All Weather Operations — Page 70, Lesson 112

I want to walk you through the start of All Weather Operations. We're going to look at three key topics: the visual approach, VFR operating minima, and Special VFR. Let's begin with the visual approach. This is a specific type of IFR approach — that means even though you're flying under Instrument Flight Rules, you complete the approach with visual reference to the terrain. The formal definition is: an IFR approach completed with visual reference to terrain. Notice what this does not require: you do not need to see the aerodrome or the landing runway at the commencement of the approach. However, you must be capable of navigating the aeroplane with reference to the underlying terrain. There's a hard limit from EU-OPS 1: an operator is not to conduct visual approaches when the RVR — that's Runway Visual Range — is less than 800 metres. So if the RVR is below 800 m, visual approaches are prohibited. Now, VFR Operating Minima. The operator must ensure that VFR flights — Visual Flight Rules flights — are conducted in accordance with the visual flight rules and in the meteorological conditions shown in the table. Let's break that table down. First, the airspace classes are split into two groups. Group one: Classes A, B, C, D, and E — with a note I'll explain in a moment. Group two: Classes F and G. For Classes A through E, the criteria depend on altitude. Above 900 metres AMSL — that's 3000 feet — or above 300 metres AGL — 1000 feet — whichever is higher, you need a distance from cloud of 1500 metres horizontally and 300 metres — 1000 feet — vertically. The flight visibility requirement is 8 km at and above 3050 metres — that's 10 000 feet AMSL — and 5 km below 3050 metres AMSL. For Classes F and G, at and below 900 metres AMSL or 300 metres AGL — whichever is higher — the requirement is different. You must be clear of cloud and in sight of the surface. That's abbreviated CCISG. The flight visibility is 5 km, with a note I'll cover. Now, the notes. Note 1: The VMC minima for Class A airspace are included for guidance only. This does not imply acceptance of VFR flights in Class A airspace — in practice, VFR is generally not permitted in Class A. Note 2: When the height of the transition altitude is lower than 3050 metres — 10 000 feet — AMSL, you should use FL100 — Flight Level 100 — in lieu of 10 000 feet. So the 8 km visibility threshold shifts to FL100 if the transition altitude is lower. Note 3: This is important for certain aeroplanes. Category A and B aeroplanes may be operated in flight visibilities down to 3000 metres — that's 3 km — provided three conditions are all met: the appropriate ATS Authority permits use of a flight visibility less than 5 km; the circumstances are such that the probability of encounters with other traffic is low; and the IAS — Indicated Airspeed — is 140 knots or less. So if you're flying a Cat A or B aircraft, you can go down to 3 km visibility under those conditions. Finally, Special VFR. Special VFR flights are not to be commenced when the visibility — either flight visibility or ground visibility — is less than 3 km. And they are not otherwise conducted when the flight visibility is less than 1.5 km. So the starting limit is 3 km; once airborne, you need at least 1.5 km flight visibility to continue. There's a note that the criteria defined in ICAO Annex 6 is slightly different — so be aware that the numbers I just gave you are from EU-OPS, and ICAO may vary. That covers the visual approach definition and its RVR limit, the full VFR minima table with its notes, and the Special VFR visibility restrictions.