Appendix 3
9,000 10,000 11,000 12,000 13,000 14,000 15,000 16,000 17,000 18,000 272 276 280 284 288 292 296 300 304 Fuselage Station (Inches Aft of Datum) Weight (LBS) Max Ramp Weight Max Landing Weight Max Zero Fuel Weight Curtailment for Variations to Passenger Weight Curtailment for Fuel Burn Off Curtailment for Variations to Passenger Seating
FIGURE 3-5. OPERATIONAL LOADING ENVELOPE WITH A CURTAILMENT FOR
VARIATIONS IN PASSENGER SEATING
b. To expand the operational loading envelope, an operator could choose to use the actual seating location of passengers in the cabin and reduce the curtailment for variations in passenger seating. Figure 3-6 below shows the expansion of the operational loading envelope.
Appendix 3
9,000 10,000 11,000 12,000 13,000 14,000 15,000 16,000 17,000 18,000 272 276 280 284 288 292 296 300 304 Fuselage Station (Inches Aft of Datum) Weight (LBS) Max Ramp Weight Max Landing Weight Max Zero Fuel Weight Curtailment for Variations to Passenger Weight Curtailment for Fuel Burn Off
FIGURE 3-6. OPERATIONAL LOADING ENVELOPE USING ACTUAL SEATING
LOCATION OF PASSENGERS
Page 11 (and 12)
6/10/05 DRAFT AC 120-27E Appendix 4 APPENDIX 4. ADDITIONAL CURTAILMENT TO CG ENVELOPES FOR
PASSENGER WEIGHT VARIATIONS IN SMALL CABIN AIRCRAFT
a. The use of average weights for small cabin aircraft requires consideration of an additional curtailment to the center of gravity (CG) envelope for passenger weight variations and male/female passenger ratio. This curtailment is in addition to the standard curtailments discussed in Chapter 1 with examples in Appendix 3.
(1) Passenger weight variation is determined by multiplying the standard deviation (from the source of the average passenger weight used) by the row factor from Table 4-1. The following table is a statistical measure that ensures a 95-percent confidence level of passenger weight variation, using the window-aisle-remaining seating method.
TABLE 4-1. ROW FACTOR No. of Rows 2-abreast 3-abreast 4-abreast 2 2.96 2.73 2.63 3 2.41 2.31 2.26 4 2.15 2.09 2.06 5 2.00 1.95 1.93 6 1.89 1.86 1.84 7 1.81 1.79 1.77 8 1.75 1.73 1.69 9 1.70 1.68 1.65 10 1.66 1.65 1.62 11 1.63 1.59 1.59 12 1.60 1.57 1.57 13 1.57 1.54 1.54 14 1.55 1.52 1.52 15 1.53 1.51 1.51 16 1.49 1.49 1.49 17 1.48 1.48 1.48 18 1.46 1.46 1.46
(2) Protect against the possibility of an all-male flight by subtracting the difference between the male and average passenger weight.
(3) The sum of these two provides an additional weight to be used for CG curtailment, similar to the way in which passenger seating variation is calculated.
b. Calculation of the curtailment passenger weight variation is decided by multiplying the standard deviation by the correction factor and adding the difference between the average allmale and average passenger weight. For example, assuming a 47-pound standard deviation, the difference between the average all-male and average passenger weight is 10 pounds (from 1999–2000 National Health and Nutrition Examination Survey (NHANES) data), and a sample aircraft with 9 rows in a 2-abreast configuration. The additional weight to be curtailed is determined as:
Appendix 4 Weight for Additional Curtailment = (47 × 1.70) + (10) = 90 lb
c. For the example, the additional curtailment should be accomplished by assuming passenger loading at 90 pounds using the program method for passenger seating variation (e.g., window-aisle-remaining). Using the window-aisle-remaining method, the additional curtailment in the example is determined to be 59,031 inch-pounds forward and aft. Table 4-2 displays the calculations used in this example.
TABLE 4-2. SAMPLE CURTAILMENT DUE TO VARIATIONS IN PASSENGER
WEIGHT AND MALE/FEMALE RATIO USING WINDOW-AISLE METHOD Passenger Weight: 90 Coach Class (Y) Cabin Centroid: 323.8 Forward Seating Aft Seating Seat Seat Total Total Moment Seat Seat Total Total Moment Row Centroid Moment Weight Moment Deviation Row Centroid Moment Weight Moment Deviation 1 198.0 17,820 90 17,820 -11,321 9 436.0 39,240 90 39,240 10,099 1 198.0 17,820 180 35,640 -22,642 9 436.0 39,240 180 78,480 20,198 2 228.0 20,520 270 56,160 -31,263 9 436.0 39,240 270 117,720 30,297 2 228.0 20,520 360 76,680 -39,884 8 407.0 36,630 360 154,350 37,786 3 258.0 23,220 450 99,900 -45,805 8 407.0 36,630 450 190,980 45,275 3 258.0 23,220 540 123,120 -51,726 7 377.0 33,930 540 224,910 50,064 4 289.0 26,010 630 149,130 -54,857 7 377.0 33,930 630 258,840 54,853 4 289.0 26,010 720 175,140 -57,988 6 347.0 31,230 720 290,070 56,942 5 318.0 28,620 810 203,760 -58,509 6 347.0 31,230 810 321,300 59,031 5 318.0 28,620 900 232,380 -59,031 5 318.0 28,620 900 349,920 58,509 6 347.0 31,230 990 263,610 -56,942 5 318.0 28,620 990 378,540 57,988 6 347.0 31,230 1,080 294,840 -54,853 4 289.0 26,010 1,080 404,550 54,857 7 377.0 33,930 1,170 328,770 -50,064 4 289.0 26,010 1,170 430,560 51,726 7 377.0 33,930 1,260 362,700 -45,275 3 258.0 23,220 1,260 453,780 45,805 8 407.0 36,630 1,350 399,330 -37,786 3 258.0 23,220 1,350 477,000 39,884 8 407.0 36,630 1,440 435,960 -30,297 2 228.0 20,520 1,440 497,520 31,263 9 436.0 39,240 1,530 475,200 -20,198 2 228.0 20,520 1,530 518,040 22,642 9 436.0 39,240 1,620 514,440 -10,099 1 198.0 17,820 1,620 535,860 11,321 9 436.0 39,240 1,710 553,680 0 1 198.0 17,820 1,710 553,680 0 NOTE: The following definitions describe the parameters used in the samples in Tables 4-2 and 4-3:
• Seat Centroid: Location of passenger weight at seat
• Seat Moment: Additional passenger weight × seat centroid
• Total Weight: Sum of additional passenger weights (running total)
• Total Moment: Sum of additional passenger moments
• Moment Deviation: Difference between total moment and moment generated by assuming additional passenger weight is located at the cabin centroid (323.8 in)
Appendix 4
d. If the operator chooses to use the passenger cabin zone concept (as described in Appendix 3) and apply this concept to account for variation in passenger weight, then the row factor in Table 4-1 corresponding to the number of rows in each zone should be used.
(1) Considering three cabin zones with each zone containing three rows in a 2-abreast configuration, the required row factor (see Table 4-1) is 2.41. The row factor is multiplied by the standard deviation and the difference between average all-male and average passenger weights is added to provide the additional weight consideration. In our example, the standard deviation is calculated from the National Health and Nutrition Examination Survey (NHANES) data as 47 pounds, and the difference between average all-male and average passenger weights is 10 pounds. The resulting additional weight for curtailment is 47 × 2.41 + 10 = 123 pounds. This additional weight is applied per the window-aisle-remaining concept for each cabin zone independently and the results are summed to determine the amount of curtailment. In this case, the curtailment is found to be 23,791 inch-pounds forward and aft.
(2) If an operator chooses to use row count, the operator must use the row factor for two rows. In this example the required row factor is 2.96 (see Table 4-1). The row factor is multiplied by the standard deviation and the difference between average all-male and average passenger weight is added to provide the additional weight consideration. In our example, the standard deviation is calculated from the NHANES data as 47 pounds, and the difference between average all-male and average passenger weights is 10 pounds. The resulting additional weight for curtailment is 47 × 2.96 + 10 = 149 pounds. This additional weight is applied as if a two-row passenger zone concept is used for passenger seating. The resulting curtailment is determined to be 17,880 inch-pounds forward and aft (see Table 4-3).
Appendix 4 TABLE 4-3. SAMPLE CURTAILMENT DUE TO VARIATIONS IN PASSENGER
WEIGHT AND MALE/FEMALE RATIO USING ROW COUNT METHOD
Coach Class (Y) Cabin Centroid (Rows 1-2): 213.0Coach Class (Y) Cabin Centroid (Rows 3-4): 273.5 Coach Class (Y) Cabin Centroid (Rows 5-6): 332.5 Coach Class (Y) Cabin Centroid (Rows 7-8): 392.0 Passenger Weight: 149 Coach Class (Y) Cabin Centroid (Row 9): 436.0 Forward Seating Aft Seating Seat Seat Total Total Moment Seat Seat Total Total Moment Row Centroid Moment Weight Moment Deviation Row Centroid Moment Weight Moment Deviation 1 198.0 29,502 149 29,502 -2,235 9 436.0 64,964 149 64,964 0 1 198.0 29,502 298 59,004 -4,470 9 436.0 64,964 298 129,928 0 2 228.0 33,972 447 92,976 -2,235 9 436.0 64,964 447 194,892 0 2 228.0 33,972 596 126,948 0 8 407.0 60,643 149 60,643 2,235 3 258.0 38,442 149 38,442 -2,310 8 407.0 60,643 298 121,286 4,470 3 258.0 38,442 298 76,884 -4,619 7 377.0 56,173 447 177,459 2,235 4 289.0 43,061 447 119,945 -2,310 7 377.0 56,173 596 233,632 0 4 289.0 43,061 596 163,006 0 6 347.0 51,703 149 51,703 2,161 5 318.0 47,382 149 47,382 -2,161 6 347.0 51,703 298 103,406 4,321 5 318.0 47,382 298 94,764 -4,321 5 318.0 47,382 447 150,788 2,161 6 347.0 51,703 447 146,467 -2,161 5 318.0 47,382 596 198,170 0 6 347.0 51,703 596 198,170 0 4 289.0 43,061 149 43,061 2,310 7 377.0 56,173 149 56,173 -2,235 4 289.0 43,061 298 86,122 4,619 7 377.0 56,173 298 112,346 -4,470 3 258.0 38,442 447 124,564 2,310 8 407.0 60,643 447 172,989 -2,235 3 258.0 38,442 596 163,006 0 8 407.0 60,643 596 233,632 0 2 228.0 33,972 149 33,972 2,235 9 436.0 64,964 149 64,964 0 2 228.0 33,972 298 67,944 4,470 9 436.0 64,964 298 129,928 0 1 198.0 29,502 447 97,446 2,235 9 436.0 64,964 447 194,892 0 1 198.0 29,502 596 126,948 0 Sum of minimum Moment Deviations -17,880 Sum of maximum Moment Deviations 17,880Sum of Minimum Moment Deviations -17,880 Sum of Maximum Moment Deviations 17,880 Page 4
Appendix 5 APPENDIX 5. OPTIONS TO IMPROVE ACCURACY A number of options are available that enable operators to deviate from standard assumed weights and may also provide relief from constraints required when assumed averages are used.
These options include:
1. Surveys. Surveys may be accomplished for passenger weights (to include carry-on bags), checked baggage weights, male/female ratios, and fuel densities. These surveys may be conducted for entire operator route systems, or by specific market or region. Surveys practices and data reduction must conform to the requirements defined in this advisory circular (AC). Use of surveys may allow an operator to use passenger and baggage weights less than the standard specified in this AC. Also, a survey may find that the assumed male/female ratio is incorrect and appropriate adjustments must be made. For example, let’s assume the following results from an approved passenger and baggage survey.
Male passenger weight (M) = 183.3 pounds Female passenger weight (F) = 135.8 pounds Difference between male and average passenger weights = 24.0 pounds Standard deviation of total sample (Sigma) = 47.6 pounds Male/female ratio (Pax Ratio) = 50.6 percent Checked baggage weight = 29.2 pounds Baggage checked plane-side = 21.3 pounds Carry-on and personal items weight (CO Wt) = 10.4 pounds Carry-on and personal items per passenger ratio (CO Ratio) = 0.82 pounds Survey conducted in summer months
The resulting assumed passenger weight for loading is expressed as:
Passenger Weight = (M × Pax Ratio) + (F × (1 - Pax Ratio)) + (CO Wt × CO Ratio) And is determined as:
Summer Passenger Weight = (183.3 × 0.506) + (135.8 × (1 - 0.506)) + (10.4 × 0.82) = 169 lb Winter Passenger Weight = 169 + 5 = 174 lb
Survey results would also be used to determine the additional curtailment for variations to passenger weight. Assuming a 19-seat aircraft in 2-abreast configuration in our example, the additional weight to be curtailed would be:
Additional Weight for Curtailment = (47 × 1.70) + 24 = 104 lb
Also in our example, the assumed checked baggage weight is 30 pounds. Plane-side loaded bags would be assumed to weigh 20 pounds. (These weights are the standard average weights provided for a no-carry-on baggage program as described in Chapter 2, Section 2).
2. Actual Weights. It is permissible to use actual weights in lieu of standard average, segmented, or survey-derived average weights (if applicable). Parameters that may use actual weights include passenger weights, checked baggage weights, carry-on bag weights, crew weights, and fuel density/weight.
Appendix 5
3. Passenger Cabin Zones and Row Count. Passenger cabins may be split up into zones provided an acceptable procedure for determination of passenger seating is included (e.g., use of seat assignments or the crew counts each seated passengers by zone). If zones are used, it may be reasonable for the operator to reduce the center of gravity (CG) passenger seating curtailment by accommodating variations within each individual zone separately and totaling the results.
Passenger row count allows the operator to reduce the seating variation by accounting for the row in which the passenger is actually seated.
An example of use of passenger zones follows.
Assume an aircraft interior as displayed in Figure 5-1.
FIGURE 5-1. SAMPLE AIRCRAFT INTERIOR SEATING DIAGRAM Assume that for weight and balance purposes, it is desirable to break up the cabin into passenger zones. Appendix 3 provides a sample calculation of curtailing for passenger seating variations using a hypothetical commuter category 19-seat aircraft with 3 passenger zones. A more accurate weight and balance calculation requiring less curtailment may be provided by increasing the number of passenger zones. For example, an increase to 5 passenger zones would result in the following:
The passenger zones will be determined as zone 1 (rows 1−2), zone 2 (rows 3−4), zone 3 (rows 5−6), zone 4 (rows 7−8), and zone 5 (row 9). Use of the window-aisle-remaining method will be used in each zone to provide a total curtailment to the CG envelope. (For this sample aircraft, window-aisle-remaining method simply becomes forward and aft end loading). For each zone, a zone centroid must be calculated by counting the total number of seats and averaging their location.
Zone 1 centroid = (2 x 198.0 + 2 x 228.0) / (2 + 2) = 213.0 in Zone 2 centroid = (2 x 258.0 + 2 x 289.0) / (2 + 2) = 273.5 in Zone 3 centroid = (2 x 318.0 + 2 x 347.0) / (2 + 2) = 332.5 in Zone 4 centroid = (2 x 347.0 + 2 x 377.0) / (2 + 2) = 392.0 in Zone 5 centroid = (3 x 436.0) / (3) = 436.0 in (Diagram courtesy of Raytheon Aircraft Company) Page 2
Appendix 5
Assuming the standard winter passenger weight of 189 pounds (as determined in Appendix 3) is used in the curtailment, the calculation of the total moment is required for comparison to the zone moment, assuming each passenger is seated at the centroid of each passenger zone. The total moment is found by summing the individual moments calculated at each occupied seat in the window-aisle-remaining progression.
Forward Curtailment Calculations Zone 1 Pax Row Arm Total Moment Zone Centroid Zone Moment Delta Moment 1 1 198.0 37,422 213.0 40,257 -2,835 2 1 198.0 74,844 213.0 80,514 -5,670 3 2 228.0 117,936 213.0 120,771 -2,835 4 2 228.0 161,028 213.0 161,028 0
Forward Curtailment CalculationsZone 2 Pax Row Arm Total Moment Zone Centroid Zone Moment Delta Moment 1 3 258.0 48,762 273.5 51,692 -2,930 2 3 258.0 97,524 273.5 103,383 -5,859 3 4 289.0 152,145 273.5 155,075 -2,930 4 4 289.0 206,766 273.5 206,766 0
Forward Curtailment CalculationsZone 3 Pax Row Arm Total Moment Zone Centroid Zone Moment Delta Moment 1 5 318.0 60,102 332.5 62,843 -2,741 2 5 318.0 120,204 332.5 125,685 -5,481 3 6 347.0 185,787 332.5 188,528 -2,741 4 6 347.0 251,370 332.5 251,370 0
Forward Curtailment CalculationsZone 4 Pax Row Arm Total Moment Zone Centroid Zone Moment Delta Moment 1 7 377.0 71,253 392.0 74,088 -2,835 2 7 377.0 142,506 392.0 148,176 -5,670 3 8 407.0 219,429 392.0 222,264 -2,835 4 8 407.0 296,352 392.0 296,352 0
Forward Curtailment CalculationsZone 5 Pax Row Arm Total Moment Zone Centroid Zone Moment Delta Moment 1 9 436.0 82,404 436.0 82,404 0 2 9 436.0 164,808 436.0 164,808 0 3 9 436.0 247,212 436.0 247,212 0
The curtailment for passenger seating variation is determined by adding the largest delta moments from each of the passenger zones. In our example, the curtailment to the forward CG limit for passenger seating variation is -22,680 inch-pounds (-5,670 + -5,859 + -5,481 + -5,670 + 0). Similarly, the curtailment to the aft limit of the CG envelope using the window-aisleremaining method loading from the most aft seat row moving forward (in each zone) would result in an adjustment of +22,680 inch-pounds. These curtailments compare favorably to the curtailments of + 36,666 inch-pounds determined in the sample provided for three passenger zones in Appendix 3.
Appendix 5
4. Actual Male/Female Counts. Loading systems may use separate male and female assumed passenger weights for each operation. If the operator’s weight and balance program is approved for use of male/female weights, then the operator must count the number of male passengers and female passengers separately. The male and female weights used may be from the development of standard passenger weight or they may be determined through an operator-developed survey.
Use of male/female weights may be for entire operations or for a particular route and/or region of flying.
An example of how male/female ratios can be applied to weight and balance systems follows.
Assuming the operator is using the survey results as described in subparagraph (1) above, the assumed male and female passenger weights, including average carry-on baggage, are computed as:
Male passenger weight (summer) = 183.3 + 10.4 × 0.82 = 192 lb Male passenger weight (winter) = 192 + 5 = 197 lb Female passenger weight (summer) = 135.8 + 10.4 × 0.82 = 144 lb Female passenger weight (winter) = 144 + 5 = 149 lb
The weight and balance manifest would provide for identification of male/female identification and the passenger weights would be summed accordingly. For instance, 7 male and 11 female passengers would result in a total passenger weight of (7 × 192) + (11 × 144) = 2,928 pounds.
5. Adolescent (Child) Weights. In most circumstances, an operator may consider any passenger who is less than 13 years of age and is occupying a seat to weigh less than an adult passenger. The standard average adolescent child weights can be found in Table 2-1 of Chapter 2.
6. Standard Weights with Approved No-carry-on Baggage Program.
Summer Passenger Weight = 184 lb Winter Passenger Weight = 189 lb Checked Baggage Weight = 30 lb each Baggage Checked Plane-side = 20 lb each
Inclusion in the no-carry-on baggage program does not preclude use of actual or surveyed weights for passengers, carry-on/personal items, checked baggage, or baggage checked plane-side.
7. Automation. Automation may also be used to provide a more accurate weight and balance program. Examples of automation include use of seat assignments for the determination of passenger moment and historical seating to determine passenger moment.
Appendix 6 APPENDIX 6. WEIGHT AND BALANCE CHECKLIST What operators should use this AC? Refer to paragraph 5 on page ii.
Does the operator use individual aircraft Operating Empty Weights (OEW) or Fleet OEWs? Refer to paragraph 102.
Does the operator have an individual aircraft weighing program or a fleet weighing program? Refer to paragraph 103.
Each operator must construct a loading envelope with curtailments. Refer to Chapter 1, Sections 2 and 3.
What is the aircraft cabin size? Refer to paragraph 5b and Table 1 on page ii.
a. If the aircraft is a large cabin aircraft, then refer to paragraph 200d:
Large Cabin Aircraft
1. For standard average weights, refer to Chapter 2, Section 2.
2. For survey-derived average weights, refer to Chapter 2, Section 3.
3. For actual weight programs refer to Chapter 2, Section 5.
4. For segmented weights refer to Chapter 2, Section 4.
b. If the aircraft is a medium cabin aircraft, then refer to paragraph 200e:
Medium Cabin Aircraft Treated as Large
1. See Large Cabin Aircraft items 1−4 above, and
2. If operator has a no-carry-on bag program, refer to paragraph 205.
Medium Cabin Aircraft Treated as Small
1. See Small Cabin Aircraft items 1−2 below.
c. If the aircraft is a small cabin aircraft, then refer to paragraph 200f:
Small Cabin Aircraft
1. If the aircraft meets the performance criteria stated in paragraph 200f(3)(a),
a. Refer to Chapter 2, Section 2 for standard average weights and Appendix 4 for additional CG envelope curtailment, or
b. Refer to Chapter 2, Section 3 for survey-derived average weights and Appendix 4 for additional CG envelope curtailment.
c. If operator has a no-carry-on bag program, refer to paragraph 205.
2. If the aircraft does not meet the performance criteria stated in paragraph 200f(3)(a), or the operator elects to use actual or segmented weights, then:
a. For actual weight programs refer to Chapter 2, Section 5.
b. For segmented weights refer to Chapter 2, Section 4.
c. If operator is using segmented weights and has a no-carry-on bag program refer to paragraph 205.
Page 1 (and 2)