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Holding

Instrument Procedures

I was attending an Air Force instrument school refresher back in 1982 when the instructor was giving each pilot a holding problem that ended with, "which way do you turn?" He asked the fighter pilot sitting to my left who said, "I would declare an emergency." When asked why he would do that, the pilot said, "Real pilots don't hold."


 

Holding Pattern Timing

Figure: Holding pattern timing, from Eddie's notes.

  • Holding Instructions — The U.S. has unique instruction procedures that you certainly need to know anyplace the FAA rules are in place, but they don't apply under standard ICAO procedures.
  • Entry Procedures — U.S. entry procedures are flexible and easy, but they will get you in trouble flying internationally. You can use international procedures in the U.S., you should not use U.S. procedures internationally.
  • Course Reversals — The U.S. procedure turn is pretty much a holding pattern. Internationally, they are a completely different procedure and must be treated as such.
  • Speed — International speed rules differ from the U.S. but knowing three numbers keeps you within the limits anywhere in the world.
  • Bank Angle / Rate of Turn — The ICAO rules are just a little stricter.
  • Allowance for Known Wind — The U.S. allows for extraordinary drift corrections to compensate for wind in turns, ICAO rules do not.
  • EFC Timing — No differences here, but some techniques bear consideration.

Holding Instructions (U.S. Only)

The rules that follow appear to be unique to the U.S. FAA.

Standard Holding Pattern

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Figure: Standard Holding Pattern, from FAA-H-8083-15, page 10-10.

[FAA-H-8083-15, Figure 10.4] The standard pattern is a racetrack pattern with 180° turns to the right and one minute legs. Pilots are expected to compensate for the effect of a known wind except when turning and to adjust outbound timing so as to achieve a 1-minute (1-1/2 minutes above 14,000 feet) inbound leg.

[Aeronautical Information Manual §5-3-8 ¶j.1.] A "standard pattern" has right turns and a "nonstandard pattern" has left turns.

No Holding Instructions Given

[FAA-H-8083-15, page 10-11] If you arrive at your clearance limit before receiving clearance beyond the fix, ATC expects you to maintain the last assigned altitude and begin holding in accordance with the depicted holding pattern. If no holding pattern is depicted, you are expected to begin holding in a standard holding pattern on the course upon which you approached the fix.

[Aeronautical Information Manual §5-3-8.b.] If the holding pattern is charted and the controller doesn't issue complete holding instructions, the pilot is expected to hold as depicted on the appropriate chart.

Holding Instructions Given, Fix Undepicted

[FAA-H-8083-15, page 10-11, Aeronautical Information Manual §5-3-8.i.] Where a holding pattern is not depicted, the ATC clearance will specify the following:

  1. Direction of holding from the fix in terms of the eight cardinal compass points (i.e., N, NE, E, SE, etc.).
  2. Holding fix (the fix may be omitted if included at the beginning of the transmission as the clearance limit).
  3. Radial, course, bearing, airway, or route on which the aircraft is to hold.
  4. Leg length in miles if DME or area navigation (RNAV) is to be used (leg length will be specified in minutes on pilot request or if the controller considers it necessary).
  5. Direction of turn if left turns are to be made, the pilot requests or the controller considers it necessary.
  6. Time to expect-further-clearance (EFC) and any pertinent additional delay information.

Some pilots use what might be called "the wind arrow" method of drawing these undepicted holding patterns. I've always found it more useful to simply write the instructions down as given, but others swear by this method. You draw the pattern as the instructions are given. For example: (All diagrams from my notes.)

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"Hold northwest"

As soon as you hear this first part of the instruction, draw a wind arrow from the direction given. In this case, we draw an arrow FROM the northwest.

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"of the 30 DME fix, Austin VORTAC,"

If you are given a fix, you can place it at the arrowhead. You might also be given a navaid or a named fix, which can also be placed at the arrowhead. In this case, we place a 30 DME fix at the arrowhead.

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"130 radial,"

You will be typically given a radial, in which case the Navaid goes at the tail of the arrow. While not common, you might also be given a course, in which case the Navaid goes at the head of the arrow.

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"10-mile legs, left turns."

When given the length of the pattern you must still wait to hear if "left turns" is given. If it isn't then the turns will be to the right. In any case, you have to wait until the end of the instruction to make this determination. In this case, we draw the pattern to the left.

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Once we've drawn the pattern on the correct side, adding the leg distance comes next.

G450 Note

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Figure: G450 Holding Pattern Definition, from G450 Aircraft Operating Manual §2B-27-00, page 97.

One of the selling points for G450 Enhanced Navigation systems is that FMS holding patterns, en route and approach, are smarter. They are, we have been told, the published procedures. Well, that generally works but that isn't what the manual says. I have found errors over the years. If given "hold as published," I punch in the FMS holding pattern to get me started and then I hunt for the pattern first on the DU charts and then going through en route paper charts. If I can't find the published procedure, I ask. The G450 FMS is good, but it isn't perfect.

For a walk through on this, see G450 Hold as Published.

Entry Procedures

The U.S. and ICAO holding pattern sectors are identical, but the terminology is slightly different. The entry procedures under ICAO not as flexible as under U.S. rules and there are several special cases involving DME arcs and VOR radials.

Holding Pattern Shape and Terminology

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Figure: Entry sectors, from ICAO Doc 8168 Vol 1, Figure I-6-1-2.

  1. ICAO: Sector 1 (Parallel entry)
    U.S. FAA: Parallel
  2. ICAO: Sector 2 (Offset entry)
    U.S. FAA: Teardrop
  3. ICAO: Sector 3 (Direct entry)
    U.S. FAA: Direct

Sector 1 (Parallel) Entry

U.S. FAA [Aeronautical Information Manual §5-3-8 ¶3.(a)] When approaching the holding fix from anywhere in the parallel sector, turn to a heading to parallel the holding course outbound on the non holding side for approximately 1 minute, turn in the direction of the holding pattern through more than 180°, and return to the holding fix or intercept the holding course inbound.

ICAO [ICAO Doc 8168 Vol 1 §6 ¶ 1.4.4]

  1. at the fix, the aircraft is turned left onto an outbound heading for the appropriate period of time; then
  2. the aircraft is turned left onto the holding side to intercept the inbound track or to return to the fix; and then
  3. on second arrival over the holding fix, the aircraft is turned right to follow the holding pattern.

Sector 2 (Offset) Entry

U.S. FAA [Aeronautical Information Manual §5-3-8 ¶3.(b)] When approaching the holding fix from anywhere in the teardrop sector, fly to the fix, turn outbound using course guidance when available, or to a heading for a 30° teardrop entry within the pattern (on the holding side) for approximately 1 minute, then turn in the direction of the holding pattern to intercept the inbound holding course.

ICAO [ICAO Doc 8168 Vol 1 §6 ¶ 1.4.5]

  1. at the fix, the aircraft is turned onto a heading to make good a track making an angle of 30° from the reciprocal of the inbound track on the holding side; then
  2. the aircraft will fly outbound:
    1. for the appropriate period of time where timing is specified; or
    2. until the appropriate limiting DME distance is reached, where distance is specified. If a limiting radial is also specified, then the outbound distance is determined either by the limiting DME distance or the limiting radial, whichever comes first;
  3. the aircraft is turned right to intercept the inbound holding track; and
  4. on second arrival over the holding fix, the aircraft is turned right to follow the holding pattern.

Sector 3 (Direct) Entry

U.S. FAA [Aeronautical Information Manual §5-3-8 ¶3.(c)]When approaching the holding fix from anywhere in the direct entry sector, fly directly to the fix and turn to follow the holding pattern.

ICAO [ICAO Doc 8168 Vol 1 §6 ¶ 1.4.6]

Having reached the fix, the aircraft is turned right to follow the holding pattern.

DME Arc Entry Holding

ICAO [ICAO Doc 8168 Vol 1 §6 ¶ 1.4.7] At the fix, the aircraft shall enter the holding pattern in accordance with either Sector 1 or Sector 3 entry procedure.

Special Entry Procedure for VOR/DME Holding

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Figure: VOR/DME holding entry procedures, from ICAO Doc 8168 Vol 1 figure I-6-1-3.

ICAO [ICAO Doc 8168 Vol 1 §6 ¶ 1.4.8] Where a special entry procedure is used, the entry radial is clearly depicted.

Course Reversals versus Procedure Turns

The U.S. Procedure Turn can often be thought of as a holding pattern, in fact some are called "holding patterns in lieu of procedure turns." This is not true under ICAO: the entry procedures are different and the patterns themselves are varied and cannot normally be substituted one for the other.

These procedures are spelled out here: Course Reversals.

Speed

If you use 200 knots below 6,000 feet; 220 knots below 14,000 feet; and 240 knots above that, you will stay within PANS OPS 3 and 4 limitations and all other international holding speed limitations.

See Course Reversals for more information.

U.S. FAA

[FAA-H-8083-15, page 10-11] Reduce to holding speed when within 3 minutes of the holding fix. Maximum permitted speed is:

  • 200 KIAS (when below 6,000 feet),
  • 230 KIAS (when 6,001 - 14,000 feet),
  • 265 KIAS (when 14,001 feet and above).

[Aeronautical Information Manual §5-3-8.d.] When an aircraft is 3 minutes or less from a clearance limit and a clearance beyond the fix has not been received, the pilot is expected to start a speed reduction so that the aircraft will cross the fix, initially, at or below the maximum holding speed.

ICAO

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Figure: Holding speeds, from ICAO Doc 8168 Vol 1 Figure I-6-1-1.

[ICAO Doc 8168 Vol 1 §6 ¶ 1.3.1] Holding patterns shall be entered and flown at or below the airspeeds given:

Bank Angle/Rate of Turn

25 degrees of bank with your flight director works well everywhere.

U.S. FAA

[Aeronautical Information Manual §5-3-8 ¶ 6(b)] Make all turns during entry and while holding at:

  1. 3 degrees per second
  2. 30 degrees of bank
  3. 25 degrees bank provided a flight director system is used

Note: use whichever requires the least bank angle.

ICAO

[ICAO Doc 8168 Vol 1 §6 ¶ 1.3.2] All turns are to be made at a bank angle of 25° or at a rate of 3° per second, whichever requires the lesser bank.

Allowance for Known Wind

The U.S. allows "double drift" and "triple drift" techniques, the ICAO does not.

U.S. FAA

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Figure: Drift correction in a holding pattern, from FAA-H-8083-15 Figure 10-5.

[Aeronautical Information Manual §5-3-8 ¶ 6(c)] Compensate for wind effect primarily by drift correction on the inbound and outbound legs. When outbound, triple the inbound drift correction to avoid major turning adjustments.

These techniques are important when flying low speed aircraft where the relative velocity of the crosswind can be significant, but less so for a higher speed aircraft. Nonetheless, they remain valid techniques for any aircraft in U.S. airspace.

ICAO

[ICAO Doc 8168 Vol 1 §6 ¶ 1.3.3] All procedures depict tracks. Pilots should attempt to maintain the track by making allowance for known wind by applying corrections both to heading and timing. This should be done during entry and while flying in the holding pattern.

The ICAO does not specify double or triple drift techniques, but they don't specifically forbid them either. A triple drift, it should be noted, could place the airplane outside of protected airspace.

Timing

Start of Outbound Timing

U.S. FAA [Aeronautical Information Manual §5-3-8 ¶4.(b)] Outbound leg timing begins over/abeam the fix, whichever occurs later. If the abeam position cannot be determined, start timing when turn to outbound is completed.

ICAO [ICAO Doc 8168 Vol 1 §6 ¶ 1.3.4] Outbound timing begins over or abeam the fix, whichever occurs later. IF the abeam position cannot be determined, start timing when the turn to outbound is completed.

Timing

U.S. FAA [Aeronautical Information Manual §5-3-8 ¶4] The initial inbound leg should be flown for 1 minute (at or below 14,000 feet MSL) or 1-1/2 minutes (above 14,000 feet MSL). Timing for subsequent outbound legs should be adjusted, as necessary, to achieve proper inbound leg time.

ICAO [ICAO Doc 8168 Vol 1 §6 ¶ 1.4.9]

The still air timing for flying the outbound entry heading should not exceed:

  1. one minute if at or below 4,250 m (14,000 ft); or
  2. one and one-half minutes if above 4,250 m (14,000 ft).

Where DME is available, the length of the outbound leg may be specified in terms of distance instead of time.

Timing Technique

With slower aircraft you could vary your bank angle to produce standard rate and half standard rate turns to give known times for 360° circles, making time adjustments for an EFC easy. With higher speed aircraft you don't have that option, since a half-standard rate turn could place you outside protected airspace and a standard rate turn could exceed the 25° bank angle limit. Given these complications, you should do the following during your first trip around the holding pattern:

  • Enter the holding pattern at your planned holding speed.
  • Start timing as you begin your first 180° turn, stop timing as your roll out.
  • Double this time to establish your time to make a 360° turn.
  • You can adjust outbound leg timing to nail the EFC, example follows.
  • If you adjust your speed as the holding continues, time the next turn to establish a new 360° time.

EFC Example

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Figure: Holding pattern timing, from Eddie's notes.

Let's say you have an EFC of 1030Z and have entered the holding pattern at your desired speed. You time your first turn and come up with 1 minute, 15 seconds which means your 360° time is 2 minutes, 30 seconds.

On your next circuit you roll wings level outbound at 1015Z, 15 minutes to go. Since you know each circuit takes 4 minutes, 30 seconds (two 1-minute legs plus the 2 minute, 30 second 360°), you can kill the 15 minutes using two full circuits (9 minutes) and two partial circuits of 3 minutes each. How do you do that? A 360° circle takes 2 minutes, 30 seconds, so put a 15 second straight leg on each side:

  • 4:30 — First full circuit: 1 minute outbound, 1:15 turn, 1 minute inbound, 1:15 turn
  • 4:30 — Second full circuit: 1 minute outbound, 1:15 turn, 1 minute inbound, 1:15 turn
  • 3:00 — First partial circuit: 15 seconds outbound, 1:15 turn, 15 seconds inbound, 1:15 turn
  • 3:00 — Second partial circuit: 15 seconds outbound, 1:15 turn, 15 seconds inbound, 1:15 turn

Book Notes

Portions of this page can be found in the book Flight Lessons 1: Basic Flight, Chapter 17.

References

Aeronautical Information Manual

FAA-H-8083-15, Instrument Flying Handbook, U.S. Department of Transportation, Flight Standards Service, 2001.

Gulfstream G450 Aircraft Operating Manual, Revision 35, April 30, 2013.

ICAO Doc 8168 - Aircraft Operations - Vol I - Flight Procedures, Procedures for Air Navigation Services, International Civil Aviation Organization, 2006

Revision: 20131123
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