UAM.POL.VCA.140 Mass and balance, and loading

CENTRE OF GRAVITY (CG) LIMITS — OPERATIONAL CG ENVELOPE AND IN-FLIGHT CG

(a)Forward and aft CG limits are specified in the AFM. These limits allow for a proper trim setting for take-off and ensure that the certification stability and control criteria are met throughout the whole flight.

(b)The IAM operator should ensure that these limits are respected by:

(1)defining and applying operational margins to the certified CG envelope in order to compensate for the following deviations and errors:

(i)deviations of the actual CG at empty or operating mass from published values due, for example, to weighing errors, unaccounted modifications and/or equipment variations;

(ii)deviations in the distribution of baggage and cargo in the various compartments as compared with the assumed load distribution as well as inaccuracies in the actual mass of baggage and cargo;

(iii)deviations in the actual passenger seating from the seating distribution assumed when preparing the mass and balance documentation. Large CG errors may occur when ‘free seating’, i.e. freedom of passengers to select any seat when entering the VCA, is permitted;

(iv)deviations of the actual CG of cargo and passenger load within individual cargo compartments or cabin sections from the normally assumed mid position;

(v)deviations of the CG caused by any configuration change, unless already covered by the certified limits;

(vi)deviations caused by in-flight change of loading;

(vii)deviations caused by the difference between the actual passenger masses and standard passenger masses when such masses are used; and

(2)defining and applying operational procedures in order to:

(i)ensure even distribution of passengers in the cabin;

(ii)take into account any significant CG travel during flight caused by passenger/crew movement; and

(ii)take into account any significant CG travel during flight caused by fuel consumption, if applicable.

WEIGHING OF A VCA

(a)New VCA that have been weighed at the factory may be operated without reweighing if the mass and balance records have been adjusted for alterations or modifications to the VCA. VCA transferred from one EU operator to another EU operator do not have to be weighed prior to use by the receiving operator unless more than 4 years have elapsed since the VCA was last weighed.

(b)The mass and CG position of a VCA should be revised whenever the cumulative changes to the dry operating mass or CG exceed ± 0.5 % of the maximum landing mass or CG envelope respectively. This may be done by weighing the VCA or by calculation.

(c)When weighing a VCA, normal precautions should be taken consistent with good practices such as:

(1)checking for completeness of the VCA and equipment;

(2)determining that fluids are properly accounted for;

(3)ensuring that the VCA is clean; and

(4)ensuring that weighing is accomplished in an enclosed building.

(d)Any equipment used for weighing should be properly calibrated, zeroed, and used in accordance with the manufacturer’s instructions. Each scale should be calibrated either by the manufacturer, by a civil department of weights and measures or by an appropriately authorised organisation within 2 years or within a time period defined by the manufacturer of the weighing equipment, whichever is less. The equipment should enable the mass of the VCA to be established accurately. A single accuracy criterion for weighing equipment cannot be given. However, the weighing accuracy is considered satisfactory if the accuracy criteria in Table 1 are met by the individual scales/cells of the weighing equipment used.

Table 1: Accuracy criteria for weighing equipment

DRY OPERATING MASS OF THE VCA The dry operating mass includes:

(a)the pilot(s), technical crew member(s) and their baggage, as applicable;

(b)catering and removable passenger service equipment, if applicable.

MASS VALUES FOR THE PILOT(S) AND TECHNICAL CREW MEMBER(S), IF APPLICABLE

(a)The operator should use the following mass values for the pilot(s) and technical crew member(s), as applicable, to determine the dry operating mass:

(1)actual weighed masses including baggage; or

(2)standard masses, including baggage, of 85 kg.

(b)The operator should correct the dry operating mass to account for any additional baggage. The position of any additional baggage should be accounted for when establishing the CG of the VCA.

MASS VALUES FOR PASSENGERS, THEIR CLOTHING AND PERSONAL BELONGINGS AND FOR BAGGAGE

(a)When the actual number of passenger seats in the VCA is less than 6, passenger mass may be calculated on the basis of a statement made by, or on behalf of, each passenger plus a predetermined mass to account for clothing and personal belongings. The predetermined mass for clothing and personal belongings should be established by the operator on the basis of studies relevant to its particular operation. In any case, it should not be less than 4 kg for clothing and personal belongings such as an overcoat, an umbrella, a small handbag or purse, reading material or a small camera or laptop. The passengers’ stated mass and the mass of passengers’ clothing and personal belongings should be checked prior to boarding and, if necessary, adjusted. The operator should establish a procedure in the operations manual on when to select actual or standard masses and the procedure to be followed when determining mass based on verbal statements.

(b)When determining the actual mass by weighing, the passengers’ mass and the mass of passengers’ clothing and personal belongings should be weighed immediately prior to boarding the VCA.

(c)When using standard mass values, the standard mass values in Table 2 below should be used. The standard masses include the mass of any infant carried by an adult on one passenger seat. Infants occupying separate passenger seats should be considered ‘children’ for the purpose of this AMC.

Table 2: Standard masses for passengers — VCA with a total number of passenger seats of 19 or less

(1)As baggage is weighed separately, 6 kg may be deducted from male and female masses in Table 2.

(2)For operations where a survival suit is provided to passengers, 3 kg should be added to the passenger mass value.

(d)Mass values for baggage For VCA with 19 passenger seats or less, the actual mass of any passenger baggage carried in the VCA should be determined by weighing.

(e)Other standard masses may be used provided that they are calculated on the basis of a detailed weighing survey plan and that a reliable statistical analysis method is applied. The operator should advise the competent authority about the intent of the passenger weighing survey and explain the survey plan in general terms. The revised standard mass values should only be used in circumstances comparable with those under which the survey was conducted. If the revised standard masses exceed those in Table 2, then such higher values should be used.

(f)On any flight identified as carrying passengers whose mass, including clothing and personal belongings, are expected to significantly deviate from the standard passenger mass, the operator should determine the actual mass of such passengers by weighing or by adding an adequate mass increment.

PROCEDURE FOR ESTABLISHING REVISED STANDARD MASS VALUES FOR PASSENGERS AND BAGGAGE To establish revised standard mass values for passengers and baggage, the IAM operator should refer to the procedure described in AMC2 CAT.POL.MAB.100(e).

STATISTICAL EVALUATION OF PASSENGER AND BAGGAGE DATA The IAM operator may use the statistical method described in GM2 CAT.POL.MAB.100(e) to establish the mass of the traffic load.

GUIDANCE ON PASSENGER WEIGHING SURVEYS The IAM operator may use the guidance on passenger weighing surveys provided in

GM3 CAT.POL.MAB.100(e).