EU-OPS 1 - Extract 1 — Page 12, Lesson 16

We're starting a new part of the syllabus now — EU-OPS 1, the European operating rules that govern commercial air transport. This first extract is dense, so let's take it piece by piece. First, the centre of gravity limits. The regulation begins with the operational CG envelope. The certificated centre of gravity envelope is the range of CG positions, from forward to aft, within which the aircraft is certified to fly safely — that's the design limit. But the regulation says that, unless you account for the load distribution very precisely, you must apply operational margins to that certificated envelope. In other words, you shrink the usable envelope to give yourself a safety buffer. When can you avoid those margins? When seat allocation is applied — meaning passengers are assigned to specific seats — and when the effects of the number of passengers per seat row, of cargo in individual cargo compartments, and of fuel in individual tanks are all accounted for accurately in the balance calculation. So the precise method requires you to know exactly how many passengers sit in each row, exactly how much cargo sits in each compartment, and exactly how much fuel sits in each tank. If you don't do that precise accounting, you apply margins. And when determining those CG margins, you must consider possible deviations from the assumed load distribution. That's the key safety idea — you assume a load distribution, but people move, baggage gets shifted, so you need a margin that covers the worst realistic deviation. Now, if free seating is applied — that is, passengers can sit anywhere they like — the operator must introduce procedures to ensure corrective action by flight or cabin crew if extreme longitudinal seat selection occurs. So if all the passengers crowd to the front or all crowd to the back, the crew must take corrective action to bring the CG back within limits. And all of this — the CG margins and the associated operational procedures, including the assumptions about passenger seating — must be acceptable to the Authority. That's the regulator, the national aviation authority that oversees the operator. Then we move to the in-flight centre of gravity. This is a further requirement on top of the first one. The operator must show that the procedures fully account for the extreme variation in CG travel during flight caused by passenger and crew movement, and by fuel consumption and fuel transfer. So it's not enough to get the CG right at take-off — you must prove that throughout the flight, as fuel burns off and people walk around, the CG stays within limits at every moment. Now let's look at the second part of the extract — Appendix 1 to OPS 1.620 (f). This defines the area for flights within the European region. For the purposes of that paragraph, flights within the European region, other than domestic flights, are flights conducted within an area bounded by rhumb lines between a series of coordinates. A rhumb line is a line of constant bearing — it crosses all meridians at the same angle, so on a chart it appears as a straight line. The area is defined by a closed polygon of ten points, and the last point returns to the first to close the loop. Let me read them out. Starting at N7200 E04500 — that's 72 degrees north, 45 degrees east, up in the far northeast. Then down to N4000 E04500 — 40 north, 45 east. Then to N3500 E03700 — 35 north, 37 east. Then N3000 E03700 — 30 north, 37 east. Then west to N3000 W00600 — 30 north, 6 west. Then N2700 W00900 — 27 north, 9 west. Then N2700 W03000 — 27 north, 30 west. Then north to N6700 W03000 — 67 north, 30 west. Then N7200 W01000 — 72 north, 10 west. And finally back to the start, N7200 E04500. So this polygon sweeps from the northeast corner of Europe, down the eastern Mediterranean, across North Africa, out into the Atlantic, and back up to the Arctic. Any flight conducted within this area, other than a domestic flight, counts as a flight within the European region for the purposes of that regulation. And there's a figure — Figure 1 — that depicts this region graphically, which I'd recommend you study alongside these coordinates. That's the substance of this extract — the operational CG envelope with its margins and the precise accounting requirements, the in-flight CG travel requirement, and the defined European region boundary.