)Cht (volume coeff) 0.8 CGVertical tail arm 1794.9 5.89 % of MACCvt (volume coeff) 0.05 Static MarginTip of spinner to datum 1291.00 4.24Wfuselage 609.50 2.00 Main gear pos from datum (12%)Lfuselage 4745.00 15.57 CG movement (full/empty gas)Kdownwash 0.5 Average CG

L/D cruise

Win

g d

ata

Clmax clean 1.5 GA37A315

Win

g

Lo

adin

gW

o -

kno

wn

en

gi

ne

Wo

Siz

ing

to

a r

ang

e re

qu

irem

ent

(en

gin

e is

no

t ye

t se

lect

ed)

Win

g

Geo

met

ry

Win

g d

ata

Correction for tip losses 1.425 Approach speedFlap span in % span 0.6Flap chord % of chord 0.4Flap ext in % of chord 40% StallDelta Cl-max plain 0.9 Plain

Delta Cl-max slotted 1.3 SlottedDelta Cl-max Fowler 1.82 FowlerDelta Cl-max Zap Flap 1.82 ZapClmax flapped Zap 2.41Clmax flapped Fowler 2.41Clmax flapped Slotted 2.13Clmax flapped Plain 1.91

Pro

p

Prop diameter 2-blade 5.4Prop diameter 3-blade 4.4Estimated power loading 12.15

Datum = rear surface of firewall NB It all boils down to the Stability Numbers (F42)

NB Engine power and weight are tied together for my chosen engines If these are wrong, the plane won't fly

Ignore my calculations in D14 and enter own values as required.

Calculated Values Other Factors Used Equations (from book)(ft/sec) 70.9(psf) (q) 5.98 S(exposed)(psf) 14.40 Airframe top 16 S(wet) Foam area(ft/sec) 261.80 Airframe side 23 61.23 62.8

(psf) (q) 0.0021874.53 Wings 50.52 120.0265

(lb) 727.50 H-stab 17.89 37.56159

(sq ft) 50.52 Rudder 3.84 (incl in tail)

36.375 Tail 4.04 16.548359.0 163.2 Swet 235.4

0.0256 Sref 50.50.0531 Swet/Sref 4.66

14.1(ft/sec) 261.8

(psf) 74.5

6.88

(lb/sec /bhp) 0.000125e (Oswald) 0.75

(ft) 911400 Wcruise/Wo 0.980.03860.0619 Non-cruise weight allowance 0.9750.0656

Empty Weight exponent -0.09

Header tank 30.0 (lbs) LitresSee Sizing Graph sheet for Wo Results 5.0 (gal) 22.5

6127.6 20.10 Wing tank 120.0 (lbs) Litres1021.3 3.351 20.0 (gal) 90510.6 1.675 112.5794.4 2.606 @12l/hr 9.375 hrs

1838.3 6.0311

Designed Metric (mm)

2.95 900.00

(sq ft) 17.89

(sq ft) 8.623.53

32.0 33.028% 32%

Front Aft#REF! #REF!

Main gear pos from datum (12%) 620.5CG movement (full/empty gas) 1.1

32.56.88

q

KSW

SW

qCD

L

D //

1

0

2

2

1StallVq

LqCS

W

ref

wetfeD S

SCC 0

AAK

424.0

75.0

1

DL

cR

fp

bhp

eWW /5000 975.01

000 1 WWWW

WWW

FE

payloadpeople

09.000aWWWE

55 kts63 mph

101 kph42 kts48 mph

78 kph

NB It all boils down to the Stability Numbers (F42)

Equations (from book) Misc Useful Calcs

q

KSW

SW

qCD

L

D //

1

0

2

2

1StallVq

LqCS

W

ref

wetfeD S

SCC 0

AAK

424.0

75.0

1

DL

cR

fp

bhp

eWW /5000 975.01

000 1 WWWW

WWW

FE

payloadpeople

09.000aWWWE

Climb, Cruise, & Max Speed Calculations for Simplified Aircraft Design for HomebuildersUse this sheet for performance calculations after you have drawn your design and measured its geometry.

V kts V ft/sec CL50 84.45 0.44038166 0.59 180.597987 144.47839 7.755835219 1.85673063

100 168.9 0.88076333 0.8 122.439313 97.9514506 31.02334088 0.46418266150 253.35 1.32114499 0.85 86.7278469 69.3822775 69.80251697 0.2063034200 337.8 1.76152666 0.82 62.750148 50.2001184 124.0933635 0.11604566250 422.25 2.20190832 0.8 48.9757253 39.1805802 193.8958805 0.07426923

Read Cruise speed where cruise thrust line crosses drag line and enter in D32 on previous sheet

Input adjusted values

Advance Ratio J

Propeller Efficiency

Total Thrust lbs

Cruise Thrust lbs

Dynamic pressure q

100 110 120 130 140 150 160 170 180 190 20050

100

150

200

250

300Maximum & Cruise Speed

Total Thrust

Cruise Thrust

Drag

Velocity - kts

Th

rus

t o

r D

rag

-lb

s

50 70 90 110 130 15010001250150017502000225025002750300032503500

Rate of Climb - Sea Level

Velocity - kts

Clim

b -

fp

m

Climb, Cruise, & Max Speed Calculations for Simplified Aircraft Design for HomebuildersUse this sheet for performance calculations after you have drawn your design and measured its geometry.

Equations (from book)

CD Drag lbs Climb (fps)0.27622203 72.1524599 1156.098220.04761309 49.7484065 1549.862510.03538298 83.1820753 113.4005320.03332503 139.278267 -3263.353510.03276265 213.949798 -8793.64221

Read Cruise speed where cruise thrust line crosses drag line and enter in D32 on previous sheet

50 70 90 110 130 15010001250150017502000225025002750300032503500

Rate of Climb - Sea Level

Velocity - kts

Clim

b -

fp

m

)( 20 LD KCCqSD

qS

WC cruiseL

2

2

1Vq

DLW

TVVv

/

1

Sizing Calculations

Wo guess We/Wo We Wo calculated200 0.2612 52.2 298.2250 0.2560 64.0 295.8300 0.2518 75.5 293.9350 0.2484 86.9 292.3

If sizing graph lines do not cross, change Wo-guess values above.

Enter Wo from graph (lbs) 295Pick engine with horsepower of at least: 92

Power of Selected Engine: #REF!Calculated Power Loading: #REF!

Pick Wo from graph, where the two lines cross. Enter this value below to find the minimum horsepower engine for your power loading.

Now find a suitable engine of at least this horsepower and enter its power below:

Now go to sheet 1 and enter the power of your selected engine and the power loading calculated above in the boxes this color. 180 200 220 240 260 280 300 320 340 360

0

50

100

150

200

250

300

350

400

Sizing Graph

Wo Guess

Wo

Ca

lcu

late

d

180 200 220 240 260 280 300 320 340 3600

50

100

150

200

250

300

350

400

Sizing Graph

Wo Guess

Wo

Ca

lcu

late

d

180 200 220 240 260 280 300 320 340 3600

50

100

150

200

250

300

350

400

Sizing Graph

Wo Guess

Wo

Ca

lcu

late

d

Landing gear design spreadsheetWritten by Neal Willford 1/24/04 for Sport AviationBased on methods presented in "Design of Light Aircraft" by Richard Hiscocks, "The Landing Gear" by Herb Rawdon and "Analysis and Design of Flight Vehicle Structures" by BruhnFor SOLID, round tapered cantilever spring gear with single deflectionGear drag load is accounted for in bendingThis spreadsheet is for educational purposes only and may contain errors. Any attempt to use the results for actual design purposes are done at the user's own risk.Input required in yellow cells

Maximum Vertical Speed Calculation Tire GeometryLanding weight: 718.60 lbs Tire outside diameter: 13.6Wing area: 47.96 sq ft Flat tire diameter: 8.2

Tire width: 4.9Tire pressure: 36

Gear Geometry ( see Figure )Gear span: 21.58 inchesGear height: 20.00 inchesGear side view depth (positive aft): 6.00 inchesDist. from leg bend to wheel C/L: 3.50 inchesLeg length in mounting socket: 8.00 inchesGear diameter at side of fuselage: 1.38 inchesGear diameter at axle: 0.77 inchesGear leg true length = 30.03 inches

Landing Gear Capability. Margin of Safety should be at least 0.50 for Limit Energy Condition.Limit Reserve Max vertical landing speed =

Energy Energy Max vertical landing speed =Condition Condition Aft component of gear load, K =

Vertical gear load per wheel (lbs) 1468 1643 Tire deflection at limit energy conditionGear drag load per wheel (lbs) 367 411 Tire deflection at limit energy =Gear load factor (ng) 4.1 4.6 Max. possible tire deflection =Limit inertial load factor (n) 4.8 5.6Tire + gear vertical deflection (in) 7.6 8.5Combined Margin of Safety 0.84 0.64Drop height (inches) 13.9 20.1Effective weight for drop test (lbs) 550 505% of load of on main wheels at gross weight and C.G. while a/c sitting on the ground:Main wheel tire + gear leg deflection while a/c sitting on the ground =Additional gear + tire deflection for reserve energy condition =

Background calculationsGear leg deflection constant calculation assumes that the gear leg has constant area from end of leg to wheel center line

Section Local area I slopeM Dia (inches) sq. in. in^4 M/EI

1 34.90 1.38 1.48 0.1755 1992 33.32 1.34 1.42 0.1598 2093 31.74 1.31 1.35 0.1451 2194 30.16 1.28 1.29 0.1316 2295 28.58 1.25 1.22 0.1189 2406 27.00 1.22 1.16 0.1073 2527 25.42 1.18 1.10 0.0964 2648 23.84 1.15 1.04 0.0865 2769 22.25 1.12 0.99 0.0773 288

10 20.67 1.09 0.93 0.0689 30011 19.09 1.06 0.88 0.0612 31212 17.51 1.02 0.82 0.0541 32413 15.93 0.99 0.77 0.0477 33414 14.35 0.96 0.73 0.0419 34315 12.77 0.93 0.68 0.0366 34916 11.19 0.90 0.63 0.0318 35217 9.61 0.87 0.59 0.0275 34918 8.03 0.83 0.55 0.0237 33919 6.45 0.80 0.50 0.0203 31820 4.87 0.77 0.47 0.0173 28221 0 0.77 0.47 0.0173 0

constants for E and load = 1Angle of gear leg from horizon =

Gear Leg Deflection constant = 164324 Limit energy drop ht =

Gear Stub Deflection constant = 530 Multiplier if drag load in bending =

Energy required and available calculationsGear load factor (ng) 0.9 3 5Vertical load per wheel (lbs) 323 1078 1796Tire deflection (inches) 0.46 1.54 2.57Load normal to gear leg (lbs) 249 829 1381Deflection of gear normal to leg (inches) 1.4 4.7 7.8Deflection due to gear stub (inches) 0.2 0.7 1.1Total gear leg deflection (inches) 1.6 5.4 9.0FAR vertical sink speed (ft/sec) 8.7 8.7 8.7Energy due to sink speed (in-lbs) 5017 5017 5017Energy due to gear and tire stroke (in-lbs) 200 666 1110Total limit energy of landing (in-lbs) 5217 5683 6127Reserve energy (in-lbs) 7225 7225 7225Energy absorbed by tires (in-lbs) 70 782 2173Energy absorbed by gear legs (in-lbs) 201 2231 6197Total energy provided by gear (in-lbs) 271 3013 8371Total gear + tire deflection 1.67Torsion moment on gear leg due to sweep and drag load =

Based on methods presented in "Design of Light Aircraft" by Richard Hiscocks, "The Landing Gear" by Herb Rawdon and "Analysis and Design of Flight Vehicle Structures" by Bruhn

This spreadsheet is for educational purposes only and may contain errors. Any attempt to use the results for actual design purposes are done at the user's own risk.

Material properties of some materials used for gear legsinches Ultimate Modulus Materialinches strength Elasticity Densityinches Material Ftu (psi) E (psi) (lbs/in^3)psi 4340, 5160 and 6150 Steel 220000 29000000 0.286

2024-T3 Aluminum 70000 10500000 0.0986AL-4V Titanium 130000 16000000 0.160*** Steel Ftu are heat treated values ***Gear Leg Material PropertiesModulus of elasticity, E: 29000000 psiUltimate tensile strength, Ftu: 220000 psiMaterial density: 0.286 lbs/in^3Approx gear weight = 24.9 lbs

Max vertical landing speed = 8.7 ft/sec (for limit energy)Max vertical landing speed = 10.4 ft/sec (for reserve energy)Aft component of gear load, K = 0.25Tire deflection at limit energy conditionTire deflection at limit energy = 2.10 inchesMax. possible tire deflection = 2.70 inches

90 %1.67 inches6.81 inches

calculation assumes that the gear leg has constant area from end of leg to wheel center line tapered gear slope = 0.0201476875max Mr/I = 166 187189 209425 Min M.S. =

deflection integrated L.E. R.E. L.E. R.E.deflection Mr/I Mr/I Mr/I Tr/Ip Tr/Ip

0 0 137 154377 172716 8811 9857322 254 140 158119 176902 9452 10575660 1030 143 161859 181087 10158 11364

1013 2352 147 165570 185238 10935 122341385 4247 150 169215 189316 11794 131951773 6742 153 172749 193269 12745 142592180 9867 156 176114 197034 13801 154412606 13649 159 179239 200530 14977 167573052 18121 161 182034 203658 16291 182263516 23311 163 184387 206290 17763 198734000 29250 165 186157 208270 19418 217254502 35969 166 187165 209399 21285 238145022 43496 166 187189 209425 23399 261795557 51855 165 185943 208032 25803 288686103 61069 162 183069 204816 28548 319396657 71153 158 178106 199263 31696 354617211 82111 151 170465 190715 35324 395207754 93937 141 159387 178321 39528 442248273 106601 127 143887 160979 44427 497048747 120051 109 122676 137249 50169 561299434 164324 0 0 0 50169 56129

Angle of gear leg from horizon = 0.729 radians Top view gear length = 22.40 inches13.9 inches front view gear angle = 0.75 radians

Multiplier if drag load in bending = 1.03 side view gear angle = 0.29 radians

limit energy reserve energy4.1 4.6 limit energy slope = 1.6

1468 1643 limit intercept = -8120.72.10 2.35 gear energy slope = 0.131129 1263 gear energy intercept = 673.76.4 7.2 Energy where req'd limit & gear/tire match = 5924 in-lbs0.9 1.07.3 8.28.7 8.7

5017 5017 Max allow. bending stress = 366916 psi907 1015 Estimated Fo = 209880 psi

5924 6032 approximate Fs = 132000 psi 7225 72251452 18174140 51825592 70007.57 8.474497 5031 in-lbs

0.84 0.64L.E. R.E.M.S. M.S.1.35 1.101.29 1.051.23 1.001.18 0.951.13 0.901.08 0.861.04 0.820.99 0.780.96 0.750.92 0.720.89 0.690.87 0.670.85 0.650.84 0.650.84 0.640.85 0.650.87 0.670.90 0.690.94 0.730.98 0.771.63 1.35