availability of markings, lighting, runway surface and width, distances available and your experience (inexperienced crews should add 100 feet and 200m to these figures). Destinations Landing Distance requirements must be satisfied on both the most suitable runway for landing in still air, and any you may need because of forecast wind conditions. You must not descend below the en route minimum altitude (MOCA) until your position has been positively identified, and you must reconfirm it afterwards (well, you would, wouldn't you?). You should also have a copy of the let-down plate available, with all required ground and airborne aids being serviceable. When in IMC, you should not descend below MSA (as on the chart) until established in the approach or hold procedure. As the safe altitude is based on correct entry procedures, it will cover a certain area of ground, so if you're given something non-standard, such as a very long downwind leg that takes you off the chart, beware! The Decision Height (or Minimum Descent Height, depending on the sort of approach) is the height at which you must go around if you can't see anything vaguely resembling a runway. If the Cloud Ceiling is lower than this, you may (unless prohibited by national regulations) carry out one approach to check if you can see anything (known in the trade as 'assessing the visual reference available'), but Missed Approach action must be taken at Decision Height on a precision approach if you can't. A precision approach is an ILS or PAR. A non-precision approach is basically anything else, such as VOR or ADF, which only has azimuth guidance (that is, only left or right, without up or down). It is characterised by large steps, that is, major descents at certain stages requiring large power changes that can be a pain with an engine out. It’s often a good idea to keep a consistent glide path as much as possible throughout a nonprecision approach – the minimum heights at each step are just that – minimum heights. There’s nothing to stop you being above them if you 64 Operational Flying are descending under control (300 feet per mile gives you 3°). On non-precision approaches, if visual reference has not been established by Minimum Descent Height, you may fly level at that height if your heading is within 15° of the runway QDM, and you may go down further if you can see where you're going, if you can land at normal touchdown speed. This, unfortunately, raises the temptation of a dirty dart for the runway if you see it, without really being in a position to cope with the situation— you are in a high drag landing configuration, and have been for some time. There are no performance figures for go-arounds under those conditions. If you can't see anything by your |