Instructions for the AvmechaniCalc

The best way to learn this program is to open up each one of the worksheets in turn and play with them. Enter some data, get some results, store some files. You can’t blow it up, and you can erase any test files you make at any time. You’ll find out that it’s far faster and more accurate than looking things up in the 43.13, and you won’t need to "wing it " anymore when doing a repair.

Main Menu and general Instructions:

If you have difficulty scrolling any worksheet to its bottom or top, particularly the 337 forms, you are probably using a small screen computer such as a laptop. To scroll fully with such a monitor, place your mouse cursor over an empty area on the screen (the desktop background) and right click once. This will bring up "my computer" screen properties, click on properties at the bottom of the dialog box and select the *settings* tab. Set your screen resolution higher, click Apply and then OK to exit. Your will be able scroll the worksheets fully. You will see that your monitor now is virtually larger, and its display area is actually larger than the monitor edges. If you just move your mouse cursor to the edges of the screen you will be able to "push" the screen display further out at all 4 sides.

To perform the various calculations and functions, Click on any menu entry, or hit the *TAB* key on your keyboard to reach any menu item, then press *Enter*. *Shift*/*Tab* will reverse the selection cycle

Each command button also has an underlined *hotkey* associated with it. Press *Cntrl/Alt and the underlined key to activate a *hotkey* command.

In general, the above instructions are applicable to the controls for each of the programs.

In each program, Enter data only in white boxes, grayed data boxes are calculated for you.

Each program has a *?* button to view help instructions particular to it. It's the first Tab selection, so hitting the *Enter* key as soon as the program page opens will bring up the instructions.

Most data entry boxes or results boxes in each worksheet have a "help tip" associated with them. Just move your cursor over the box with the mouse and the help tip will appear.

You may have as many programs or instruction pages open as you like.

If you want to close all open worksheet but remain in the program to start a new project, got to the file-close open worksheets menu selction at the top of the main page.

When finished with all your work, and after saving any necessary files you can exit this program by either clicking the *Close all functions* key at the bottom of the Main Menu page to exit this program, or selecting the "file" menu at the top of the menu page and selecting "exit"

You can close any single page by clicking the red *X* at the upper right-most corner, as in all windows programs.

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Aircraft Owner and Job Info:

This worksheet allows you to enter the AC owner’s name, "N" number, and all the usual data that you need to keep for recording purposes, as is applicable for each task that you may perform with the AVmechaniCalc. You can also enter any notes pertinent to each job in this worksheet, or make up a work order /invoice in the notes section.

Within this worksheet, you must also select which worksheets to save to disk your aircraft/owner info, and any of the data from any worksheet that you have used for a job. Just check the selection boxes in this worksheet for each of the task worksheets that you may want to save. After checking your selections, click on the "file" menu at the top of the main menu page, and select the "save option. Name and store the file in whatever directory you choose. There is a suggested folder in the AvmechaniCalc folder named "work files". Which contains sample worksheet files for you review. You can store to this folder or make a new one of your choosing Each file uses the suffix ".AVM.

You can retrieve any saved file by going to the "file" menu and selecting the "open" option. Any worksheet that was previously saved into the file will be automatically opened, and the data entered into the worksheet cells—you don’t have to remember which worksheets you saved.

If you are working within any worksheets and would like to apply only the aircraft data and owner info from a previously saved file to the current job at hand, but not overwrite the worksheet’s current working data, just click on the "apply" button at the top right corner of this worksheet. The file open box will appear to allow you to select which file to apply. Although this file open dialog box appears the same as the usual file save dialog, when you hae clicked the "apply" button it will not overwrite the currently open worksheets, it will only overwrite the data on the Aircraft Info sheet.

Printing your worksheets:

The data for any worksheet may be printed for review and taken to the job site as a work note. Enter the "file" menu at the top of the Main Menu page and select "print":. A list of print options will be displayed. Choose which worksheets you would like printed by clicking the selection boxes, then click "print". Selections must be checked in oreder to print. Only the worksheets selected will be printed.

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Weight and Balance worksheet program:

GENERAL INSTRUCTIONS:

Enter weights and Arms in appropriate column. DO NOT ENTER MOMENTS, they are calculated for you.

If calculating empty CG, from scale weights, enter right wheel weight and Arm in first row, left wheel wgt. and arm in second row, nose or tail wheel wgt. and arm in third row. Click "get CG"

If you inadvertently weight an aircraft with Fuel or another undesired item on board, simply enter that items’ arm as a the actual station number where it is located and its weight as a negative number and Click "get CG" to re-calculate the empty CG. It is of course important to enter the precise weight and arm in this case in order to arrive at an empty CG.

If calculating CG changes as a result of loading or equipment changes, enter aircraft EMPTY weight and CG in first row, changes in other rows.

Use normal plus or minus sign conventions for negative weight and arms then Click *get CG* to calculate.

If you have multiple standard loading configurations, enter those items and arms, and save a file for each configuration to simplify your future data entry procedures. Any desired file can be retreived for future review and modification.

You can Make changes at any time to any entries and re-calculate with *get CG* . You can type over any prior entries to change them. Enter data only in white boxes, grayed data boxes are calculated for you.

You can clear the entire form by clicking the *Clear Form* button--this will clear all weight and balance entries

you can also navigate by pressing the *TAB* key and cycling thru the selections and commands. Each command button also has an underlined *hotkey* associated with it

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Weight and Balance for a specific aircraft CG profile:

If you have installed any specific aircraft weight and balance configuration files, you can apply them by clicking *Apply a weight and balance specification*. This allows the weight and balance data entered to be evaluated against the CG/gross weight profile for a particular aircraft type. When *Get CG* is clicked, the program will now evaluate the CG against the particular profile and determine whether the weight and balance data as entered is within the aircraft profile, or too far forward, too far aft, or overweight. There are several sample profiles installed with this program located in the ..AvmechaniCalc\wgt-bal config files folder—the folder just below the one where this program is installed. Apply them and test their usefulness. They are accurate profiles from the aircraft data sheets so can be used in your work, should you work on any of those aircraft.

Aircraft specific weight and balance files for just about any aircraft are available from Monoposte, call 908-419-7560 or email info@monoposte.biz.

Tell us what make model and serial number of aircraft. They are priced at $5.00 per aircraft, 3 aircraft files minimum order. 5 files for $20.00, 10 files for $35.00, 20 files for $50.00, 30 files for $70.00. 40 files for $83.00. Buy a bunch and sell printed profiles and load listings for your customers.

Printing a Weight & Balance chart:

You can display a line chart with the CG plotted for the particular data by clicking *Display a Weight and Balance line chart*. This chart may be printed once it's displayed by clicking the button *Print this Chart* on the line chart itself.

Continuation sheets for additional wgt & bal items:

When you have more items to enter on a sheet for wgt & bal calculations than the sheet will hold you can easily create multiple sheets --as many as necessary-- by using the *carry forward* capability.

Each time you compute totals by clicking *get CG*, those totals are saved in the *continuation...* boxes.

To compute more items than each sheet will hold, after each *get CG* calculation, click on *Carry Tls Fwd*. This will clear the previous line entries while preserving the totals and carrying forward the prior totals to the first line of the sheet.

Now, you can make all entries as usual in the remaining rows and *get CG* again for the new total and CG.

This can be repeated for as many times as required.

Don't worry about the continued appearance of the continuation totals in the bottom boxes, they do not effect the Get CG* calculation UNLESS you click * Carry Ttls Fwd.

This process is similar to what is done for a normal Loaded CG calculation, where you enter the known baseline CG of an airplane in the first row, and add modifications to that CG by entering weights and Arms and calculating the new CG.

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Calculating Ballast requirements for an aircraft:

If ballast is required for an aircraft, the weight amount of the ballast may be computed with the Ballast program worksheet.

First make an estimate of where (at what arm) in the aircraft to mount the ballast. This is usually limited by available secure places in which to do so.Then enter the current aircraft weight, current CG, the desired CG, and the distance in inches between the assumed ballast location and the old CG. CLick *Compute Weight* to get the ballast weight required.

Calculating Weight or Baggage shifts to adjust CG:

Enter the program to " make CG change by moving ballast or baggage". This worksheet will give you the amount of weight to shift from one location to another to adjust CG. It is used when the CG needs to be shifted due to loading aarangements, or airframe modifications, and it eliminates the need to make repetetive entries and multiple calculations in the Main weight and balance program. You only need to know the current AC weight, the curent CG, where the weight is to be shifted from, and where weight is to be shifted to.

You enter the AC weight and current CG in the appropriate boxes, the desired CG, the arm that the weight is to be shifted from, and the arm that the weight is to be shifted to. Click the compute button and the amount of weight is returned in the answer box.

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Hydraulic System Calculations:

To find the total pressure at a slave cylinder when master cyl. dia. and slave cyl. dia. are known,

Enter the diameters in the labeled boxes, the estimated actuating force in Lbs, click *get slave force* "

To find the pump pressure required to lift or move an object of known max. weight, enter the weight to be moved in the lbs. total force required * box, and the inside diameter in inches of the desired Hydraulic Cylinder and click *get pump Psi*. the required Psi will be given in the labeled box

To find the pump pressure required to move an object by pulling it with a cylinder (cylinder retracting), enter the required information in the boxes (this time you neeed to also enter the pushrod diameter), and click * get Pump psi

You will also need to know the fluid capacity requirement of the system. TO find that, enter the cylinder lengths, their diameters, all in inches, in the boxes provided. You may enter up to 7 cylinder sizes. Enter the length and diameter of the system tubing and hoses in their boxes. The number of cylinders and the number of lines do not have to match. There are 7 boxes provided for tubing sizes so that you can enter various different diameters if required. Lengths of same diameter of course can be combined to save entry box space.

Click *get total capacity* and the capacity in quarts of each cylinder and line will be given in their total rows, as well as the total system capacity in quarts in the named box for total system capacity. "

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Rivets per Inch:

Select this menu item to get the rivet number and sizes required for any job. No calculations required, just enter the type of metal alloy to be riveted, select the type of structure to be repaired, and the rivet size, and the number of rivets required per inch will be calculated, and well as the structure type percentage modifiers. Total number of rivets required for a given repair size and length of rivet will be calcualted as well. The correct rivet diameter for thickness of metal and whether the repair will fail in rivet shear or not is verified.

Highlight rivet size from first list, *select rivet size..*

Highlight metal thickness from second list, select 1 of the 3 metal alloy types from top frame Then click *Get # rivets*

If the rivet size selected is optimal, the *joint will fail in rivet shear* " _

will answer *yes*. If not, *No* will be returned. This is not the optimal condition, a smaller rivet size should be selected if possible.

If your joint is not a primary structure, you can then select a rivet count modifier from the next frame below according to your type of structure splice. Then, click *get # of rivets* in this frame for your modified rivets per inch.

You can then calculate the total rivets required as a function of your total splice width in the frame below then click the total button.

The length of rivet required can then be obtained in the right side frame.

Enter the sheet thicknesses in the boxes (up to 3 sheets), the rivet diameter comes from pre-calculated figure Click *get length* for total required length. Select the closest larger standard rivet and cut to length.

The worksheet can be printed by clicking on the "file" menu selection on the main menu page, then selecting print.

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Finding Electrical wire gauge:

The prime advantage of this program is that you can enter lengths to any decimal value, and amps to any decimal value in order to get the easiest to handle smallest possible gauge acceptable.

you are not limited to the amperage and range jumps given in the charts in the 43.13-1B. The program uses the same calculation methods as used in the 43.13, but extends them to all possible values without error-prone interpolation.

Section 1. Enter system voltage, desired wire length, desired amperage and max allowed voltage drop in the appropriate boxes. --max allowed voltage drop for 12 V is 0.5, for 28 V is 1.0, for 115, 4 V. for 200, 7 V

Select the appropriate button above for continuous or intermittent current and then click *Get Gauge* for your result ---- remember that 2 minutes is the FAA definition of .

You now must check the wire gauge selection for operational derating factors-- it is rare that a wire gauge calculated at first will meet the derating standards unless it just happens to fall in the low end of its allowed amp rating particularly since the FAA figures (used in this program) are calculated at 20 deg. C conductor temp, which is usually unobtainable in practice.

Section 2. To derate the wire, enter the max temp rating of the wire in the first box of the second frame

Then enter the expected worst case ambient temp

enter the number of wires in the bundle -- from 1 to 41 allowed.

then select the expected percentage of load experienced by the bundle in the selection box ,

then select the worst case altitude the aircraft can reach and click *Get Derated Amps*

All the derating factors for your info are then shown in the righthand boxes. the important ones are the derated length and the Bundle derated amps. the bundle derated amps figure is the final allowable figure after all derated factors are taken into account.

Compare the derated bundle amps and max derated length with your installations's needs. If the derated figures are less than your application requires, go to the *new gauge* section just below, and enter a new trial gauge and click *click to try new gauge* The newly calculated derated number will be shown in the boxes above where the first derating go-round were displayed. If the derated figures are still too low, enter another gauge larger and try again.

Section 3. Instructions for sending values to the Bundle Analyser.

Once you're satisfied with the values, you can then send them to the Wire Bundle Analyzer Program by using section 3 at the bottom of the page.

You build your initial bundle by selecting *Send values to Sequential list #'s ...* and then entering your desired starting number in the box right of the selection button, usually at No. 1, but you may start anywhere.

Every time you send a value, the starting list number is automatically incremented to the next one _

You can replace an individual wire # from the Main Electrical Page by selecting *Send value to specific wire # in Analyzer* and entering the wire # to replace in the box.

wire values sent to a specific wire # are highlighted in light blue to remind you so that you don't accidentally overwrite them if you later enter items sequentially.

At anytime you can open the bundle analyzer program from the main menu. The values you send to the bundle analyzer will be updated whether it is open or not.

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Wire Bundle Builder and Analyzer

Wire bundles should usually be built up from the Electrical Main Page and sent to this page for analysis.

That's done by clicking on *Send values to Bundle Analyzer* at the bottom of the Main Electrical Page, after selecting the sequential option alongside the button and entering *1* as the starting list number

Every item and click control key has a help tip attached to it. Just move your mouse over an item to view tip.

Then, loading analysis can be done here by first comparing the *design Amps*, *design wire length* to the *max. Amps* and *Max. length* entries to ensure that the *design Amps* is less than the *Max. Amps*. If not, enter a new, larger trial gauge size at the bottom of this page and its wire # to increase its capacity. After clicking, the changes will be immediately reflected on this page in the appropriate wire # entry.

When you have visually compared all wire amps and lengths for compliance with Max. ratings shown in the appropriate columns, then at the bottom of this page, enter the bundle derating percentage (no decimal point) and click *Sum Bundle*.

This will give you the total design Amps and the Max rated amps for this bunbdle. If the Total Amps is less than the Max rated Amps. the bundle is in spec. If the total bundle design Amps are greater than the Max, then you will need to change the gauge of however many wires it takes to bring the bundle into compliance.

You can add wires one at a time by entering a wire number in the box to the right, AFTER first" _

entering on the Main Electrical page the System Voltage and Allowed Voltage Drop in the first section, and all the required derating factors in the second section, such as temperature, # wires in bundle, altitude, and then clicking *Send to Bundle Analyzer* at the bottom right of the page. You can replace an individual wire # from the Main Electrical Page by selecting *Send value to specific wire # in Analyzer* and entering the wire # to replace in the box.

You can build your initial bundle by selecting *Send values to Sequential list #'s ...* and then entering your desired starting number in the box right of the selection button.

wire values sent to a specific wire # are highlighted in light blue to remind you so that you don't accidentally overwrite them if you later enter items sequentially.

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Sheet Metal Bending Calculations:

Click the metal type to Select your alloy type then click the list entry to select metal thickness, then click the *Get range* (can also use hotbutton select by *Alt+ R *) to get min-max radii.

Enter your desired radius, then enter your desired angle of bend then click *get setback* to get setback. To get metal allowance for bend, click *get bend allowance*.

Hydraulic Hose Bend Radius:

General Instructions --Hydraulic Hoses

Select the hose type *dash* number from appropriate list, then enter the desired operating pressure click *get radius* for minimum radius allowed.

To get the minimum radius in flexing applications, enter the desired number of degrees flex in the

appropriate box and click *get flex radius*

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Vacuum System Capacities and Line sizes:

Vacuum System calculations General Instructions.

Examine all vacuum driven components in system to determine which unit has the highest Vacuum requirement. Enter that requirement in the first block on the form * Enter vacuum...* then enter the Cubic feet per Minute flow rate requirements for each unit in the system in the set of blocks. Then enter the expect length in feet of tubing required to plumb the system Enter the number of 90 degree elbows expected in the system. If you have 45 deg. elbows, add 0.5 for each one. Select the tubing size from the list and CLick * Get Pump and CFM *. Your total requirements will be shown in the boxes on the right.

If 999 , or an improbably large number is displayed in the Vacuum requirements total, or a pop-up messge appears, you need a bigger tubing size. Entering CFM values that total more than 20 CFM will also creaate such results. This program will not calculate for CFM > 20, because the AC 43.13-1B does not provide data for values greater than that.

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Finding Tension on Wires and cables:

"This worksheet provides 2 ways to measure cable tension.

You can either measure at installation by measuring the force in in/lbs required to tighten the turnbuckcle or flying wire end or by measuring the cable deflecion and the force required to deflect the cable or wire.

TO MEASURE BY INCH/LBs. applied to turn the turnbuckle, enter the desired cable tension required in the so-labeled box, then the diameter of the thread end of the turnbuckle rod, and the threads per inch of the turnbuckle in the respective boxes.

Then click *find cable tension by force on turnbuckle*. the required force in inch/pounds will be displayed. The formulas assume a normal double-ended turnbuckle thread, or two-ended flying wire. If you are turning a long flying wire, apply the same displayed force to each end of the wire

TO MEASURE CABLE TENSION USING THE DEFLECTION METHOD, you must first construct 2 measurement tools . (construction drawings and usage diagrams can be displayed by clicking the *display.... button in the Instruction page for this worksheet:

1. a length of bar stock, longer than 1 foot, with a 1/2 inch high stand-off welded or screwed to each end, so that the distance between the stand-offs is exactly 1 foot. This is used to measure flexible stranded cable of most sizes and smaller diameter solid wires, up to 1/4 inch, and thinner flat flying wires of 10-32 or 1/4 inch threaded ends. Alternatively, as shown in the diagram, construct a bar of 26 inches in length with the stand-off at one end capable of sliding either to a 1 foot length or a 2 foot length. Heavy wires, such as bracing or "flying wires" must be measured over 2 feet.

2. A torque wrench adapter in the shape of a *U* with a socket on one side to connect to the torque wrench to apply the deflecting force to the wire. Use a scrap wrench socket and a flat steel bar about 3.5 inches long, 1 inch or so wide, and 1/2 or so thick. Drill 2 holes of 3/8 inch dia. in the bar 2.5 inches apart. Weld a length of 3/8 round rod or a bolt about 1.5 inch long into each hole. If using a bolt, ensure that the bolt head inner face is an inch or so out of the hole. Weld the socket to the top side of the bar exactly centered above one of the previously welded rods or bolts.

Now, put the leg of the *U* opposite the socket under the bar stock, and the other leg over the cable or wire, with the leg of the *U* with the socket over the cable at exactly the mid- point between the stand-offs on the bar. Then, apply pressure on the torque wrench until the cable deflects enough to JUST touch the measurement bar. Read the in/lb value on the wrench. Adjust the cable tension until the deflection torque is equal to the required value given by the worksheet software.

To measure tensions up to approx. 2000 or so lbs, such as found on flying wires of biplanes, using wires having threaded ends of 5/16 or 3/8 inch dia, prepare a length of bar stock slightly longer than 2 feet, and attach the 1/2 high stand-offs so that the distance between them is exactly 2 feet. SOLID WIRE AND FLAT FLYING WIRES with threaded ends of 5/16 and 3/8 inch dia. MUST BE MEASURED OVER 2 FEET.

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Saving files:

Click on the "file" menu at the top of the main menu page, and select the "save" option. Name and store the file in whatever directory you choose. There is a suggested folder in the AvmechaniCalc folder named "work files". Which contains sample worksheet files for your review and practise. You can store to this folder or make a new one of your choosing Each file uses the suffix ".AVM. It may be useful to save each file by naming them with the "N" number and date, or aircraft owner and date.

You must first select which open worksheets to save on the "Aircraft Info" page by checking the selection boxes for the desired worksheets. Only the worksheets selected will be saved. The aircraft and owner info will always be saved, it does not need to be selected. You can save all your aircraft/owner info in files and recall as required without re-entering data to prepare work orders and worksheets

Retrieving saved files:

You can retrieve any saved file by going to the "file" menu at the top of the main menu page and selecting the "open" option. Any worksheet that was previously saved into the file will be automatically opened, and the saved data entered into the worksheet cells—you don’t have to remember which worksheets you saved.

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Preparing FAA form 337:

Click the "Prepare FAA form 337" button on the main menu. A Data entry form will appear. Here you enter the usual aircraft, owner and conformity information as is done on a paper form. At the bottom of this page, click on the button to go to the 337 form item 8, which is the same as the back side of the paper form where you enter the description of the work accomplished. If you require more sheets to describe the work, just click at the bottom of the contuation description page(s) to add sheets. You can add up to 5 sheets.

Quick data entry: Aircraft, owner and mechanic/inspector data entry can be simplified a bit by clicking the button at the top left of the first data entry page. If you have filled out an Aircraft Info worksheet or opened one from a saved file, and it is now open, clicking that button will import the data on that sheet to the 337 form.

You can display the completed form for review by clicking the "Display 337 " button at the top of this page.

You can print the 337 form and all continuation pages by clicking the "Print 337 Form" button at the top right of the data entry page. You can also print the form through the File-print menu selection on the main menu page.

Completed 337 forms can of course be saved or retreived from disk through the usual file-save menu selection on the main menu page, after first selecting the option to save 337 form on the Aircraft Info worksheet.

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Viewing FAA Airworthiness Directives (AD):

You can view, download and save ADs for free. Click the main menu button "Get FAA Ads from FAA website" . A web browser will open automatically and connect you with the FAA AD index website. There, you can navigate thru the entire AD library by make or AD number and view the current bi-weekly list. Of course, you must be connected to the Internet for this to operate.

The FAA AD website comes up with their main AD page which alows you to review the AD lists either by make alphabeticaaly, or by numerically by AD number. The entire numerical and alphabetical indexes are available. You can also view the bi-weekly lists. We suggest that you download the Alpha and numerical indexes and save them thru the Acrobat reader. You can then quickly review the alpha index at any time to determine if there exists any prior AD s for the aircraft in question. Then, you will need only to view the bi-weekly lists to determine what has been added and if any new ones apply to the aircraft in question. Once you have the numbers of any pertinent AD s, you can then download or view them from the website. Fetching an AD by number is somewhat faster than by make.

If you have difficulty connecting, it may be because your internet connection is down Check that. If it appears that the FAA web address for AD notes has changed, the FAA home page will probably tell you so and list the new web address for AD s, Once you determine what the new web address for AD s is, you can change it in your AvmechaniCalc program so it will once again come up automatically.

The procedure to do this is this: Open "My Computer" or "Windows Explorer"; in the folder where the AvmechaniCalc program is stored, you will find a file named "FAA_URL.txt. Open it with notepad or wordpad and change the single line address. Make certain that the new address is enclosed in double quotes.

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General Formulas :

Click on Formulas and functions to see a few useful conversion formulas to use. Enter data as required and click buttons for answers.