EU-OPS 1 - Extract — Page 12, Lesson 14

Right, let's pick this up with the fleet mass evaluation rules. We're inside EU-OPS 1, the operational rules, and we've just covered how you establish empty mass. Now we're looking at the fleet values system — the legal shortcut that lets an operator use one set of mass figures for a whole group of identical aeroplanes instead of weighing every single one. Here's the key rule I want you to hold onto: to add an aeroplane to a fleet that's already operating with fleet values, the operator must verify — by weighing or by computation — that the new aeroplane's actual values fall within the tolerances specified in subparagraph 2(ii). So you can't just bolt a new aircraft onto the fleet; you have to prove it matches the fleet's numbers within the allowed tolerance band. And there's a time limit attached: the fleet values must be updated at least at the end of each fleet mass evaluation. Now, the arithmetic — how many aeroplanes must you actually weigh to obtain those fleet values? Let's call "n" the number of aeroplanes in the fleet using fleet values. Between two fleet mass evaluations, the operator must weigh a minimum number, and that number depends on the fleet size. If the fleet has 2 or 3 aeroplanes, you weigh all of them — the minimum is n. If the fleet has 4 to 9 aeroplanes, the minimum is (n + 3)/2. And if the fleet has 10 or more, the minimum is (n + 51)/10. So for a fleet of 10, that's (10 + 51)/10 = 6.1, which means you'd weigh at least 7 — you round up to the next whole aeroplane. There's a selection rule too: when you're choosing which aeroplanes to weigh, you must pick the ones that have not been weighed for the longest time. That keeps the data fresh across the whole fleet. And the interval between two fleet mass evaluations must not exceed 48 months — four years is the absolute ceiling. Now the weighing procedure itself. The weighing must be accomplished either by the manufacturer or by an approved maintenance organisation — so it's not something just anyone can do. Then there are normal precautions, consistent with good practices: checking for completeness of the aeroplane and equipment; determining that fluids are properly accounted for; ensuring the aeroplane is clean; and ensuring the weighing is accomplished in an enclosed building. Each of those matters because any dirt, missing equipment, or unaccounted fluid would corrupt the empty mass figure. The equipment itself has strict rules. Any equipment used for weighing must be properly calibrated, zeroed, and used in accordance with the manufacturer's instructions. Each scale must be calibrated — either by the manufacturer, by a civil department of weights and measures, or by an appropriately authorised organisation — within two years, or within a time period defined by the manufacturer of the weighing equipment, whichever is less. So you take the shorter of those two intervals. And the equipment must enable the mass of the aeroplane to be established accurately. Then we move to special standard masses for the traffic load. Beyond the standard masses for passengers and checked baggage, an operator can submit for approval to the Authority standard masses for other load items. So the regulator can approve standardised figures for, say, cabin baggage or cargo containers, as long as they're submitted and approved. Finally, aeroplane loading. The operator must ensure the loading of its aeroplanes is performed under the supervision of qualified personnel. The loading of the freight must be consistent with the data used for the calculation of the aeroplane mass and balance — you can't load something differently from how you calculated it. And the operator must comply with additional structural limits: the floor strength limitations, the maximum load per running metre, the maximum mass per cargo compartment, and/or the maximum seating limits. Those are the structural constraints that sit on top of the mass and balance calculation. So the whole picture is: fleet values give you a legal averaging system, but they're tightly controlled — you weigh a defined minimum number, you keep the intervals within 48 months, you use calibrated equipment under controlled conditions, and you respect both the mass limits and the structural limits when you actually load the aeroplane.