Solve Weight & Balance questions with the CX3 Flight Computer

In this video, we will show you how to solve Weight & Balance questions with the ASA CX3 Flight Computer. If you are studying for your Private Pilot certificate, this will save you time during the written exam!

We go over all the figures in the Testing Supplement and explain 4 of the main questions, with step by step explanation.

[SherwoodsCrafts]

At 27:43 in regards to Figure 61, I've found how to calculate it on the CX-3. It's similar to the problem you just did previously actually. First lets start with the written question and given answers:

(Refer to Figure 61 above.) If 50 pounds of weight is located at point X and 100 pounds at point Z, how much weight must be located at point Y to balance the plank?

A. 30 pounds
B. 50 pounds
C. 300 pounds

So, once again, it's a balancing act. Object Z has to have the same moment as the other 2 objects.
1) Set RF to "1"
2) Set weight to 100 pounds
3) Set arm to 100 inches

This gets you a moment of 10, 000. Now you need to make sure the other 2 balance out, and they already give you one.
4) Add item 2 and set weight to 50 pounds
5) Set arm to 50 inches.

This gives you a moment of 2500, so now you're solving for Y, which would look like this 2, 500 + (Y x 25) = 10, 000. Which would simplify to
Y x 25(arm) = 7, 500(moment).
6) Add item 3, and set the ARM to 25 inches
7) Set Moment to 7, 500

And your resulting Weight needed to balance the items is 300 pounds.

Thank You for your helpful videos. They are a life saver. I know this is a year late, but I hope you see this.

[kodblack]

Thank you so much for covering this! I'm taking the test soon and this has helped immensely.

[gobdeep]

After watching your video, I switched over to the CX-3 "Weight Shift Formula" option under W/B. The calculator option you presented is easier, in my opinion, but I wanted to see if I could make it work under Weight Shift Formula and I did. I've never used Weight Shift Formula before, so check my math.

Under Weight and Balance, continue as you did. Add your items and get your results. The results are Weight = 450 pounds, Moment = 8000 Inch Pounds, and Center of Gravity (CG) = 17.78.
Switch over to Weight Shift Formula and add your numbers = Item Weight for the "left side" is 500 pounds = enter that in Item Wt.
Total Weight from the original result is 450 pounds. Enter that in the Total Wt.
Center of Gravity (CG) from the original result is 17.78. Enter that in the CG box.
The CX-3 then outputs "Arm = 16.00 In" - so the answer is 16.

[jbrooks]

Wow, what an underrated video. 10/10 clarity.

[FlyingEagle]

The absolute best W&B video on YouTube!

[yepfishing]

Your videos are great. I just got this calculator and have watched two of your videos so far. At the same time I am very frustrated because I didn’t know about you before I signed up for Sportys private pilot course. It’s good and I learned a lot, however I feel like they left out a TON of information. They didn’t go over any of the calculations stuff, well if you consider just breezing past it and talking ruffly about it and not how to do it as going over it, then that’s what happened. I am doing all of their practice questions and not a single calculation question. I am not sure how in the world I would pass this test off this company’s program alone. I have been using YouTube to study for my test more then their stuff. Very frustrating. But again your videos are great. Thank you!!

[MRNO]

The way you explain man. Hats off for ya.
Thank you.

[RichardsonJanae]

Omg, I’m so glad I found this video!! I purchased another online flight school program that hasn’t been helping me much with explaining things like your video just did! I’m going to switch to your program! I can already tell I’ll be working smarter, not harder, following your advice and instructions!!!

[chenowthseater]

The way I solved question 61 using the CX3 is by entering the distances on the left side of the fulcrum as negative and to the right positive. All weights are positive.
So Item1 is X @ 50lbs at -50in. = -2500lb-in
Item 2 is Z @ 100lbs at 100in. = 10000lb-in
Now before entering item 3 Y, look at the current moment. It will be 7500lb-in. You need this to be zero to be balanced, so in item 3 enter -7500lb-in and -25in and Boom 300lbs will be calculated for Y.
As a double check look at the totals and the CG and Mom should be zero.
BTW, I did all of the balance questions this way and it work pretty good!

[ThatOnePilotZ]

SERIOUSLY! You are the best! PLEASE! keep them coming!

[raymondjolly]

One suggestion that I have for those who've already started doing cross country and are flying the C172 is make a personal copy of the Weight and Balance section of the POH and write down the ARMs next to the chart. I recommend this because the charts are not easy to read. For each line category, find where each line has an easy intersection to read and then calculate the ARM. By doing this, it will be much faster and easier to interpolate. I believe that Piper does this approach and I wish Cessna did this as well. For the 172S the ARMs are: PIlot and FP is 37.5, Fuel 46.7, Rear Pass. 73.3, Baggage 1= 100, Baggage 2 = 125. Constants are much easier to deal with.

[kodblack]

I know its a small amount but need the rest for my test fee. 😛 Thanks again!

[aviationmaster]

Amazing video! Keep 'em coming and I'll make sure to use the CX-3 once I take my PPL Exam!

[MRNO]

This Device is gonna be my New Best Friend.

[Justin-nydf]

Watching your videos because I ordered one, I am excited to not be using pen and pencil when I take my written.

[PAFOSFLY]

One of the most useful and easy to understand videos I've seen!!! Thank you!!!

[danbridges]

Great video. I know ads pay the bills but this is muuuuch.

[stephenstead]

Great video mate but that plank got me beat I did it with a Calculator I could not do it with the ASA-CX3 Thank you for this video mate nice one

[DetailFactor]

Hey there thank you for trying help us simplify weight shift formulas. Can you show another video on how to use the cx3 for this question please? (Refer to Figures 32 and 33.) Upon landing, the front passenger (180 pounds) departs the airplane. A rear passenger (204 pounds) moves to the front passenger position. What effect does this have on the CG if the airplane weighed 2, 690 pounds and the MOM/100 was 2, 260 just prior to the passenger
transter？it’s on my prepware and it’s driving me nuts. Also any update on fig. 61? Appreciate you

[gregsmith]

Never mind I got it. Thanks for the video