While you’re Downloading the calculator now, read about it’s features and limitations. Internet Explorer users: after downloading the file, change the extension to .xlsx or .xls.
This is the B3 release of the R22 Quick Weight and Balance calculator. Thanks to those who commented to me off-line that the unlock was a pain in the ass. This version removes the unlock, and moves the BEW and arm data to the front page where it can be locked. (By the way, don’t be afraid to post your criticism directly on this page!)
Do you run a weight and balance before every flight? Or do you just guesstimate how much fuel you can carry and assume you’ll be close enough to being in CG? I know guys who don’t do a W&B except for check rides. Not good enough for me. Limitations are limitations, and early in my training I developed worksheets for each helicopter so that I had the baseline CG values for every flight. From there it was easy to add a weather check, and HIGE/HOGE calculations into my pre-flight routine.
Now, there are plenty of these already out there. Maybe your flight school has one. I put some real thought into this though to make it user-friendly and packed with features. On the first page, fill in the green boxes with the basic empty weight and arm data for the helicopter with all equipment installed. You can then password-protect the worksheet so nobody can inadvertently alter those values. Next, enter all the variable data into the green boxes on the Conditions worksheet: pilot and passenger weight, baggage weight, optional equipment (default is installed), and fuel. After the passengers and baggage weights are entered, the Calculator displays the maximum allowable fuel weight (which may be greater than the fuel capacity). The CG graph is updated automatically with the take-off (solid green) and zero-fuel (open white) conditions. Endurance is based on a an editable burn rate (usually 8-10 gph). This is a quick and clean way for students to see how CoG shifts and changes during flight. This sheet is locked so that no formulas are inadvertantly altered.
I thought about hiding the Calculations sheet altogether, but as a learning tool it’s great. Your students can complete calculations by hand and then check their calculations there. For a beta version, this is also a good troubleshooting tool.
The student worksheet is meant to be used day-to-day for manual calculations. The graphs, arms, weights, capacities, and limitations are reproduced from my POH, but you must confirm that they are consistent with your aircraft’s POH. All cells are unlocked and the sheet is unprotected so you can enter the data for your aircraft. The rest of it is simply an intuitive template for doing W&B calculations and gathering pre-flight data. It should also print out very nicely.
A few disclaimers. I have tried it with several helicopters and it works fine. They are all Beta IIs though. I also run Windows Vista and Microsoft Office 2007, so I have no idea how the Calculator will work with your system. I do know–and this one’s important kiddies–that you must enable active content and macros. Office 2007 automatically disables these features unless you tell it to enable them.
I’d like to see some ideas for practice problems that force students to develop a working knowledge of CG. The calculations themselves are only tedious, but applying them to real-world scenarios is what I’d like to get at. In the screen shot, for example, I have to take 240-lb Bubba on a 1.25-hour flight. Can I do it without him having to leave his boots behind?
Anyway, you can download the Quick Weight and Balance Calculator Beta right here. If you have any comments, please post them below.
I DL’ed the weight and balance calculator for the R22 zip file opened it up and don’t have a clue on how to get the calculator to work in exel….I don’t see an execute file am I missing something?
Hi Jeff,
Sorry you’re having problems. The file should download ready-to-use as an MS Excel file (.xls or .xlsm). Although I haven’t tried it, the calculator should work in versions of MS Excel up to 2007. I’ll send the calculator as an attachment directly to you so you can try again. Since the calculator uses macros for the charting functions, you do need to enable active content once you get it open for it to work properly. MS Excel will usually ask you if you want to do this, or it will tell you that Active Content has been disabled.
I tried it with Office 2008 for Mac. The optional equipment buttons and doors buttons don’t work. Everything else seems to work fine. Any chance of a Mac version?
Sorry, I don’t know anything about Macs except that my wife’s mouse only has one button. How you do anything with that I can’t imagine.
I have had no luck in getting it to work in excel. Any suggestions?
Hi Luke,
Can you tell me what version of Excel you’re running? I’ve tested the calculators in MS Office 2007, but not in earlier versions. For any version, Excel will automatically disable the macros that are behind the graphing functions, so you’ll have to tell it to “Enable Active Content” or “Allow Macros”. In 2007, allowing active content is easy–there will be a yellow bar at the top of the screen (usually just below the formula bar) that will tell you that the macros have been disabled. Click that and the click “Allow” or “Enable”, and you should be rolling.
If you’re trying this on a Mac, I don’t think it’ll work at all for you. I tried the R44 calculator on my wife’s Mac and most of the functions didn’t work properly.
Please let me know if you get it working or not…I’ve had several users report problems but not follow through with troubleshooting. Just makes it harder for me to help others like yourself!
I am running excel 2007. The issue that I am having is that after I download it I can not find any file that will open in excel. I have attempted to open every file in downloaded folder.
The file you’re looking for has a .xlsm extension, and should open right up with Excel 2007.
Thanks to Rich…he figured out that IE appends the Excel file with the .zip extension. This has caused a lot of grief for guys who downloaded the file and weren’t able to open it afterward. If you downloaded the calculator with IE, just change the file extension from .zip to .xlsx (for Excel 2007) or .xls (for earlier versions), and you should be good to go.
Hi there. I am loving your W&B for the R-22. I have a question about the aux fuel computation. Am I wrong that the math of 10.2 (times 6 lbs a gallon) is 63 not 83? (under calculations, 2nd sheet)?
Doh! Yes, you are correct. When I get back home I’ll correct that typo and update to V4. Fortunately the calculations are still correct, and this error primarily affects the data portion of the student worksheet.
Thanks for your help–it’s this kind of collaboration I’m counting on.
When I get smarter …I hope to help with something more significant. I really enjoy your site. Nice going…you are the type of person who would make a great cfi.
Hi Chris and thanks for your effort. I know it’s tough to build these spreadsheets (I’ve tried!).
I use OpenOffice on Linux, and while some of the calculations work… the in/out of CG graphics are not working, and the HIGE/HOGE calculations show no result.
I commend you for your effort. I’d be willing to contribute a donation to a free (FOSS) version that works… You have my email and my appreciation for your effort.
I only have 158 hours… but working on my Commercial in a 22 🙂
Cheers
E
Thanks Ehud. Excel is sensitive to the platform, so the automatic plotting for CG isn’t going to work on anything but a PC (I’ve tried it for mobile Excel apps…no dice), but there isn’t a HIGE/HOGE calculator. An open office version would be awesome for those who are interested in it. I can add it to the downloads page and credit you.
Best of luck on the commercial!
I’m impressed. I get sooo sick of going through weight and balance every time on paper. This is amazing and I checked accuracy and it seems to be right on the money. Of course I’m not using this as the sole weight and balance because I’m sure it’s not FAA approved but nonetheless it is a great tool and will be great for my future students. Thanks Chris!!!