My first lesson, which was earlier this month, essentially consisted of my instructor and I just going through the Diamond DA20-C1 Weight and Balance calculations due to bad weather. Although I had looked forward to flying for the first time again after my FAM flight, we ended up being grounded in Pitt Meadows and used that time to discuss some very important information.
So this is what the Weight and Balance sheet looks like for the DA20 – C1 at my school. Although this task seems slightly daunting at first, it becomes easier the more you do it! We fill out this sheet because pilots are responsible for the safe loading of their airplane as well as to ensure that it isn’t overloaded. Since the airplane’s performance is influenced by its weight, overloading it will cause significant problems. Additionally, the distribution of weight is also very important since the position of the centre of gravity affects the stability of the airplane. For this reason, the pilot must ensure that, while loading the aircraft, the C.G. is in the permissible range while also making sure that it remains this way during the flight.
For the sake of this blog post, I won’t go into great detail on ARM’s and MOMENT’s, but you’re more than welcome to ask a question in the comments below. If you take a look at the uppermost table on the Weight and Balance sheet, you’ll see that there are three important values to keep in mind:
- Zero Fuel Weight
- Take Off Weight
- Landing Weight
Zero Fuel Weight is literally just the sum of the Empty Weight of the plane (this can be found in the Aircraft Weight and Balance Report and is particular to a specific airplane), the Pilot and Passenger, Baggage, and Baggage Compartment Extension. As you can see, we had values for every single category except for the Baggage Compartment Extension. So now we know that the Zero Fuel Weight is 1,545.16 lbs.
The Take Off Weight is basically just the Zero Fuel Weight added to Fuel at Take Off, or the fuel on board at take off. In this case, fuel was nearly full at 120 lbs which gives us a Take Off Weight of 1,665.16 lbs.
The Landing Weight is essentially just the Take Off Weight minus the Fuel Required for your flight. In my case, we estimated that we would use approximately 5 Gallons of fuel for a one hour flight which is 30 lbs once converted. Thus, we ended up with a Landing Weight of 1,635.16 lbs.
Now that we’ve calculated all of these values, we have to also plot them on the Center of Gravity Moment Envelope for this particular aircraft. Keep in mind that we want all three of our values to fit inside the envelope; if even just one of our values lies outside of this envelope, we would need to make some changes to our weights before we go flying. To keep things simple, just know that if this was done right, the three dots should align in a straight, diagonal line (as seen on the Weight and Balance report). The first dot from the left represents the Zero Fuel Weight C.G., the second the Landing Weight C.G., and the third the Take Off Weight C.G. This graph illustrates how the Center of Gravity shifts while on your flight; if you take a second to think about this, it makes sense because as we’re flying, we’re also burning fuel which is directly related to the weight of the airplane. So you can clearly see that the more time we spend in the air, the more our C.G. shifts to the left within the envelope. As the Zero Fuel Weight C.G. is fairly close to the left edge of the envelope, we must keep in mind that the plane’s C.G. will have shifted dramatically from the moment we took off to the moment we’ll touch down (assuming that we’d be close to zero fuel on board as we land). Again, this is more of a concern for long cross country flights than it is for short one hour flights; however, it all comes down to the amount of fuel you’re carrying.
To sum it up, this is pretty much what I learned during that one hour of ground school because of bad Wx. I think it’s quite important to get a good grip on Weight and Balance reports as you’ll be doing one every single time prior to going flying. If you enjoyed the post, feel free to ‘Like’ and/or share! Thanks!