It works really well once you figure out a few things
A few notes for those who may come across this app and consider using it. Make certain you know if your POH references the ‘arm’ or ‘moment’ with the weight. I think it is fairly common in the US, for example for weight and moment to be provided and not weight and arm, to include the CG envelope. I thought I had all the info entered correctly but realized that I have put in ‘moment’ info when the app was asking for ‘arm’ instead. So I had to calculate the arm for all the inputs. Once I got it enters correctly, it ALMOST worked perfectly. This brings me to the second ‘gotcha’. I entered Basic weight info, to include the arm for the plane itself. There is also a ‘station’ for basic weight. So if you enter the basic weight for the plane itself, make certain you enter a ‘zero’ for the station info at the aircraft data entry page (where you enter your data for the calculation itself. I ended up have the basic weight entered twice putting me way outside the envelope!
The only other request I have is for there to be a way to print out the calculations themselves. It is a good thing to show the calculations if you go to a flight review or for an instructor.
Easy to Use
W&B
Displays CG envelope wrong
Response from developer
Hi. I can assure you, WB Calc is perfectly safe to use. Center of Gravity is the point at which an airplane would balance if suspended. This is represented as a DISTANCE (or index) from a Reference Datum. Your POH gives you the airplane CG LIMITS (the envelope) in weights and distances from this Reference Datum. You will usually find this data in the Limitations or Weight and Balance chapter. WB Calc uses this basic formula: weight x arm = moment. Total moment divided by the total weight equals aircraft CG. This is checked against the aircraft CG and weights limitations from your POH. This is then plotted on the CG limits envelope. And NOT against any “weight vs moment” envelope. Another method of calculation, is to use of convenience graphs provided by the manufacturers. To simplify and reduce the number of steps in the calculation, arms and CG is omitted, and moments are sometimes divided by 100. Here is where you will check the sum of moment and total weight against the “weight vs moment envelope”. WB Calc does not support these kind of convenience methods of calculating aircraft CG. Have a look at this website. It shows several different methods of calculating aircraft CG: https://www.flightliteracy.com/determining-loaded-weight-and-cg/ Fly Safe! Best Regards Antun Pejakovic
Not worth .99
Response from developer
Hi. Sorry to hear you are disappointed with WB Calc. The app is designed for easily calculating weight and balance on light GA aircrafts. It is not meant to be a complete flight planning or EFB package. If there is some functionality or features you feel are missing, please let us know and we will be happy to look into it. Regarding kg showing instead if lbs... Did you perhaps not set lbs as input unit in the station settings? There is a tutorial showing how to configure an aircraft correctly on our facebook pages. www.facebook.com/WBCalc/ Step 4 shows how to select desired input unit. Fly safe!
