APPENDIX: Holding I
What is a Standard Holding Pattern?
A standard holding pattern is flown by following a specified holding course to a fix, turn 180° to the right, paralleling the course outbound until reaching your timing or appropriate DME, then turning right to intercept the holding course or proceeding direct to the holding fix (initial turn only). Turns are 30° of bank or standard rate turns whichever is less. Remember, you are considered established in holding as soon as you cross the fix the first time.
What speed do we hold at?
The maximum speed we can hold at is specified in AIM and it’s based on the TERPS airspace:
All aircraft:
Minimum Holding Altitude – 6000 ft: 200 KIAS
6,001 ft – 14,000 ft: 230 KIAS
14,001 and above: 265 KIAS
Exceptions:
- Holding patterns from 6001 ft to 14,000 ft may be restricted to a maximum airspeed of 210 KIAS. This nonstandard pattern will be depicted by an icon.
- Holding patterns at all altitudes may be restricted to a maximum airspeed of 175 KIAS. This non-standard pattern will be depicted by an icon.
- Holding patterns at USAF airfields only- 310 KIAS maximum, unless otherwise depicted
- Holding patterns at NAVY fields only – 230 KIAS maximum, unless otherwise depicted.
Published Holding Pattern ROEs
ATC holding instructions may be detailed or just "hold as published." 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.* (only those holding pattern depicted on U.S. Government Low/Hi altitude en-route, Area/Terminal or STAR charts should be used) ref GP, AIM and FAAO 7110.65H. If there is any question or confusion, ask the controller for more information.
Random Holding Instructions
Random holding instructions are always given in the same manner.
- Direction of holding from the fix in terms of the eight cardinal compass points (i.e. N, NE, E, SE)
- Holding fix (the fix may be omitted if included at the beginning of the transmission as the clearance limit)
- Radials, course, bearing airway or route on which the aircraft is to hold
- Leg length in miles if DME or RNAV is to be used (leg length will be specified in minutes on pilot request or if the controllerconsiders it necessary)
- Direction of turn if left turns are to be made, the pilot requests or if the controller considers it necessary)
- Time to expect further clearance and any pertinent additional delay information
Example: Hold southwest of the 40DME fix, CAB TACAN, 045° radial, 10 mile legs.
Two common methods of drawing the holding pattern:
The Wind Arrow method. It involves drawing an arrow from the assigned holding direction. The arrow head is the holding fix. Leg length is marked by a limit line, either in DME or time. Complete pattern by turning in the assigned holding direction. Don't forget to place NAVAID for proper orientation.
The Cross or Quadrant method. The NAVAID is always in the center of the cross. Start by drawing the holding course from the NAVAID based on direction of holding or radial. Fill in the holding pattern fix, leg length, and direction of holding. Now you have a drawing of the holding pattern and a map to facilitate your fixtofix.
Holding Pattern Entry
AFI 11-217
Within 70°. If the inbound holding course is located within 70° of the aircraft heading, enter the holding pattern by turning in the direction of holding: standard turn right: nonstandard pattern, turn left.
Not within 70°. If the inbound holding course is not within 70° of the aircraft heading, turn outbound in the shorter direction to parallel or attempt to intercept the holding course.
Conveniently Aligned for a Teardrop (definition) Although “conveniently aligned” may vary with the aircraft and situation, 45 is easy to remember and use. If your heading indicator has 45 indexes, the following is a good technique to use if you choose to fly a teardrop entry. If the teardrop course lies between the top 45 indexes, at holding fix passage, turn to intercept the teardrop course.
Conveniently aligned technique is within 45° of the teardrop course you’ve calculated. In other words, a 90° entry cone centered on the teardrop heading. Compute the teardrop track using (TR X 120/Leg Length = Offset Angle). Where course guidance is available, (holding over a VOR) “Attempt to intercept the selected teardrop course outbound.”
Mercedes-Benz Technique
This technique is one of the easiest ways to determine which direction to turn upon entering holding.
STEP ONE - Turn so aircraft is heading directly toward the holding fix.
STEP TWO - Divide the HSI as follows:
STEP THREE - Find out were the outbound holding heading is on your HSI and turn in that direction.
This technique works for right or left holding patterns
Timing
In both cases, Air Force and Civil, you are expected to slow to holding airspeed within 3 minutes of the holding pattern.
Timing in the pattern in based on altitude. On the first pattern, at or below 14,000 ft time outbound for 1 minute; above 14,000 ft time outbound for 1½ minutes.
Start timing when outbound abeam the holding fix or wings level if abeam cannot be determined. Abeam is when the bearing pointer is 90° to the inbound holding course. Inbound, time when wings level inbound. For all additional turns in holding, adjust the out bound time to fly the inbound leg for 1 or 1½ minutes respectively.
Timing adjustments are also required when you have an approach clearance time. You are expected to arrive at the fix on time to start your approach. First calculate the time to fly one pattern. This is the legs plus twice the turn time. A standard rate turn (SRT) is 2 minutes for a 360° turn (or 3° per second). TAS/10 + 7 = SRT. If holding at over 230 KTAS will give an SRT of over 30° of bank. If you hold at over 230 KIAS you need some figures for using 30° of bank. Time for a 360° turn is approximately 1% of TAS. This gives the time for a 360° turn in minutes and tenths of minutes.
Single, Double and Triple Drift (*Triple Drift is the only ICAO approved method)
Drift
Estimating the Crosswind Component:
Drift (in degrees) = Crosswind Component (knots)
NM per minute of TAS
Example: An aircraft flying at 120 knots TAS (2 NM per minute ) has a 20 knot crosswind component (90angle). Drift = 20 2 = 10 degrees.
Obviously, when the reported wind is 90 degrees to the course, then the crosswind component is equal to the wind velocity value. But what do we do when the wind is at some angle between 90 degrees and straight down the course?
You can use the clock method: Imagine a round clock. If a crosswind is 15 degrees off, we equate this to 15 minutes on the clock, which is ¼ of the distance, therefore we take ¼ of the wind value as our crosswind component. Similarly 45 degrees off is ¾ and 60 degrees and greater is 100%. If you want to get precise, 60 deg is .9 and 45 deg is .7.
Timing
In order to do double or triple drift, you need know how long to hold the double or triple. The time required is the time it takes you to make the inbound turn. How do calculate that?
At Standard Rate = 2 minutes for 360 turn, therefore it takes = 1 minute for 180 turn. For Speeds greater than 230 KIAS the bank angle required will be more than 30 deg so use 1% of TAS to compute time to make 360 deg turn at 30 deg bank instead.
Bank Angle for SRT = TAS 10 + 7 for airspeeds less than 230 KIAS
SINGLE DRIFT: In the Air Force, the maximum bank angle in holding is 30°. The minimum bank is 15° or half standard, whichever is less. When using the single drift technique, adjust bank by shallowing turns into the wind and steepening turns downwind one degree for each degree of drift. Since 30° is the maximum bank angle, this only works when your true airspeed is less than 230 knots. Apply single drift on inbound and outbound legs. The maximum drift for this technique depends on speed. Speed determines your standard rate turn. Max drift depends on which number is reached first either ½ standard rate or 15° whichever is less (on one end of the holding pattern) or 30° max bank(on the other end).
THE STEPS FOR SINGLE DRIFT
1. DRIFT = CROSSWIND COMPONENT
NM per minute of TAS
2. TIMING = calculate the time it takes to make the inbound timing
3. PROCEDURES
DOUBLE DRIFT: For double drift, decrease bank angle 1° for each degree of drift when turning into the wind. Use 30° of bank (or SRT which ever is less) turning down wind. After rolling out of the turn,hack the clock! Double the drift correction into the wind on the outbound leg. Hold double drift for the time it takes to make the inbound turn.. Remember at standard rate it takes 1 minute to make a 180° turn; if you’re traveling at faster than standard rate than use 1% of TAS/2. If you haven’t reached your outer DME or timing than go back to single drift. Then use single drift into the wind on the inbound leg. The maximum drift capability is ½ standard rate or 15° whichever is less.
TRIPLE DRIFT: Triple drift is required by ICAO and recommended by the FAA. With this technique, use 30° (or standard rate whichever is less) of bank on both turns. After rolling out of the turn remember to hack the clock! Triple the drift correction into the wind on the outbound leg. Hold the triple drift correction only for the length of time it takes to fly the inbound turn 1 minute at standard rate or approximately 1% TAS/2 if you’re faster than standard rate. After this time, use single drift if you haven’t reached your outer DME or timing. Use single drift into the wind on the inbound leg.
IMPORTANT: Double and triple drift only work if the drift on the outbound leg is applied for the amount of time it takes to complete the inbound turn. Apply double or triple drift correction for the amount of time it takes to fly the inbound turn. At the end of this time either turn inbound or parallel the outbound course applying single drift until the outer distance limit is reached.