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Aircraft Holding Procedures

Introduction:

  • A holding procedure is a predetermined maneuver which keeps an aircraft within a specified airspace
  • These holding patterns are designed to keep the pilot in airspace that is reasonably protected
  • Performed for many reasons, including but not limited to:
    • Traffic congestion,
    • Waiting for an EFC time,
    • Poor weather, or
    • Unavailability of the runway
  • Can be accomplished at a NAVAID, a fix, or an intersection
    • A NAVAID (or Navigational Aid) is defined as any visual or electronic device airborne or on the surface which provides point-to-point guidance information or position data to aircraft in flight
    • A fix is defined as a geographical position determined by visual reference to the surface, by reference to one or more radio NAVAIDs, by celestial plotting, or by another navigational device
    • An intersection is defined by a point defined by any combination of courses, radials, or bearings of two or more navigational aids
  • Different types of holding patterns are established based on their purpose and phase of flight
Instrument Approach Procedures Holding Patterns
Figure 1: Instrument Approach Procedures Holding Patterns

Types of Holding Patterns

  • There are 3 types of holding, depicted in the instrument approach chart legend: [Figure 1]
    1. Holding in lieu of procedure turn:

      • Depicted as a solid bold line on an instrument approach
      • In fact, holding in lieu is not really a holding pattern, just a method by which to turn around (course reversal)
      • When used, you do not need to go outbound for the full distance but rather after 1 minute you should turn back in and shoot the approach
    2. Arrival pattern

      • Used to control the flow of traffic on an approach
      • Depicted as a thin solid line on instrument charts
      • Think of it as adding a delay to ensure the airport environment is clear
      • The arrival holding pattern is not authorized unless assigned by ATC
    3. Missed Approach

      • Visually depicts holding following the execution of a missed approach
      • Depicted as a dashed line on instrument approach procedure
      • This is considered teh "published missed"
      • Many times ATC will assign alternate instructions to facilitate traffic flow, especially during practice approaches

Holding Pattern Airspace Protection:

  • Holding areas must be designated as protected, i.e., free from obstacles
  • Holding pattern airspace protection is provided by controlling the pattern's size:
    • Holding Pattern Layout:

      • Standard Pattern: Right turns (Think that most people are right handed, making that standard)
      • Nonstandard Pattern: Left turns
      • Note that holding patterns depicted in the instrument approach plate legend show both left and right turns and are in no way an indication of standards
    • Holding Pattern Altitude

      • Clearly, obstacle protection increased with altitude
      • More importantly, altitude impacts airspeeds due to the operation (aircraft operating at higher altitudes fly faster)
      • The standard altitude blocks that we are concerned with are:
        • Surface to 6000 feet MSL
        • 6001 feet to 14,000 feet MSL
        • and 14,001 feet MSL and higher
    • Holding Pattern Airspeeds:

      • Holding is generally performed at max endurance, to conserve fuel
      • Holding patterns may be restricted to a maximum speed
        • ATC: "[Callsign] [holding instructions], maximum holding speed is [Speed in Knots]"
      • Holding speeds are based on turn radius to keep pilots clear of obstacles
        • The speed restriction is depicted in parenthesis inside the holding pattern on the chart: e.g., (175)
        • The aircraft should be at or below the maximum speed prior to initially crossing the holding fix to avoid exiting the protected airspace
        • Pilots unable to comply with the maximum airspeed restriction should notify ATC
      • The aircraft should be at or below the maximum speed prior to initially crossing the holding fix to avoid exiting the protected airspace
        • Below 6,000' MSL:

          200 KIAS
        • 6001' MSL to 14,000' MSL: 230 KIAS
          • Holding patterns from 6,001’ to 14,000’ may be restricted to a maximum airspeed of 210 KIAS
            • This nonstandard pattern will be depicted by an icon
        • 14,001' MSL and up:

          265 KIAS
          • Note that holding speeds change at 14,001 as well as the holding time (1.0 to 1.5 minutes)
        • USAF Airfields:

          310 KIAS
        • USN Airfields:

          230 KIAS
      • All helicopter/power lift aircraft holding on a “COPTER” instrument procedure is predicated on a minimum airspeed of 90 KIAS unless charted otherwise
      • When a climb-in hold is specified by a published procedure (i.e., "Climb-in holding pattern to depart XYZ VORTAC at or above 10,000." or "All aircraft climb-in TRUCK holding pattern to cross TRUCK Int at or above 11,500 before proceeding on course"), additional obstacle protection area has been provided to allow for greater airspeeds in the climb for those aircraft requiring them
        • A maximum airspeed of 310 KIAS is permitted in Climb-in-holding, unless a maximum holding airspeed is published, in which case that maximum airspeed is applicable
        • Where the holding pattern is restricted to a maximum airspeed of 175 KIAS, the 200 KIAS holding pattern template has been applied for published climb-in hold procedures for altitudes 6,000 feet and below and the 230 KIAS holding pattern template has been applied for altitudes above 6,000 feet
        • The airspeed limitations in 14 CFR Section 91.117, Aircraft Speed, still apply
  • The following phraseology may be used by an ATC to advise a pilot of the maximum holding airspeed for a holding pattern airspace area:
    • "[Callsign], [Holding instructions, when needed], maximum holding airspeed is [Speed in knots]"
  • Holding protected airspace is designed based in part on pilot compliance with the three recommended holding pattern entry procedures discussed below
    • Deviations from these recommendations, coupled with excessive airspeed crossing the holding fix, may in some cases result in the aircraft exceeding holding protected airspace

Holding Clearance:

  • When no delay is expected, the controller should issue a clearance beyond the fix as soon as possible and, whenever possible, at least 5 minutes before the aircraft reaches the clearance limit
  • If unable to issue a clearance to the destination an ATC clearance requiring an aircraft to hold at a fix where the pattern is not charted will include the following information:
  1. The direction to hold from the holding fix (i.e., N, NE, E, SE, etc.)
    • This is the general compass location in terms of the eight cardinal compass points
  2. The name of the holding fix
    • May be omitted if included at the beginning of the transmission as the clearance limit
  3. The radial, course, bearing, airway, or route on which the aircraft is to hold
  4. The leg length in miles if DME or RNAV is to be used
    • 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 (times are given in Zulu)
  • ATC: "Hold east of the Ormond VORTAC on the 090 radial, left turns, maintain 5,000,' expect further clearance 0+50"
  • At a minimum, the only information you need is the location, the radial, and the EFC time
  • When charted, the controller may omit all holding instructions, except the charted holding direction and the statement "as published"
    • ATC: "Hold east as published"
  • Controllers shall always issue complete holding instructions when pilots request them
  • Request EFC time if not automatically provided by ATC
Holding Entries Overview
Figure 1: Holding Pattern Entry Procedures

Holding Orbits:

  • Holding consists of several orbits in an oval shaped pattern
  • As we discuss below, the orbit is determined based on a location and timing/distance
  • The first orbit is the entry orbit which expeditiously establishes the aircraft inbound on the holding courses
  • The second orbit is the no-wind orbit which sets the baseline from which all corrections can then be made
  • The last orbit flown is the correction orbit which updates and refines the wind corrections
  • Entry Orbit:

    • In order to determine the type of entry you can utilize many different methods:
      • Pencil Method:

        • If instructed to perform left turns:
          • Raise the left side of the pencil 20° and see where the reciprocal course lies
        • If instructed to perform right turns:
          • Raise the right side of the pencil 20° and see where the reciprocal course lies
    • There will be cases in which the reciprocal will fall on, or very close to (±5°) a sector boundary in which case the entry procedures for either section are acceptable
    • Entry Procedures:

      • Direct Entry:

        • When approaching the holding fix from anywhere in sector (c), the direct entry procedure would be to fly directly to the fix and turn to follow the holding pattern [Figure 1]
      • Parallel Entry:

        • When approaching the holding fix from anywhere in sector (a), the parallel entry procedure would be to turn to a heading to parallel the holding course outbound on the non holding side for one minute, turn in the direction of the holding pattern through more than 180 degrees, and return to the holding fix or intercept the holding course inbound [Figure 1]
          • Right Turns: first turn left, then left, then right
          • Left Turns: first turn right, then right, then left
      • Teardrop Entry:

        • When approaching the holding fix from anywhere in sector (b), the teardrop entry procedure would be to fly to the fix, turn outbound to a heading for a 30 degree teardrop entry within the pattern (on the holding side) for a period of one minute, then turn in the direction of the holding pattern to intercept the inbound holding course [Figure 1]
          • Remember Left Add Right Subtract, or LARS for short
            • L+30
            • R-30
        • While other entry procedures may enable the aircraft to enter the holding pattern and remain within protected airspace, the parallel, teardrop and direct entries are the procedures for entry and holding recommended by the FAA, and were derived as part of the development of the size and shape of the obstacle protection areas for holding
  • No-wind Orbit:

    • The no wind orbit begins the second time the aircraft crosses the station, which leads to determining the initial corrections to make for existing winds
    • As the name suggests, this orbit is flown as if there were no-wind for which to compensate
      • If this were true, you would (1) roll out of your inbound turn on the holding course and (2) inbound timing to the holding fix, if required, would equal the amount of time outbound
    • It is important that the execution of the holding pattern are made as precisely as possible in order to identify initial corrections
  • Correction Orbit:

    • The third and subsequent orbits in holding are called correction orbits
    • They are flown by applying the correction factors determined on the previous orbit to the outbound leg of the holding pattern
    • Adjust the heading by the correction factor determined on the no-wind orbit
      • TAIL-RADIAL-WIND
    • Confirm EFC 5 minutes before it is reached
    • Be as exact on corrections as possible

    • VOR CORRECTION FACTOR:
      • Apply full correction outbound (if off 10°, apply 10°)
      • Apply 1/3 of the wind correction inbound
    • 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; e.g., if correcting left by 8 degrees when inbound, correct right by 24 degrees when outbound
    • TACAN CORRECTION FACTOR:
      • Use full correction into the wind on the outbound leg
      • Use half correction into the wind on the inbound leg

      • DME of longest leg X degrees off = correction factor you will use
    • 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; e.g., if correcting left by 8 degrees when inbound, correct right by 24° when outbound

Timing:

  • Some aircraft will have their own timers but you can just as easily bring your own Flight Timer/watch to mount to the aircraft or kneeboard
  • Inbound Leg:

    • At or below 14,000' MSL, legs should be timed to equal 1 minute
    • Above 14,000' MSL, legs should be timed to equal 1 and 1/2 minutes
    • Timing inbound is measured from the point that the aircraft is wings level, inbound to the holding fix, to the time the aircraft crosses the holding fix
  • The outbound leg:

    • time will be adjusted to achieve the correct inbound timing
    • 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
      • Abeam is when the needle drops below the 90° benchmark in the HSI, not the TO/FROM flip
    • The initial outbound leg should be flown for 1 minute or 1 1/2 minutes (appropriate to altitude)
    • Timing for subsequent outbound legs should be adjusted, as necessary, to achieve proper inbound leg time
  • Pilots may use any navigational means available; i.e., DME, RNAV, etc., to ensure the appropriate inbound leg times
  • Timing is generally associated with VOR holding, but some TACAN holds may require timing if no DME specified
NOTE:
In order to remember this rule, remember that no one will make you hold at 14,001' but rather 14,000 or 15,000 most likely. The 1.5 minute leg comes to play at 15k 10% RULE: 15 = 1.5 min

Practice:

  • Request a few turns in holding when you want practice
  • If you request 1 turn in holding, your entry doesn't count
    • In other words when you enter holding at first and initially pass the fix (even if a direct entry), then that orbit doesn't count
    • 1 full round in the pattern is the 1 you requested

Procedure:

WARNING:
All procedures here are GENERALIZED for learning.
Fly the maneuver in accordance with the Pilot Operating Handbook (POH)
and/or current Standard Operating Procedures (SOPs)


  1. Copy and read back holding clearance
  2. Determine the holding course and reciprocal of the holding course (radial)
    • The holding course is the inbound course to the holding fix
    • The reciprocal of the holding course (radial) is used to determine the direction of entry turn. When the holding fix is a NAVAID, the reciprocal will be the same as the radial
  3. Determine the direction of the entry
  4. Tune and ID appropriate stations
  5. Proceed direct the holding fix
  6. Start speed reduction when 3 minutes or less from the holding fix
    • 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 airspeed
  7. Enter orbit: perform the Ts
    • TIME: note the time of entry
    • TURN: turn as determined to execute entry with whichever of the below require the least bank angle:
      • All turns are done at: 3 per second; or 30° angle of bank; or 25° angle of bank provided a flight director system is used, whichever requires the least bank angle
    • TIME: start timing when wings level or abeam the station (head of the needle on or below the 90), whichever occurs last
    • TYPE: put the holding course in the MFD
    • TALK: give the voice report and check EFC
    • Pilot: "[Place], [Callsign], holding at [Location], [Time], [Altitude]"
  8. After completion of outbound timing or at the specified DME, turn to intercept the holding course inbound
  9. During the last half of the turn, check the position of the head of the needle relative to the holding course
    • The head of the needle should always be in a place to fall onto the course when you're checking your turn inbound
    • If not on course, stop the turn with a double the angle intercept for VOR holding
    • When turning to intercept the inbound course in TACAN holding, an intercept greater than double the angle will be required
    • Begin timing once wings level inbound to the fix or station
    • This is to compensate for greater spacing between radials when holding away from the station. In TACAN holding a 30 to 45° angle of intercept will establish the aircraft on the inbound course
    • Once established on course, commence tracking inbound to the holding fix
    • It is critical to establish the aircraft on course prior to crossing the holding fix
  10. Continue to the station and initiate your turn in the direction of holding to begin the no wind orbit
  11. Roll out of the turn on the outbound heading parallel to the holding course
  12. Start the outbound leg timing, if required, when wings are level or abeam the station
  13. At the completion of the outbound leg timing or at the specified DME, turn toward the holding radial to intercept the holding course
  14. As you roll wings level, check the position of the head of the needle to the holding course
    • If they differ, note the number of degrees difference
    • This will determine the amount of heading correction to use on the outbound leg of your correction orbit. Do this as quickly as possible
  15. If you had to set an intercept when you turned inbound, there are winds to correct for
    • TAIL - RADIAL - WIND
    • When checking the wind, resist the temptation to check wind from the head of the needle because it will be on the top of the RMI where you are looking, this will give you opposite winds causing error
  16. Establish the aircraft on the holding course and track inbound to the holding fix
  17. At station passage, note how much time has elapsed on the inbound leg
    • Determine the difference between the elapsed time and the desired inbound timing
    • You will use this correction factor for timing on the outbound leg of your correction orbit

AFTER EVERY ORBIT DO THE Ts. IF IT DOESN'T APPLY, IGNORE IT BUT TIME IS ALWAYS AN EFC CHECK TO GET AN UPDATE WITHIN 5 MINUTES OF THE REPORTED EFC TIME

  • Pilots should report to ATC the time and altitude/flight level at which the aircraft reaches the clearance limit and report leaving the clearance limit
    • In the event of two-way communications failure, pilots are required to comply with 14 CFR Section 91.185
  • When holding at a VOR station, pilots should begin the turn to the outbound leg at the time of the first complete reversal of the to/from indicator
  • Patterns at the most generally used holding fixes are depicted (charted) on U.S. Government or commercially produced (meeting FAA requirements) Low or High Altitude En Route, Area, Departure Procedure, and STAR Charts
    • Pilots are expected to hold in the pattern depicted unless specifically advised otherwise by ATC
    • Holding patterns that protect for a maximum holding airspeed other than the standard may be depicted by an icon, unless otherwise depicted
    • The icon is a standard holding pattern symbol (racetrack) with the airspeed restriction shown in the center
    • In other cases, the airspeed restriction will be depicted next to the standard holding pattern symbol
  • UHF: "[Place], [Callsign], departing holding"

  • Airspeed, when departing holding for an approach, is pilot's discretion of either slow or normal cruise
  • Advise ATC immediately what increased airspeed is necessary, if any, due to turbulence, icing, etc., or if unable to accomplish any part of the holding procedures. When such higher speeds become no longer necessary, operate according to the appropriate published holding speed and notify ATC

  • NOTE:
    Do not hold for an approach you cannot legally execute. If current weather at destination is less than published weather minimums for any suitable approach, request clearance to your alternate airport

    Procedure: (Two Nav Receivers)

    1. Copy and read back holding instructions
    2. Determine the direction of heading to turn to for the entry orbit
      • Use the sector method
    3. Using two NAVAIDs intersection procedures, ensure they are tuned and set, toggled and twisted
      • The primary NAVAID should be tuned into the fix from which the holding radial is off of
      • The secondary NAVAID should be tuned into the identifying station
    4. When 10° of the intersection, be sure you have switched to the primary NAVAID toggle (be it VOR or TACAN as set up)
    5. At the intersection, commence the Ts as with normal holding

    NOTE:
    In station side holding, inbound to the fix means away from the station. You will be using the TAIL of the needle to fly inbound

    • Once established, inbound switch the toggle and twist in the radial use to identify the intersection
      • Continue following the inbound radial on the HSI
      • This should be accomplished no later than 30 seconds after wings level inbound
    • Commence a no-wind orbit as with any holding and once timing starts, twist in the holding course
    • Continue to hold as normal

    Procedure: (One Nav Receiver)

    • Similar to using two NAVAIDs however, in this case, you will be using a single receiver to monitor both the primary and secondary NAVAIDs
    1. 3 to 5 minutes prior to reaching the holding intersection, ensure the secondary NAVAID is tuned and identified to check your position
      • Keep the volume low and constantly IDing to save time in the pattern
    2. Determine the entry
    3. At the intersection, perform the Ts
    4. When timing outbound, tune and ID the primary NAVAID and toggle/twist the inbound course
    5. At the completion of outbound timing, turn in and no later than 30 seconds after rolling wings level
      • Get back on the radial
      • Tune, ID, toggle, and twist the secondary NAVAID to identify the intersection
    6. Commence a no-wind orbit the same way
    7. Commence a correction orbit the same way
      • Corrections will be done using the TACAN holding procedures, using a correction factor; however, due to airspeed, possibly changing the length of legs, be conservative

    Departing Holding:

    • When holding at a fix and instructions are received specifying the time of departure from the fix, the pilot should adjust the aircraft’s flight path within the limits of the established holding pattern in order to leave the fix at the exact time specified
    • After departing the holding fix, normal speed is to be resumed with respect to other governing speed requirements, such as terminal area speed limits, specific ATC requests, etc.
    • Where the fix is associated with an instrument approach and timed approaches are in effect, a procedure turn must not be executed unless the pilot advises ATC, since aircraft holding are expected to proceed inbound on final approach directly from the holding pattern when approach clearance is received

    Radar surveillance of outer fix holding pattern airspace areas:

    • Whenever aircraft are holding at an outer fix, ATC will usually provide radar surveillance of the outer fix holding pattern airspace area, or any portion of it, if it is shown on the controller’s radar scope
    • The controller will attempt to detect any holding aircraft that stray outside the holding pattern airspace area and will assist any detected aircraft to return to the assigned airspace area
      • Many factors could prevent ATC from providing this additional service, such as workload, number of targets, precipitation, ground clutter, and radar system capability. These circumstances may make it unfeasible to maintain radar identification of aircraft to detect aircraft straying from the holding pattern. The provision of this service depends entirely upon whether controllers believe they are in a position to provide it and does not relieve a pilot of their responsibility to adhere to an accepted ATC clearance
    • If an aircraft is established in a published holding pattern at an assigned altitude above the published minimum holding altitude and subsequently cleared for the approach, the pilot may descend to the published minimum holding altitude. The holding pattern would only be a segment of the IAP if it is published on the instrument procedure chart and is used in lieu of a procedure turn

    Intersection holding steps that must be repeated:


    Dual Nav Single Nav
    Time Yes Yes
    Tune No Yes
    ID No Yes
    Toggle Yes No
    Twist Yes Yes


    Holding Entries Overview
    Figure 2: Holding Entries Overview

    Distance Measuring Equipment (DME)/GPS Along-Track Distance (ATD):

    • DME/GPS holding is subject to the same entry and holding procedures except that distances (nautical miles) are used in lieu of time values
    • The outbound course of the DME/GPS holding pattern is called the outbound leg of the pattern
    • The controller or the instrument approach procedure chart will specify the length of the outbound leg
    • The end of the outbound leg is determined by the DME or ATD readout
    • The holding fix on conventional procedures, or controller defined holding based on a conventional navigation aid with DME, is a specified course or radial and distances are from the DME station for both the inbound and outbound ends of the holding pattern
    • When flying published GPS overlay or stand alone procedures with distance specified, the holding fix will be a waypoint in the database and the end of the outbound leg will be determined by the ATD
    • Some GPS overlay and early stand alone procedures may have timing specified
    • See Global Positioning System (GPS) page, for requirements and restriction on using GPS for IFR operations
    • When the inbound course is toward the NAVAID, the fix distance is 10 NM, and the leg length is 5 NM, then the end of the outbound leg will be reached when the DME/ATD reads 15 NM [Figure 2]
    • When the inbound course is away from the NAVAID and the fix distance is 28 NM, and the leg length is 8 NM, then the end of the outbound leg will be reached when the DME/ATD reads 20 NM [Figure 3]
    • The inbound course is always toward the waypoint and the ATD is zero at the waypoint. The end of the outbound leg of the holding pattern is reached when the ATD reads the specified distance [Figure 4]
    Inbound Toward NAVAID
    Figure 2: Inbound Toward NAVAID
    Inbound Leg Away from NAVAID
    Figure 3: Inbound Leg Away from NAVAID
    GPS/RNAV Holding
    Figure 4: GPS/RNAV Holding
    GPS/RNAV Holding
    Figure 4: Difference Between DME Distance From NAVAID & RNAV Computed Distance From NAVAID

    Use of RNAV Distance in lieu of DME Distance:

    • Substitution of RNAV computed distance to or from a NAVAID in place of DME distance is permitted when holding. However, the actual holding location and pattern flown will be further from the NAVAID than designed due to the lack of slant range in the position solution (see FIG 5−3−7). This may result in a slight difference between RNAV distance readout in reference to the NAVAID and the DME readout, especially at higher altitudes. When used solely for DME substitution, the difference between RNAV distance to/from a fix and DME slant range distance can be considered negligible and no pilot action is required. REFERENCE− AIM Paragraph 1−2−3, Use of Suitable Area Navigation (RNAV) Systems on Conventional Procedures and Routes

    Use of RNAV Guidance and Holding:

    • RNAV systems, including multi-sensor Flight Management Systems (FMS) and stand-alone GPS receivers, may be used to furnish lateral guidance when executing a hold. The manner in which holding is implemented in an RNAV system varies widely between aircraft and RNAV system manufacturers. Holding pattern data may be extracted from the RNAV database for published holds or may be manually entered for ad-hoc ATC−assigned holds. Pilots are expected to be familiar with the capabilities and limitations of the specific RNAV system used for holding
      • All holding, including holding defined on an RNAV or RNP procedure, is based on the conventional NAVAID holding design criteria, including the holding protected airspace construction. There are differences between the holding entry and flight track assumed in conventional holding pattern design and the entry and track that may be flown when RNAV guidance is used to execute holding. Individually, these differences may not affect the ability of the aircraft to remain within holding pattern protected airspace. However, cumulatively, they can result in deviations sufficient to result in excursions up to limits of the holding pattern protected airspace, and in some circumstances beyond protected airspace. The following difference and considerations apply when an RNAV system furnishes the lateral guidance used to fly a holding pattern:
        • Many systems use ground track angle instead of heading to select the entry method. While the holding pattern design allows a 5 degree tolerance, this may result in an unexpected entry when the winds induce a large drift angle
        • The holding protected airspace is based on the assumption that the aircraft will fly-over the holding fix upon initial entry. RNAV systems may execute a "fly-by" turn when approaching the holding fix prior to entry. A "fly-by" turn during a direct entry from the holding pattern side of holding course may result in excursions beyond protected airspace, especially as the intercept angle and ground speed increase
        • During holding, RNAV systems furnish lateral steering guidance using either a constant bank or constant radius to achieve the desired inbound and outbound turns. An aircraft’s flight guidance system may use reduced bank angles for all turns including turns in holding, especially at higher altitudes, that may result in exceeding holding protected airspace. Use of a shallower bank angle will expand both the width and length of the aircraft track, especially as wind speed increases. If the flight guidance system’s bank angle limit feature is pilot-selectable, a minimum 25 degree bank angle should be selected regardless of altitude unless aircraft operating limitations specify otherwise and the pilot advises ATC
        • Where a holding distance is published, the turn from the outbound leg begins at the published distance from the holding fix, thus establishing the design turn point required to remain within protected airspace. RNAV systems apply a database coded or pilot-entered leg distance as a maximum length of the inbound leg to the holding fix. The RNAV system then calculates a turn point from the outbound leg required to achieve this inbound leg length. This often results in an RNAV−calculated turn point on the outbound leg beyond the design turn point. (See FIG 5−3−8). With a strong headwind against the outbound leg, RNAV systems may fly up to and possibly beyond the limits of protected airspace before turning inbound. (See FIG 5−3−9.) This is especially true at higher altitudes where wind speeds are greater and ground speed results in a wider holding pattern
        • Some RNAV systems compute the holding pattern based on the aircraft’s altitude and speed at a point prior to entering the hold. If the indicated airspeed is not reduced to comply with the maximum holding speed before this point, the computed pattern may exceed the protected airspace. Loading or executing a holding pattern may result in the speed and time limits applicable to the aircraft’s current altitude being used to define the holding pattern for RNAV lateral guidance. This may result in an incorrect hold being flown by the RNAV system. For example, entering or executing the holding pattern above 14,000 feet when intending to hold below 14,000 feet may result in applying 1 ½ minute timing below 14,000 feet
          • NOTE− Some systems permit the pilot to modify leg time of holding patterns defined in the navigation database; for example, a hold-in-lieu of procedure turn. In most RNAV systems, the holding pattern time remains at the pilot-modified time and will not revert back to the coded time if the aircraft descends to a lower altitude where a shorter time interval applies
      • RNAV systems are not able to alert the pilot for excursions outside of holding pattern protected airspace since the dimensions of this airspace are not included in the navigation database. In addition, the dimensions of holding pattern protected airspace vary with altitude for a charted holding pattern, even when the hold is used for the same application. Close adherence to the pilot actions described in this section reduce the likelihood of exceeding the boundary of holding pattern protected airspace when using RNAV lateral guidance to conduct holding
      • Holding patterns may be stored in the RNAV system’s navigation database and include coding with parameters defining how the RNAV system will conduct the hold. For example, coding will determine whether holding is conducted to manual termination (HM), continued holding until the aircraft reaches a specified altitude (HA), or holding is conducted until the holding fix is crossed the first time after entry (HF). Some systems do not store all holding patterns, and may only store patterns associated with missed approaches and hold-in-lieu of procedure turn (HILPT). Some store all holding as standard patterns and require pilot action to conduct non-standard holding (left turns)
        • Pilots are cautioned that multiple holding patterns may be established at the same fix. These holding patterns may differ in respect to turn directions and leg lengths depending on their application as an en route holding pattern, a holding pattern charted on a SID or STAR, or when used on an instrument approach procedure. Many RNAV systems limit the database coding at a particular fix to a single holding pattern definition. Pilots extracting the holding pattern from the navigation database are responsible for confirming that the holding pattern conforms to the assigned charted holding pattern in terms of turn direction, speed limit, timing, and distance
        • If ATC assigns holding that is not charted, then the pilot is responsible for programming the RNAV system with the assigned holding course, turn direction, speed limit, leg length, or leg time
        • Changes made after the initial execution may not apply until the next circuit of the holding pattern if the aircraft is in close proximity to the holding fix
    NOTE:
    In order to identify an intersection formed by two or more radials, you must use the radials that have "arrows" associated with them from the appropriate NAVAID

    • Treat intersection holding as if it were a VOR
    • Primary NAVAID:
      • The NAVAID and radial from that NAVAID upon which the holding pattern is oriented
    • Secondary NAVAID:
      • The NAVAID and radial from that NAVAID which defines the holding fix (intersection) on the primary radial

    • When flying a point-to-point to an intersection you will likely hit one radial before the other; just keep the same holding entry procedures in mind and apply them here
    • When holding at a VOR station, the reciprocal of the holding course is ALWAYS the same as the radial
    • At an intersection, however, this will only be true when the holding pattern is oriented so that the inbound leg is toward the station
    • Holding is always INBOUND to a FIX
    • When that fix is an intersection, the inbound holding course could possibly be away from the station

    Airman Certification Standards:

    Reverse Sensing:

    • Reverse sensing is a conditions where the navigation instrument indicates the inverse of what it should
    • To avoid reverse sensing:
      • Intercept and track inbound TO
      • Intercept and track outbound FROM

    VFR Holding:

    • While rare, there is such a thing as VFR Holding
    • Usually it is just an ATC instruction to remain clear of a particular area or airspace, or to circle a known point
    • Sometimes it is a little more in-depth and part of local traffic flow such as for an event; for example, Oshkosh

    Responsibilities:

    • Whenever an aircraft is cleared to a fix other than the destination airport and delay is expected, it is the responsibility of ATC to issue complete holding instructions (unless the pattern is charted), an EFC time and best estimate of any additional en route/terminal delay
      • Only those holding patterns depicted on U.S. government or commercially produced (meeting FAA requirements) low/high altitude en route, and area or STAR charts should be used
    • 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
      • When the pattern is charted on the assigned procedure or route being flown, ATC may omit all holding instructions except the charted holding direction and the statement AS PUBLISHED; for example, HOLD EAST AS PUBLISHED
      • ATC must always issue complete holding instructions when pilots request them
    • If no holding pattern is charted and holding instructions have not been issued, the pilot should ask ATC for holding instructions prior to reaching the fix
      • This procedure will eliminate the possibility of an aircraft entering a holding pattern other than that desired by ATC
      • If unable to obtain holding instructions prior to reaching the fix (due to frequency congestion, stuck microphone, etc.), then enter a standard pattern on the course on which the aircraft approached the fix and request further clearance as soon as possible
      • In this event, the altitude/flight level of the aircraft at the clearance limit will be protected so that separation will be provided as required
    • Pilot Actions:
      • Start speed reduction when 3 minutes or less from the holding fix. Cross the holding fix, initially, at or below the maximum holding airspeed
      • Make all turns during entry and while holding at:
        • 3 degrees per second; or
        • 30 degree bank angle; or
        • 25 degree bank provided a flight director system is used
          • NOTE−Use whichever requires the least bank angle
      • 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; e.g., if correcting left by 8 degrees when inbound, correct right by 24 degrees when outbound
      • Determine entry turn from aircraft heading upon arrival at the holding fix; +/−5 degrees in heading is considered to be within allowable good operating limits for determining entry
      • Advise ATC immediately what increased airspeed is necessary, if any, due to turbulence, icing, etc., or if unable to accomplish any part of the holding procedures. When such higher speeds become no longer necessary, operate according to the appropriate published holding speed and notify ATC
    a. 8. Pilot Action. The following actions are recommended to ensure that the aircraft remains within holding protected airspace when holding is performed using either conventional NAVAID guidance or when using RNAV lateral guidance i. (a) Speed. When ATC furnishes advance notice of holding, start speed reduction to be at or below the maximum holding speed allowed at least 3 minutes prior to crossing the holding fix. If advance notice by ATC is not provided, begin speed reduction as expeditiously as practical. It is acceptable to allow RNAV systems to determine an appropriate deceleration point prior to the holding fix and to manage the speed reduction to the RNAV computed holding speed. If the pilot does not permit the RNAV system to manage the deceleration from the computed point, the actual hold pattern size at holding entry may differ from the holding pattern size computed by the RNAV system 1. (1) Aircraft are expected to enter holding at or below the maximum holding speed established in paragraph 5−3−8 j 2(a) or the charted maximum holding speed a. [a] All fixed wing aircraft conducting holding should fly at speeds at or above 90 KIAS to minimize the influence of wind drift. b. [b] When RNAV lateral guidance is used in fixed wing airplanes, it is desirable to enter and conduct holding at the lowest practical airspeed consistent with the airplane’s recommended holding speed to address the cumulative errors associated with RNAV holding and increase the probability of remaining within protected airspace. It is acceptable to allow RNAV systems to determine a recommended holding speed that is at or below the maximum holding speed c. [c] Helicopter holding is based on a minimum airspeed of 90 KIAS 2. (2) Advise ATC immediately if unable to comply with the maximum holding airspeed and request an alternate clearance. NOTE− Speeds above the maximum or published holding speed may be necessary due to turbulence, icing, etc. Exceeding maximum holding airspeed may result in aircraft excursions beyond the holding pattern protected airspace. In a non−radar environment, the pilot should advise ATC that they cannot accept the assigned hold 3. (3) Ensure the RNAV system applies the proper time and speed restrictions to a holding pattern. This is especially critical when climbing or descending to a holding pattern altitude where time and speed restrictions are different than at the present aircraft altitude ii. (b) Bank Angle. For holding not involving the use of RNAV lateral guidance, make all turns during entry and while holding at: 1. (1) 3 degrees per second, or 2. (2) 30 degree bank angle, or 3. (3) 25 degree bank angle, provided a flight director system is used. NOTE− Use whichever requires the least bank angle. 4. (4) When using RNAV lateral guidance to conduct holding, it is acceptable to permit the RNAV system to calculate the appropriate bank angle for the outbound and inbound turns. Do not use flight guidance system bank angle limiting functions of less than 25 degrees unless the feature is not pilot−selectable, required by the aircraft limitations, or its use is necessary to comply with the aircraft’s minimum maneuvering speed margins. If the bank angle must be limited to less than 25 degrees, advise ATC that additional area for holding is required. iii. (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; for example, if correcting left by 8 degrees when inbound, correct right by 24 degrees when outbound. iv. (d) Determine entry turn from aircraft heading upon arrival at the holding fix; +/− 5 degrees in heading is considered to be within allowable good operating limits for determining entry. When using RNAV lateral guidance for holding, it is permissible to allow the system to compute the holding entry. v. (e) RNAV lateral guidance may execute a fly−by turn beginning at an excessively large distance from the holding fix. Reducing speed to the maximum holding speed at least 3 minutes prior to reaching the holding fix and using the recommended 25 degree bank angle will reduce potential excursions beyond protected airspace. vi. (f) When RNAV guidance is used for holding, pilots should be prepared to intervene if the turn from outbound leg to the inbound leg does not begin within a reasonable distance of the charted leg length, especially when holding is used as a course reversal HILPT. Pilot intervention is not required when holding in an ATC−assigned holding pattern that is not charted. However, notify ATC when the outbound leg length becomes excessive when RNAV guidance is used for holding. b. k. When holding at a fix and instructions are received specifying the time of departure from the fix, the pilot should adjust the aircraft’s flight path within the limits of the established holding pattern in order to leave the fix at the exact time specified. After departing the holding fix, normal speed is to be resumed with respect to other governing speed requirements, such as terminal area speed limits, specific ATC requests, etc. Where the fix is associated with an instrument approach and timed approaches are in effect, a procedure turn must not be executed unless the pilot advises ATC, since aircraft holding are expected to proceed inbound on final approach directly from the holding pattern when approach clearance is received. c. l. Radar surveillance of holding pattern airspace areas i. 1. Whenever aircraft are holding, ATC will usually provide radar surveillance of the holding airspace on the controller’s radar display ii. 2. The controller will attempt to detect any holding aircraft that stray outside the holding airspace and will assist any detected aircraft to return to the assigned airspace. NOTE− Many factors could prevent ATC from providing this additional service, such as workload, number of targets, precipitation, ground clutter, and radar system capability. These circumstances may make it unfeasible to maintain radar identification of aircraft to detect aircraft straying from the holding pattern. The provision of this service depends entirely upon whether controllers believe they are in a position to provide it and does not relieve a pilot of their responsibility to adhere to an accepted ATC clearance iii. 3. ATC is responsible for traffic and obstruction separation when they have assigned holding that is not associated with a published (charted) holding pattern. Altitudes assigned will be at or above the minimum vectoring or minimum IFR altitude. iv. 4. If an aircraft is established in a published holding pattern at an assigned altitude above the published minimum holding altitude and subsequently cleared for the approach, the pilot may descend to the published minimum holding altitude. The holding pattern would only be a segment of the IAP if it is published on the instrument procedure chart and is used in lieu of a procedure turn.

    Conclusion:

    • If cleared for the approach when in holding and flying outbound, you do not have to fly outbound any longer, turn in and shoot the approach
    • Holding has a lot of variables which must be understood to be flown properly
      • Remember, there may be aircraft stacked above or below you in holding
      • It is therefore key that task saturation does not allow for altitude deviations while flying set airspeeds and controlling timing
    • For those holding patterns where there are no published minimum holding altitudes, the pilot, upon receiving an approach clearance, must maintain the last assigned altitude until leaving the holding pattern and established on the inbound course. Thereafter, the published minimum altitude of the route segment being flown will apply. It is expected that the pilot will be assigned a holding altitude that will permit a normal descent on the inbound course
    • Self test: http://www.lunabase.org/~faber/Vault/software/hold_quiz/
    • Picturing holding patterns makes it a lot easier, draw if necessary
    • If holding should not be accomplished (i.e., during an emergency), ask for radar vectors to acheive a similiar end-state to holding

    References: