C of G charts/graphs

[67november]

was reading the CG section of the rotorcraft flying handbook yesterday, the use of the charts/graphs for equating the CG was interesting, just wondering if anyone uses them or do ya firgure it out the long way?

[flingwing206]

I use Excel spreadsheets and "cheat sheets" - for small aircraft you can just make a chart of cabin weight, max. weight difference between pilot and passenger, and allowable fuel at cabin weight. For instance, the 300C/CB/CBi will not go out of forward CG if you can carry 10 gallons of fuel while remaining inside MGW and cabin load limits.

[Guest pokey]

i do it the old fashioned way, add the weights/ moments,,do the most extreme loading conditions, fore/aft & if it all adds up? then good to go ! (altho the 300 that i fly is not like a 747 or some big cargo plane that requires CG calculations b4 every flight)

[Wally]

The AS350/355 "slide" chart works very well, and quickly. Unfortunately, it's not very precise, so when it's questionable, I use a calculater with 2 memories. There's only a few stations that vary- front seat row, aft seats, side holds, aft hold, fuel (tanks), and occasional cabin cargo, so it's pretty quick. Even quicker if you update a running total weight and moment, every flight- Twinstar requires computed cg as well as allowable range at T/O weight. Calculator's quicker than a spreadsheet app.

[Eric Hunt]

"Calculator's quicker than a spreadsheet app." says Wally.

 

How can this be so? You take out your piece of paper, write down the fuel weight, weight of each passenger and the seat they are in, weight of baggage and the hold it is in, take out calculator, punch in numbers, do multiplications, write the numbers onto the paper, blah blah... Writing is slower than typing.

 

Spreadsheet: click to open, click applicable seat, type pax name, tab, type weight, tab to baggage hold, type weight, tab to fuel, type weight (or litres or gallons), look at answer. Click to print the loadsheet, manifest, and graph of CG movement.

 

And they are so easy to construct.