Holding Procedures 101

by Amir Fleminger

5 min read

It's the final leg of your trip, and everything is set for landing at JFK.

You inform the passengers about the 20 minutes left in flight and ask the flight attendants to prepare the cabin.

Suddenly, the air traffic controller calls:

"Are you ready to copy holding instructions?"

The purpose of holding procedures

Sometimes, there's a need to delay the aircraft in flight. Since parking mid-air isn't an option, we use holding patterns.

Holdings are necessary for various reasons, such as:

Hazardous weather
Traffic congestion
Airport or runway closures
Airport equipment outages
More time for handling abnormal situations or emergencies

A holding pattern is a racetrack-shaped maneuver that keeps the aircraft around a specified fix until ATC and the pilot are ready to resume the flight to the destination or an alternate airport.

The holding pattern shape

A holding pattern consists of four parts:

An inbound leg towards the fix
An outbound leg
Two turns

Bank angle for turns in the hold

The FARs require the smallest bank angle for hold turns, out of the following options:

3º heading change per second (standard-rate turn)
30º bank angle
25º bank angle with a Flight Director system

ATC Holding clearance

ATC can issue either published or non-published holding clearances. Published holding procedures are charted on low/high enroute, arrival, and area charts.

Published hold clearances reduce controller workload and radio chatter. For these, ATC only needs to include:

The holding fix
The direction of the holding pattern relative to the fix (e.g., North, East, South West), and
The Expect Further Clearance (EFC) time.

For non-published holds, the controller must include:

Direction of the holding pattern from the fix (e.g., N, W, S, NE)
Holding fix
Radial, course, airway, or route to hold on
Leg length in miles (if DME or RNAV) or minutes otherwise
Direction of turns (left if specified, otherwise right turns are standard)
Expect Further Clearance (EFC) time

An example of an ATC holding clearance: "Hold West of ETX VOR on the 270º radial Expect Further Clearance at 18:55 Zulu". Since the controller did not mention turn direction, you know that right turns are required.

Once you have the holding clearance, you need to choose the best entry technique based on your position.

Holding pattern entries

Holding Entries

Direct Entry

The direct entry is, as its name suggests, the simplest entry. Use it when approaching the holding fix from the 180º sector in the image.

After crossing the holding fix, turn to the outbound leg in the holding pattern direction to start your first hold.

Parallel Entry

Use this entry when approaching the holding fix from anywhere in the 110º-sized sector in the image.

Cross the fix, fly parallel to the outbound course for one minute, then turn into the hold to intercept the inbound leg.

Note tat you’ll make the first two turns in the "wrong" direction. For example, in a right-hand holding pattern, the turn to the parallel leg and the turn to intercept the inbound are both left-hand turns. Subsequent turns will be right turns in the racetrack pattern.

Teardrop Entry

Upon crossing the fix, turn 30º into the holding side. Follow this heading for 1 minute, then turn in the procedure's direction to intercept the inbound course.

Flying the holding pattern

Reduce speed within three minutes or less of arriving at the fix to cross it at or below the holding speed limit.

Shameless plug:
Choosing a holding pattern entry in the air could be tricky, especially if you receive the clearance at the last moment when close to the fix. For this purpose, I built a little app, Hold Trainer, that makes you better at quickly choosing the best holding entry with practice ATC holding instructions. The app also serves as a holding pattern entry calculator. Check it out here: Hold Trainer for Android and iOS.

Holding speeds restrictions

Altitude (MSL)	Max airspeed (kts)
6000' or below	200 kts
6001-14,000	230 kts
Above 14,000	265 kts
Air Force fields	310 kts *
Navy fields	230 kts *

* Unless published otherwise

Timing

Unless published or instructed otherwise by ATC, the inbound leg time should last:

1 minute at or below 14,000 ft MSL, and
1.5 minutes above 14,000 ft MSL.

Inbound timing:

Begins when the aircraft is wings-level on the inbound leg.
Ends over the holding fix.

Outbound timing:

Begins when the aircraft passes abeam or over the holding fix.
If you can't determine the abeam point, start the timer at the end of the turn outbound.

Time adjustments:

On the first circuit, fly the outbound leg for 1 or 1.5 minutes, depending on your altitude.
Time the inbound leg.
Adjust the next outbound leg as needed to achieve the required inbound timing. If your inbound leg was too short, extend the outbound leg slightly on the next circuit. If the inbound leg was too long, shorten the outbound leg accordingly.

ATC may also specify the leg length as a distance instead of a time.

Wind correction

Determine the wind correction angle: Find the angle required to stay on course during the inbound leg.
Take this wind correction angle and triple it for the outbound leg.

Why triple the correction? We are compensating for the wind drift experienced not only during the outbound leg, but also during the hold turns.

Example: If you need a 5º correction to the right to stay on course inbound, then apply a 15º correction to the right on the outbound leg.

Arriving over the holding fix

A technique commonly used by pilots for remembering the required actions over and abeam the holding fix is the "Five T's" mnemonic:

Turn: the aircraft to follow the desired entry technique.
Time: note the time over the holding fix. Start the timer when wings are level or when abeam the point.
Twist: set the OBS to the inbound course
Throttle: adjust power to maintain holding speed
Talk: advise ATC of the time and altitude at which the aircraft reached the holding fix. E.g.: "<callsign>, over VRB 8,000 ft at 1320 Zulu"
Some add a 6th T to this acronym: "Think (ahead)"

FMS Holds

A Flight Management system (FMS) provides excellent help for performing holds and reducing workload. You plug in the information from the holding clearance: fix, direction, radial, and the system will command the autopilot to fly a perfect hold for you.

With an FMS, you won't have to worry too much about choosing the correct entry or wind correction.

With this in mind, the number one rule of computing applies:

garbage in – garbage out.

Therefore, you must carefully ensure to input the correct information in the FMS and monitor the automation throughout the procedure.

Conclusion

You received the holding instruction with an EFC of 18:55 Zulu, about an hour away. You inquire ATC about the reason for the hold, and they reply its due to traffic congestion on arrival, a common scenario in the New York City area.

Once established in the hold, or when workload permits, it's time to start planning forward.

Ask yourself questions such as:

How long can I stay in the hold with the available fuel?
What is my alternate plan if ATC does not release me by that time?
What is the current weather and availability of other airports in the area if I have to divert?

Knowing the answers to these questions early will help you avoid getting into a low-fuel situation and keep the flight safe.

After holding for about 30 minutes, ATC releases you earlier than expected and clears the flight to proceed to JFK. You continue the arrival and land safely at the airport.