| by |
Paul Bertorelli |
| This article originally appeared in IFR MAGAZINE and is reprinted here by permission.
|
For reasons having a little to do with human failings and a lot
to do with the FAA, remembering how to enter a hold correctly
requires a level of effort that's disproportionate to the importance
of the task. It's like learning parallel parking for a driver's
test. You practice, get good at it, show the examiner you can
do it, and then promptly forget about it.
It should be (and once was) a lot simpler. Back in beginning (pre-1961)
before there were FAA-recommended entries, a pilot simply flew
to the holding fix, turned in the shortest direction to the outbound
course and then proceeded with the racetrack pattern. Nobody much
worried if the turn was a little longer than the shortest possible.
At DC-3 speeds, the airplane wasn't likely to blunder far enough
to cause much trouble before things got sorted out.
Jets changed the picture.
Higher speeds translated to larger turn radii and where a relatively
slow airplane could could lumber into the hold within a few miles
of the fix, a 707 needed a lot more airspace. One of the FAA's
responses to this was larger holding patterns graduated by altitude
and the three pattern entry methods every instrument student must
learn and master. The theory was that if pilots had a uniform
procedure for entering holds, they'd be less likely to blow the
entry and thus precious airspace would be conserved.
Of course, the theory ignores that fact that many general aviation
airplanes still cruise at less than DC-3 speeds but, by in large,
the hold entries do work. The problem is remembering them or at
least not letting them get in the way of a method that does work.
Just turn outbound
The AIM not withstanding, some instructors still teach the best
way to enter a hold is the original way, which is to simply fly
to the fix and turn in the shortest direction to the outbound
course. The shortest turn back to the fix will get the pilot established
in the racetrack pattern in fairly short order. Flight examiners
might not approve of this technique for checkride purposes but
how often have you had a DE along when you've been assigned a
real-life hold? Besides, it's easy to remember.
In practice, all you have to do is fly directly to the holding
fix, make the turn outbound and fly for a minute or so before
turning back toward the fix. If you know you've got a strong headwind
or tailwind, adjust your timing to suit the conditions. Curiously,
the turn-to-the-outbound technique often results in the equivalent
of the teardrop, parallel or direct entry. The exception is when
you're approaching the fix already on the correct heading for
the outbound course. In this case, you'll cross the fix aligned
with the inbound course but going in the opposite direction. To
get turned around, the AIM would have you initiate a parallel
or teardrop entry. However, if you're using the turn-to-the-outbound
method, simply cross the fix then head back to it with a turn
toward the holding side of the course. Once back at the fix, commence
the racetrack. This method—which is kind of a reverse teardrop—isn't
quite as neat as the AIM-approved teardrop, but it'll work.
Suppose you get confused and turn the wrong way? This shouldn't
be cause for panic, at least for a pilot in a slow airplane. As
shown at direction, the protected area around a published hold
is much larger than the holding pattern itself. And the higher
the altitude, the larger the protected area. So unless you're
in a very fast airplane, there's plenty of airspace to get reestablished.
DG as crutch
Some pilots can visualize a holding entry only by sketching it
right on the chart. That's certainly an option, albeit an awkward
one. Another way to accomplish the same thing is to put the DG
or HSI to work as a visual aid. Even pilots who busted pattern
analysis on their aptitude tests can manage this one.
Step one, as shown in the
drawing, is to divide the DG into segments that correspond to
teardrop, parallel and direct entries. To do this, strike an imaginary
line across the face of the instrument that's 70-degrees off the
vertical. (Or 20 dgerees of horizontal, if your prefer)
For standard turns to the right, the right side of the line should
be angled upward (as shown). For left turns, the left side should
be angled upward. Another imaginary line extends downward from
the DG's lubber line to the angled line, dividing the upper half
of the instrument face into two segments. Next, get established
on a heading towards the holding fix, be it a VOR, NDB or intersection.
To determine the entry type, just read the numbered radial or
bearing specified in the holding clearance along the outer ring
of DG compass card. If the radial falls in the teardrop sector
of your imaginary DG segments, use a teardrop entry; if in the
parallel sector, use that type of entry and so on.
If you're holding at an NDB, make sure you're clear on whether
the bearing given is TO or FROM the beacon. Published NDB holds
over approach fixes usually depict the inbound course so if the
DG-crutch method is to work in this instance, plug in the reciprocal
along the DG's card.
Although this method is nearly foolproof, you do need to remember
which direction to turn to both begin the entry and to intercept
the inbound course. One trick is to visualize the inbound course
as a line extending from the outside of the compass card to the
center of the DG. It should then be obvious which way to turn
to start the entry.
Cheap tricks
If all else fails, you can always buy one of the gadgets meant
to simplify hold entries. A $20 bill will buy a nice selection,
making them about the cheapest things the would-be Compleat Pilot
can own.
The simplest are the standard plastic chart plotters. In addition
to having several mileage scales and compass roses, these have
holding patterns (and their entries) printed right on them. Jeppesen
makes one called the PV-5 for its charts, Sporty's sells one of
its own for NOS charts. Both are under ten bucks.
The principle is not terribly hard to grasp. You simply place
the holding pattern over the fix, correctly oriented on the holding
course and with the turns in the correct direction. Once you've
figured out your heading to the fix and thus your position, the
plotter tells what type of entry to use. The scales not withstanding,
I think the Sporty's version works better for hold entries. The
pattern is larger and bolder than the Jeppesen, which fades illegibly
into the clutter around the fix. If you're a Jeppesen user, the
Sporty's plotter does have three of the common scales found on
Jepps enroute charts.
One thing the plastic plotters don't do is tell you the inbound
and outbound courses. Jeppesen has an answer to that, too. For
$7.95, it's a little circular computer that looks kind of like
one of those cheap E-6Bs. You dial the inbound course into a clear
plastic window then read the type of entry underneath along an
outer ring, where the inbound holding course is also displayed.
The device also displays the correct entry heading once you've
hit the fix and the outbound heading as well.
It's an excellent teaching aid but I found that it has one confusing
flaw. The instructions say "set inbound course of holding
pattern from chart or controller." Unfortunately, controllers
don't generally give the inbound, they give a cardinal direction
and/or a specific radial:"Hold southwest on the 220 radial."
Sure, I can get the inbound by noodling the reciprocal but if
I'm going to use a crutch for this stuff, I want it do everything.
The simplest gadgets are the often the best and that's certainly
true with holding entry aids. The Holdicator is nothing more than
a piece of clear, static-cling plastic with a holding pattern's
outbound turn silk-screened on it. Once you're inbound to the
fix, you're supposed to stick it right to the glass of the DG,
with the Holdicator's inbound course aligned with the cardinal
direction or radial given in the clearance. It's then child's
play to read the type of entry and entry heading right on the
DG. The Holdicator has little symbols to indicate whether a teardrop
or parallel entry is required but these really aren't necessary.
The entry type is quite easy to visualize once you know the aircraft's
relationship to the pattern.
When it's not in use, you can leave the Holdicator plastered to
the DG or, if that's a bother, stick it on the storm window or
some other out-of-the way place. A real bargain, the Holdicator
costs $2.95 from Nelson Aviation Products, Box 2889, Littleton,
Colo. 80161, or Aviation Training Center, 7201 Perimeter Road S., Seattle, WA
98108, postage paid.
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