Rules of the Air — Page 122, Lesson 194

Let’s pick up with the Visual Flight Rules, starting at paragraph 6.59. This is the heart of how we fly when we’re not on an instrument flight plan, and I want you to think of it as a set of hard limits on when VFR is even legal. First, the foundation: VMC, which stands for Visual Meteorological Conditions. With the exception of special VFR, which we’ll call SVFR and cover later in paragraph 6.77, VFR is only permitted in VMC. So the rule is simple: if you’re flying VFR, you must be able to see and navigate visually. Now, what happens if the weather deteriorates mid-flight and you can no longer continue in VMC? The pilot must do one of four things. You can land while you’re still able to maintain flight in VMC. You can change your route to keep flying in VMC. You can file an IFR flight plan and continue under IFR. Or, if you’re inside a CTR — that’s a control zone — you can request an SVFR clearance. So the moment VMC is lost, you have four legal exits, and you must pick one. Next, take-off and landing conditions, paragraph 6.60. Unless authorized by ATC, VFR flights are not allowed to take off or land at an aerodrome in a CTR, nor enter the ATZ — the aerodrome traffic zone — or the traffic pattern, under two specific conditions. First, when the cloud ceiling is less than 450 metres, which is 1500 feet. Second, when ground visibility is less than 5 kilometres. So those are your hard minimums for VFR operations at an aerodrome in controlled airspace. If the ceiling is below 450 metres or visibility is below 5 kilometres, you need ATC authorization to operate. Now, paragraph 6.61 covers prohibitions on VFR flight. Between sunset and sunrise, or during any other period specified by the ATS authority — that’s the Air Traffic Services authority — VFR flights must be operated in accordance with the conditions that authority requires. So night VFR is possible, but only under the authority’s specified conditions. There are also absolute prohibitions. VFR flights require an ATC clearance to operate above FL200 — that’s flight level 200, which is 20,000 feet on the standard pressure setting. They also require clearance to operate at transonic or supersonic speeds. And VFR flight is not permitted above FL285 where RVSM is applied — RVSM is Reduced Vertical Separation Minimum, and above that level, VFR is simply banned. Then there are height restrictions. Except when taking off and landing, or when specially approved by the authority — for example, air displays — VFR flight is not allowed over the congested areas of cities, towns, or settlements, or over an open air assembly of persons, at a height less than 300 metres, which is 1000 feet, above the highest obstacle within a radius of 600 metres from the aircraft. So over a city, you must stay at least 300 metres above the highest obstacle within 600 metres of your aircraft. And separately, VFR flight is not allowed at a height less than 150 metres, which is 500 feet, above the surface — that’s ground or water. So those are your two minimum heights: 300 metres over congested areas, 150 metres elsewhere. Finally, paragraph 6.62 covers VFR flight levels. In level cruising flight above the transition altitude — which is normally 3000 feet AGL, that’s above ground level — VFR flight must be conducted at a VFR flight level appropriate to the magnetic track of the aircraft, in accordance with the semi-circular rule defined in paragraph 6.74. So the semi-circular rule assigns flight levels based on your magnetic heading, and we’ll cover that in detail shortly. When operating as a controlled VFR flight within controlled airspace, which we call CAS, the flight level or altitude will be specified by ATC in the ATC clearance for that flight. And VFR flights must comply with ATC instructions in three situations: when operating in class B, C, or D airspace — note that in class A, VFR flight is not permitted; when forming part of aerodrome traffic at controlled aerodromes; or when operating as special VFR flights. So the key takeaway here: VFR is a privilege with strict limits — on visibility, on ceiling, on height, on flight level, and on airspace class. Every one of those limits is there to keep you separated from other traffic and from terrain. Let’s look at the figures that illustrate the IFR and VFR flight levels up to and including FL, and above FL, to see how the semi-circular rule lays out on the altitude scale. And here’s the reduced vertical separation minima special VFR figure, which shows how SVFR fits into the vertical separation scheme. Now, before we move on, do you have any questions about these VFR limits — particularly the height restrictions or the flight level rules?