The most common are strong tailwinds, obstacles, high descent angles and/or the final approach segment exceeds 30 degrees from the approach runway. .
Each scenario is different, but the fundamentals are the same: you need to get aligned with the best runway after you exit the clouds.But, if you just want to know how to fly them without crashing, read on.First, let me explain something, circling approaches aren’t “approaches” in the traditional sense. Figure 1 – Circling Approach Area Under the previous terminal instrument procedures (TERPS) criteria, the radii used to define the size of these arcs were rela… Or maybe a few examples:The obstacle evaluation area for the VOR/DME-A at Teterboro is based on a 1,000' MSL MDA for Category C and D aircraft and comes to 2.8 nm for Category C and 2.9 nm for Category D.Figure: Eagle County LOC/DME-C, from FAA AL-6403, Amdt 2B 05020.The obstacle evaluation area for the LOC/DME-C at Eagle, Colorado is based on a 9,140' MSL MDA for Category C and D aircraft and comes to 3.4 nm for Category C and 3.5 nm for Category D.Both aircraft at both airports are afforded enough protected airspace.c) wind speed: 46 km/h (25 kt) throughout the turn; andd) bank angle: 20° average or 3° per second, whichever requires less bank.Though the ICAO Documents don't offer as much background information about circling approach radii as does TERPS, it is clear from the examples that the radius from threshold used to construct their circling approach radii are considerably larger.AIM now reflects the expanded airspace but notes there are still (mostly) the tighter approaches.
While the approach was not listed as causal, the report did suggest that these tight tolerances did not allow large aircraft time to stabilize their approaches.Circling is a visual maneuver and you should never attempt a visual maneuver unless you can roll out on final at 600' at 2 nm from the threshold so as to provide a stabilized approach starting at 500'.
Most instrument airports have approaches to all runways.They are also dangerous when not properly planned and briefed. All you need is a yoke-mounted slide rule and you are all set. The protected airspace for a circle-to-land approach is defined by arcs of a specific radius based on the aircraft approach category defined in 14 CFR Part-97. When an aircraft intends to land on a runway for which no instrument approach procedure exists, it may descend on the instrument approach to another runway and, provided the required visual references are established at the circling Minimum Descent Altitude/Height, manoeuvre visually for landing on the desired runway. The turn radius of a 50,000 lb. Aerodrome operating minima (AOM) are calculated by operators based on information supplied by national authorities in their AIPs. But wait....there is one more step. This information typically consists of approach and departure procedures which assure safe separation between the aircraft and known obstacles located close to the intended flight path of the procedure in question.
But just because you are flying a Category C aircraft doesn't mean you can't fly using Category D minimums and therefore Category D radii and obstacle clearances.Rule of Thumb: You should never circle at the older TERPS Category C minimums and your minimums for circling should be no lower than 1,000' & 3 nm.United States Standard for Terminal Instrument Procedures (TERPS), Federal Aviation Administration 8260.3B CHG 25, 03/09/2012United States Standard for Terminal Instrument Procedures (TERPS), Historic, Federal Aviation Administration 8260.3B CHG 19, 05/15/2002Always remember that Eddie, when you get right down to it, is just a pilot. You can easily spot them because they have a letter after the type of approach.The example below is a VOR-A circling-only approach.Circling-only approaches do not allow a straight in approach so you will Circling approaches are a last resort.
The resulting enclosed area is the circling OEA [no secondary area].Figure: Teterboro VOR/DME-A Approach Plate, from FAA AL-890, Amdt 28 09015.Simple!