Holding Procedures — Page 214, Lesson 286

Let’s start with the big idea: holding is the aviation equivalent of temporary parking. You can’t stop an aeroplane in mid-air — unless you’re flying a rotorcraft — but you can stay in the vicinity of a radio navigation facility for as long as you need, fuel permitting. So if you’re losing time, or if the weather is bad, or traffic is heavy, holding is your way to buy time while staying safely in the system. To hold, you need to fly accurately and navigate with reference to a radio navigation aid — a VOR or an NDB — or to a fix position. A fix is simply a defined point in space you can identify. In fact, in bad weather or at peak traffic, you’ll be lucky to get a straight-in approach. All instrument arrivals start from a holding pattern established at the IAF — that’s the Initial Approach Fix, the point where the approach procedure begins. Now, here’s how the stack works. Aircraft are “stacked” one on top of another, with vertical separation applied — that’s 1000 feet between each level. When the bottom aircraft departs the holding pattern to fly the approach, the ones above are “shuttled” — that means they’re descended in the stack, one at a time, to a lower level. So the whole column steps down as each aircraft leaves. Next, a deviation warning. If you deviate from the in-flight procedures for holding, you risk excursions beyond the perimeters of the holding areas — those perimeters are established in accordance with the provisions of PANS OPS. PANS OPS is the ICAO document, Procedures for Air Navigation Services — Aircraft Operations. The procedures described in PANS OPS relate to right-turn holding patterns. For left-turn patterns, the entry and holding procedures are symmetrical with respect to the inbound holding track — that is, they’re a mirror image. Now the shape and terminology. A standard holding pattern has starboard turns — that means right turns. If port turns — left turns — are required, the approach plate will be annotated to indicate that fact. A left-hand pattern is a mirror image of the standard pattern. Let me show you the geometry. Picture a racetrack: you fly outbound on one leg, turn, fly inbound on the reciprocal track, turn again, and repeat. The inbound leg is the one you fly toward the holding fix — the radio facility or fix you’re holding at. The outbound leg takes you away from it. The turns connect the two legs, and the whole thing forms an oval. In a standard pattern, all turns are to the right; in a non-standard pattern, all turns are to the left, and the plate will tell you so. That figure shows the holding pattern terminology — the inbound track, the outbound track, the turns, and the fix. The key point is that the pattern is defined by the inbound holding track, and the entry and holding procedures are built around that. So to summarise what you need to remember: holding is temporary parking in the air, done at a VOR, NDB, or fix. Aircraft stack with 1000-foot separation, and they shuttle down one at a time as the bottom aircraft departs. Deviations risk excursions beyond PANS OPS holding area perimeters. Standard patterns turn right; left-turn patterns are the mirror image and are annotated on the plate. That’s the foundation — from here we’ll build the entry procedures and the speed limits.