B-29 SUPERFORTRESS WEIGHT AND BALANCE

foreign the distribution of weight that determines balance the athlete attains balance through trial and error but the v-29 attains it through a scientific weighing and an accurate computation of its basic weight and index but before the airplane can be weighed it's necessary to know where the weight is the distribution of weight that matters after the fuel tanks have been drained and the oil tanks filled each item of equipment must be carefully inventoried throughout the airplane chart a provides an inventory list to check by a check mark in the in Airplane column indicates that the equipment is in the airplane any item not on the airplane is marked with a zero the removal of an item should have been entered on chart C with the necessary weight computations if it is no further checking of the item on chart a as necessary all liquid containers must be full that goes for water containers and thermos bottles and all smaller tanks in the airplane such as the hydraulic fluid tank and the anti-icer tank if it's installed all of them must be full including the gas tank for the Putt-Putt weighing involves other preparations too since the weighing is done electrically the electric Wing kit must be plugged into an external source of 24 volts DC power if a battery cart isn't available the airplane's 24 volt system will do but no matter what source of power you use the kit must be attached at least 10 minutes before it's used so it can warm up to check the power source you press the battery switch if the meter needle is in the yellow section it indicates the terminals are reversed that's easy to fix though by reversing the terminal leads now the needles where it belongs on the left the power source is okay so while the kit warms up other things can be taken care of when the plane's brakes are released and the chalks placed at the wheels the airplane can be prepared for jacking first it'll be necessary to deflate and lock all three oleos loosening the filler plug near the top of the audio strut just a little allows the air to escape slowly and permits the strut to come down the main gear oleos are deflated at the same time to prevent the struts from binding after the struts are deflated the torsion locks are attached to each landing gear they'll keep the struts from extending when the airplane is jacked the locks go on snugly and they're bolted securely when the oleos struts are taken care of the Jacks can be moved into place and centered under the airplane's jacking cones in this way each Jack can be placed very near its final position and they can be extended but leave enough space under the jacking pads for the cells before the airplane can be jacked it's necessary to attach the cells to the electric cables when you connect the cells don't let the nut on the Cannon plug do all the pulling push the plug in as you turn the nut when the cells are firmly attached to the cables they can be zeroed the initial load selector is set at zero and then the weight dial is turned to zero these cells have colored Stripes painted on them which correspond in color with the red yellow and blue zero set knobs on the panel the sales selector set at number one position the red cell is checked the cell balance switch operated cell needle observed it's okay now for number two the yellow one cell selector set at two balance switch press the number two is off so it's zeroed by turning the yellow knob in the direction the needle should go now number two is ready number three the blue one is next it needs adjustment too so the Blue Knob is turned until the needle is zeroed when all three cells are zeroed they're ready to be installed on the jacks but they require adapters the plug type for these particular jacks with adapters attached the cells can go on the Jacks the red cell and the nose Jack the yellow one number two on the left wing Jack and the blue one number three on the right wing Jack it's important that the cells be centered properly on the Jacks and under the airplane's jacking pads if they aren't there's a danger of the airplane slipping off the Jacks and a chance of the weight not being properly distributed check each cell carefully after it is installed on the jack for accurate weight readings you can't be too careful every part of the jacking procedure is a job that calls for precision the Jacks themselves should get a careful check a check that includes the bleed valve on the Jack's hydraulic mechanism these three big hydraulic jacks must have a good going over because they Bear all the way to the airplane in addition to the big Jacks two small strut Jacks are used one under each main gear jacking pad they're a must for safety and the most for accuracy is clearing the airplane of all equipment not included in its basic weight and having the weight officer check charts A and C after the inventory another thing drafts do affect the weighing so close all Hangar doors and turn off Heating and ventilating systems the cells get another zero check after they're on the Jacks and just before they take up the weight of the airplane when the cells are checked and the charts found to be in order the airplane is then ready to be leveled this particular B-29 uses the plumb bob and a graduated scale instead of the old type level and level bars the graduated scale is a station 365. it's protected by a felt line cover but don't forget that cover goes back on for earlier b-29s authorized changes will permit the use of the Plumb bomb it simplifies the entire leveling process the cord is attached to a hook at station 365. when everything's set you're ready to start jacking you will leave a man near the Bombay where he can see the men at the jacks the nose the left main the right Mane and the tail safety Jack bring up all Jack slowly and smoothly but always with the wing Jacks a little ahead of the nose Jack the wheels of these particular Jacks retract so the Jacks have a firm base as they lift the airplane off the ground to keep the big Jacks from ramming into the wings if the cell should slip have the smaller Jacks under the main gear brought up at the same time that goes for the tail Jack too always about a half inch from the jacking pad keep an eye on the cells as the plane goes up it shouldn't go up very high just enough to clear the ground and when it does it's time to check the airplane's attitude to see what leveling is necessary the Bob is to the left of the center line that means the left wing is a little too low it may seem like a lot of work getting a B-29 perfectly level and in a way it is but if the leveling isn't accurate you may as well forget the whole business hold it louder latitude's okay it's still off longitudinally so the nose will have to come up with the nose Jack raised a little the plane should be just about level with a plumb bob directly over the zero graduation it is level now the distribution of the weight on the cells is even the way it must be for an accurate reading so everything's set to see what the plane waves for the weight of the nose the cell selector is turned to cell number one the initial load switch to the 10 000 pound Mark the cell balance switch press and the weight dial turned until the needle swings back to zero when it zeros the weight will be recorded in the weight dial 1650 that's added to ten thousand for a no scale reading of eleven thousand six fifty the left wing weight is next and that is obtained from number two cell the cell selector goes to number two and the load switch to the 30 000 pound mark the cell switch goes down and the weight dial turned until the needle zeros recorded weight 1995 that is added to thirty thousand and recorded a scale reading for the left main for a total of thirty one thousand nine ninety five the sell selector to number three the load switch at 30 cell switch pressed and the weight dial turn until the needle is at zero right wing weight 1485 that is added to thirty thousand and recorded in the weighing form like the other weights and then the scale readings are totaled those torsion locks are a help in both jacking and lowering the airplane but they weigh 12 pounds each so their weight must be in it for deduction in the tear column since the airplane will now have them when it takes off the lock weights are the only weights that can be deducted as tear in electric wing the airplane can be lowered now and checked for other weight variations when the airplane is lowered the pressure has to be released from the Jacks carefully so the plane will come down slowly and evenly remember Jack could only three points the plane is still in delicate balance and any sudden movement might upset that balance and cause a lot of grief when the Jacks have been Lord so the cells are not touching the jacking pads and while they're still on the Jacks they should be checked again to see if their zeroing has changed during the weighing process conditions this time must be the same as when the cells were first zeroed both the initial load selector and the weight dial must be at zero when they are press the cell balance switch if the needle isn't at zero the weight dial must be turned until it is and here's a minus 50 pounds in the number one cell the nose cell split that in half reading 25 pounds that is added to the no scale reading after deducting the 12 pounds tear and the total then listed in the net weight column foyer plus reading on the weight dial you split the difference and subtract it from the scale reading be sure to check each cell number two okay and so is number three the needle is at zero the electric kit will give you the weights and the weight variations and that's about all the rest of the weighing process is simply arithmetic but the figures the kit gives you are accurate and to make sure it will always give accurate readings take care of it get the cable to the battery cart has been kept off the floor it'll be clean enough to Stone the kit as it is if it hasn't been wipe it with a clean dry cloth and those cells they're delicate sensitive instruments dust and dirt in them are as bad as lighted dynamites each cell must get a light coating of oil and then be cleaned with a dry cloth after they're all taken care of their dust caps go on and they're stowed properly in the kit the cell cables will always be on the floor so they also are wiped with a clean cloth when the equipment is taken care of store the kit in the dry room the same temperature as the hanger it will be used in it takes a lot of work to weigh a B-29 for three weight readings the for the weight officer getting those weight readings isn't the end of the work in a way it's just the beginning well they're used to get the plane's basic center of gravity but to get that we need a couple more figures we need the arms for the wing and those jacking points knowing the weight at these points we can compute their moments the arm is the distance from the reference datum line to the jacking points Wing 481 and 3 10 inches nose 151 inches these two figures are entered on the wing form in squares E and F the eight square is for the basic arm of the airplane but to get that we need the moments now of the other two arms and weights they're obtained by simply multiplying the arm times the weight that is the moment of the two Wing weights is the sum of the wing weights times their arm of 481.3 the moment of the nose is the nose weight times the arm of 151 inches the moments of course are always in inch pounds the nose and Wing moments are total for the airplane's net moment to obtain the average arm divide the airplane's moment by its net weight the average arm is the center of gravity in inches it goes in the eighth Square it is then transferred to the back side of the wing form with the net weight and moment figures the airplane was weighed with full oil tanks as it should be sold those 340 gallons 1275 pounds in each tank will have to be accounted for their arms are given on the miscellaneous data page 402 and 378 inches they are recorded on the weighing record as listed their moments are the result of the arms times the weights of the oil the moments and weight of the oil are now subtracted from the airplane's net weight and moment nothing goes in column one or two because all non-basic equipment was removed from the airplane before weighing we now need the basic arm and like the average arm it's obtained by dividing the basic Moment by the basic weight the only figure lacking now is the basic index and there's a formula for finding it inscribed on the load adjuster under the slide the index figure is not the center of gravity of the airplane it is the basic arm computed as basic index for load computations the basic arm we found to be 431 and 4 10 inches that is subtracted from 445.5 the basic weight for this airplane is 72 569 pounds which is multiplied by 14.1 the result then divided by twenty five thousand and the quotient subtracted from 110 the index in this case is 69.1 it is posted on the weighing record under remarks can be noted that the airplane was weighed with the electric weighing kit at stations 481.3 and 151. the computed weight moment and index are posted on chart C the index is the last figure entered on the wing record and the last figure posted on chart C it was for this figure that the airplane was weighed for upon this figure all subsequent loadings of the airplane will be based the flight engineer uses this index as his starting point for loading the airplane the hairline of the indicator crosses 69.1 the basic index and the oil is loaded 340 gallons the new index which includes the oil weight is ended on the oil line in the index column the way to the crew members and their baggage and cargo are recorded next like all the other weights they are loaded by compartments on the back of the adjuster these compartments are diagrammed and labeled for crew loading the zero indicator line of the compartment scale is centered under the hairline of the indicator the indicator is then moved along compartment a line to the 200 pound mark the new index is recorded and the weight for each compartment is computed in this way until the minimum landing gross weight and index are accounted for then Expendable items are loaded ammunition first the zero line for the compartment scale is used and the ammunition loaded by compartment the weight of ammunition for each compartment is loaded and recorded and then the bombs are loaded the bomb loading scales are on the Left End of the slide forward bomb loading on the top scale the rear bomb loading on the bottom scale five thousand pounds of bombs in each Bay fuel loading is next 5 000 gallons in the remarks column the breakdown is listed 2500 gallons in both inboard and outboard tanks the fuel scale is in the center of the slide 2500 gallons are loaded in the upper fuel line for the inboard tanks and 2500 on the lower line for the outboard tanks the last index which includes the fuel weight is also posted as index for takeoff condition uncorrected the Bombardier moves from compartment a to c and the tail Gunner from L to H so that weight change must be accounted for the index changes slightly but this time the actual change is recorded a plus 1 and 1 10 for Bombardier change and a minus two and six tenths for the tailgunner the net difference is recorded on the net difference line and then subtracted from the index for takeoff condition uncorrected the final index must be computed as center of gravity in percent of the Mac Slide the scale back and find the airplane's gross weight the center of gravity is where the hairline and the gross weight line intersect for the gross weight of this airplane loading approximately 28 and seven tenths percent while within the permissible limits signatures of the pilot and the approving officer later finish her up but there's one thing to remember about the form F its accuracy goes beyond the man who computed the loadings it goes back to the men who checked the charts and weighed the airplane and computed the basic weight and index [Music] determining the basic weight and balance of a v-29 is something like winning a war many men do many jobs and they do them well [Music] men are responsible to themselves and to the men they work with each man of the flight crew is responsible to see to it that nothing is brought into the loaded airplane taken from it or moved from one compartment to another before takeoff unless load computations are revised accordingly all along the line responsibility and accuracy for the lives of men are in balance [Music]