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Bruce Leehan

Help with loading / CG% -until the load editor comes

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If you need the load editor because you are over loading the jet, this is meant for you. However, if you're just wanting the load editor because you paid for it...this is not for you. As a Loadmaster on C-130's for several years, I learned that sometimes just because you are handed a "validated" loadplan, it may not suit the fuel load your pilots need to get where they are going or...the loadplanner was obviously smokin 'crack'. LOL Here are a few simple rules of thumb for a technique called Pyramid-Loading, that you can use on the PSS 757 cargo/PAX versions.1. Load the airplane with the heaviest item in the wingbox section of the jet(this is where the CG% is located, as the jet will move around it's axis.)2. Continue loading the next heaviest items in the center on either side of the first item then work your way to both ends of the airplane, in this fashion. KEEP THE LOADS IN FRONT AND BEHIND THE WING AS EVEN AS POSSIBLE OR YOU WIL BE NOSE HEAVY OR TAIL HEAVY. (The reason it's called Pyramid Loading is that if you looked at a weight diagram, the heavist loads would be in the wingbox(center) of the airplane, and they would get progressively lighter as the load are placed toward the nose and the tail.) This is what keeps the Center of Gravity or CG% in limits. i.e. CG window [24%-25%-26%] +Tail--------------------------Wing-Area-------------------------Nose>LBS.- 4500 5000 5000 6000 6900 10000 7500 6000 6000 4200 40003. Once you have the load onboard that you want/need, add the total load weight with the basic/empty weight of the airplane (no fuel just airplane) this total is called Zero Fuel Weight 4. Figure out a rough estimate of how much fuel you will burn per hour and how far to your destination. (I use a wag at 8500 lbs. per hour fuel burn and it works fine for me) ie. From A to B is 4 hours 30 min = 4.5 X 8500 = 38250lbs of fuel required for the trip. Now add an extra 1 hour for taxi, climbout, etc. and round up to nearest 1000. TOTAL= 40000.5. Add Required fuel to Zero Fuel Weight and then you have Gross Weight for Takeoff. Make sure that this weight does not exceed the limits for takeoff based on the perf data. (you can find this on the internet)For landing weight- subtract Req Fuel wt (without the extra) from the Gross weight for takeoff. ie (TOT Take-off) - 38250 = LNG WT (the CG% will move forward a little bit as you burn fuel)As long as you just load the fuel you need you are pretty close. Again, this is only meant for folks who don't know about such things and it is DEFINITELY NOT FOR REAL-WORLD USE. For one, FS doesn't simulate Fuel Dumping in emergencies. **You may be in limits for takeoff but if you are heavy, you may not be in limits for landing weight with all that fuel still on-board.** I am sorry this is long winded and I hope it encourages others to research about airplane weight and balance. It has been a fun job for me. Take care, keep the shiny side up!Bruce Leehan, USA

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