Hold me, thrill me: if you're doing them right, holds are anything but thrilling. but they can be useful at times.
In fact, I'm hearing more and more reports from pilots being put into holding patterns in busy terminal airspace. Most recently, I ran across a friend who flies a turboprop-converted Beech Bonanza, a Cessna Citation and (with a copilot) a Lear 55. He says he's regularly assigned holds in the Dallas area. Frequently he's assigned a hold at a controller-defined fix (e.g., "XYZ 050 radial, 20 DME fix") that is not published anywhere on the charts or in his panel-mounted, GPS-driven display database. "It's a big problem for a single pilot flying IFR," my friend says.
TYPES OF HOLDS
The FAA's Instrument Flying Handbook (FAA-H-8083-15B) makes it sound easy: "Holding is a predetermined maneuver that keeps (an] aircraft within a specified airspace while awaiting further clearance from ATC." Holding is a basic skill we all demonstrate on our practical test for the instrument rating.
Once rated, it's required that we demonstrate holds and holding-pattern entries on instrument proficiency checks (IPCs). If we maintain instrument currency through recent activity, we have to log a holding pattern within the past six months. Usually this is done by flying one hold--often only one--at the end of a simulated missed approach. Clearly this is a very minimum standard of proficiency. And it demonstrates only one IFR holding scenario: a published hold in all the databases and on the charts, one you can study at any time before flying the approach or entering the hold.
While we all need to know how to hold, it's something I commonly see done incorrectly when I conduct IPCs. Since it's a task we can be asked to perform at any time when on an instrument clearance--and one that at least in some areas may be becoming more common--let's review holding procedures, then look at some workload-reducing tricks for flying published and unpublished holding procedures in a busy, single-pilot cockpit. There also are a few common misconceptions and errors we need to discuss. But let's start by discussing the several situations where holding patterns are commonly used:
Missed approach. This is the type of hold we usually practice. Fly an arrival procedure down to minimums, be unable to visually acquire the runway or runway environment, and power up to climb along a published route to a safe altitude. Then, we'll arrive at a holding fix and begin flying the familiar racetrack pattern until cleared to an alternate airport or to fly the same or another approach.
In lieu of a procedure turn. Flying an instrument approach below radar coverage, after a transponder failure that makes it too hard for controllers to vector you onto final, or when the radar is out of service? You may have to fly an "own navigation" instrument approach. Sometimes, when airspace, terrain or conflicts with other arrival and departure procedures preclude a standard 10-miles-from-the-fix procedure turn, the arrival may instead specify a holding pattern "in lieu of" the procedure turn. Fly to the fix, enter the hold and intercept the final approach course inbound. Pilots generally remember that this possibility exists, whether they've practiced it any time recently or not.
Flow control. Weather frequently creates delays in busy terminal airspace. When ATC assigns holds for spacing, it's to maintain the distance between aircraft so each has time to complete an arrival procedure. These are the sort of pop-up, often minimum-notice holding patterns my friend was lamenting. Usually, but not always, this type of hold will be published.
Delaying action. Similarly, holds may be assigned when a runway is temporarily closed. Examples of this type of scenario include an emergency aircraft inbound ahead of you, a gear-up landing that has blocked a runway, delays for snow removal or any other reason a runway may be closed for a while but not so long that all aircraft will have to go elsewhere. The nature of these types of runway closures are such that a "delaying action" hold can happen with very little notice, and may not always be at a published holding fix.
Climbs and descents. It's fairly rare, but some IFR departure and arrival procedures employ a holding pattern used by pilots to climb or descend to/from a safe altitude over a small geographic area. When designed into a standard arrival procedure (STAR) or standard instrument departure (SID), it's usually in mountainous areas, and more commonly needed during high density altitude conditions.
Okay; that covers when you may be expected to hold. A common IFR error, however, is confusion about how to enter a hold. Let's refresh.
You know what? Entering a holding pattern really is easier than most of us think. All that guidance about direct, parallel and teardrop holding pattern entries? Except on practical tests (checkrides), when the applicant for a certificate or rating is required to use the "correct" holding pattern entry, the di-rect/parallel/teardrop guidance is merely recommended as a possible way to enter a hold.
Remember what the Instrument Flying Handbook says: A holding pattern simply "keeps [an] aircraft within a specified airspace." How a pilot enters a hold, and what he or she does once in the holding airspace, is not terribly important. What is important is that the pilot remains in the airspace designated for the hold and at the cleared altitude.
And there's a lot of airspace available to the pilot assigned a holding pattern. Holding airspace consists of four areas relative to the holding fix. The "holding side" of the pattern, outward from the holding fix, is eight nm long and eight nm wide. The "non-holding sides," ahead of the fix and also opposite the holding side, are each four nm deep. So, in the hold, you have a 12 nm by 12 nm box-144 square nm--all to yourself. You'll have even more protected airspace in a hold at higher altitudes. Stay at your assigned altitude, because other airplanes may be holding above or below you. But otherwise, do whatever you wish, as long as you remain in this protected area of the holding airspace.
Unless you're told otherwise (by ATC or as depicted on a chart or by a database), the standard holding pattern uses right turns. Cross the holding fix inbound in the hold, then make a right turn to remain in the hold. Why right turns, when left-hand turns are the standard in traffic patterns and many other procedures? Your guess is as good as mine. I've seen a common IFR error, however, of uncertainty as to which direction to turn in a hold, when flying with instrument-rated pilots for the first time.
KNOW YOUR LIMITATIONS
How big should you make your holding pattern legs? How long should you fly outbound during a holding pattern entry? How soon before a hold will we be given holding instructions? What are the speed limits in a hold? How do we adjust for winds in a hold? Are those enough questions?
Leg lengths. In a standard holding pattern the pilot is expected to adjust the outbound course time so that from wings level on the inbound course until crossing the holding fix takes one minute. Above 14,000 feet this standard increases to 1.5 minutes.
Generally, the first time around a hold, just coming out of a holding pattern entry, will not be perfectly timed to this standard. On each subsequent turn in the hold, start a timer when leveling the wings on the inbound course. It should take one minute (again, 1.5 minutes above 14,000 feet) from wings-level to crossing the holding fix. If the time is too short, fly about the same amount of time extra on the outbound course before turning back in. Start your outbound timer when wings level from the outbound turn or abeam the holding fix (if you can identify it), whichever is longer. You'll never get it perfect; it's a matter of timing each inbound leg and adjusting the outbound to approximate the correct inbound course length.
Often, ATC will assign a distance in lieu of timing a holding pattern, i.e., "fly three-mile legs" or similar. In that case, estimate and adjust your turn inbound to approximate the assigned inbound leg length. Feel free to request a different inbound leg length; you'll either get it or you won't.
Advance warning. Normally, ATC will provide at least five minutes' warning before you reach a holding fix. If the holding pattern is not published on a chart or in a GPS database, the controller will give you the following information:
* Direction from the fix you will hold (N, NE, E, SE, etc.)
* Name or identification of the holding fix or the facility used to identify the fix.
* Radial or bearing on which to hold. Your inbound course is the reciprocal heading of this radial or bearing. Put another way, this is the approximate heading you'll be flying when inbound to the fix in the holding pattern.
* Leg length, if assigned in lieu of the standard time of the inbound leg.
* Direction of turns in the hold, if left-hand turns are assigned.
* Expect Further Clearance (EFC) time. The EFC serves two purposes: it is an indication of the longest time you should expect to remain in the hold (for your fuel planning purposes), and it is the time you should depart the hold if you lose ATC communications while holding.
Speed limits. You're expected to slow to holding speed so that you arrive at the holding fix on that speed. At 6000 feet and below, the maximum permitted holding speed (unless specifically directed otherwise) is 200 knots indicated airspeed. From 6001 to 14,000 feet the speed limit is 230 KIAS. Aircraft may be limited to 210 KIAS when directed by an icon on the chart. Above 14,001 feet, the maximum holding speed is 265 KIAS, unless limited to 175 KIAS on the chart.
Wind correction. Of course, you'll need to adjust your inbound and outbound headings to fly the proper ground track inbound, and to assure you remain within the protected airspace. A rule of thumb is to determine the crab angle necessary to compensate for wind drift on the inbound course, and then double the wind correction angle, into the wind, on the outbound leg. You'll end up flying an oblong, egg-shaped pattern, but it will keep you in protected airspace and as close as possible to the correct ground track on the inbound leg.
Holding patterns and hold pattern entries take some mental bandwidth, but there are a few techniques you can use to reduce the workload. Let's look at a couple of workload-reducing tricks for holds in the single-pilot cockpit, and some common holding pattern errors.
Slow down. Your aircraft may not be capable of flying at the holding pattern speed limit in level flight. Even so, there's no need to fly around the hold at cruise speed. After all, you're in the hold for a reason, often to stay there a while until ATC figures out what to do with you next, or allowing you to gather information and make a decision in response to a controller's query of "What are your intentions?"
Slowing the airplane down and trimming off the pressures before you enter a hold gives you more time to maneuver through the entry and pattern. Depending on the reason for the hold, slowing clown well before reaching it--and informing ATC you're reducing airspeed--can both minimize the time you're in the hold or eliminate the need for it altogether.
Draw the picture. This is technique that helped me through my IFR practical test and which I still use today. If assigned a hold, I'll sketch it out on my kneeboard, including the inbound and outbound course and heading. I'll envision myself flying inbound on the inbound course and turning right or left as appropriate. And I'll sketch out my holding pattern entry, including a computed initial heading for the entry--all to know precisely how I'll enter and fly the hold before I cross the fix for the first time.
Use the autopilot. You may have a top-of-the-line VVAAS-enhanced GPS navigator flying the hold for you--while you closely monitor it. You may not have such equipment but still have the capability to fly the hold in heading and altitude hold modes. Use whatever technology you have to reduce your workload and enhance your ability to see the "big picture" while you fly the hold.
Use the GPS OBS mode when assigned a hold at something other than a published fix. Enter a user-defined waypoint (using the radial/ distance information given by ATC) for the holding fix. After navigating to that fix, select the OBS mode and dial in the direction from that fix that gives you the inbound course (i.e., the reciprocal of the direction assigned to hold from the fix). It may not draw the holding pattern on your display, but it will give you a depiction of the inbound course, and signal when you cross the holding fix inbound. Use your autopilot's heading and altitude hold modes, if available.
REQUESTING A HOLD
Here's a little-used but powerful workload-reducing trick for single-pilot IFR: request to be assigned a holding pattern. When would you want to do that? If you need a little extra time to descend before beginning a procedure, or a little extra time to climb to reach a comfortable altitude before departing on course, ask to be given a holding pattern. If you're experiencing an abnormal condition, such as an electrical abnormality or the need to manually extend landing gear, request a hold at a safe altitude in which to run your checklist and troubleshoot as needed. Do you want to evaluate weather information or brief for an approach? Ask for a hold. It's an unusual move, but asking for a hold is a great way to take most navigation chores out of the mix while you concentrate on more-immediate needs.
This has been a fairly remedial look at holding patterns. I'm getting more and more questions about holding patterns from experienced pilots, however, and see a lot of the same mistakes made by high-time IFR fliers when I fly with them for the first time. So a little review is a good thing. There's quite a bit more about holding patterns beginning on page 10-10 of the Instrument Flying Handbook. It's worth a good look
Tom Turner is a CFII-MEI who frequently writes and lectures on aviation safety.
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|Title Annotation:||INSTRUMENT FLIGHT|
|Author:||Turner, Thomas P.|
|Date:||Dec 1, 2014|
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