When flying an aircraft, there are certain procedures that you must be aware of. One of the most important parts of flying an aircraft is a method of take-off and descent referred to as a “circuit pattern”.
When flying an aircraft, there are certain procedures that you must be aware of. One of the most important parts of flying an aircraft is a method of take-off and descent referred to as a “circuit pattern”.
If you have been in an aeroplane, even in a commercial aircraft, you will probably be familiar with this type of pattern, which includes the aeroplane taxiing for a while on the runway and slowly ascending to a higher altitude or vice versa.
This article will explain what the circuit pattern is and how you can navigate your way in and out of the most common approach type to help you set off for your next flight!
WHAT IS A CIRCUIT?
A circuit pattern is one of the most common flight patterns for approaching and departing from an airport. It consists of five legs and four turns and is usually performed by aircraft flying under VFR or visual approaches and departures.
Usually, most airports require flight patterns that involve turns to the left more than to the right. On the other hand, a good pilot has to keep in mind that every airport may have different kinds of turns suiting its own unique geography.
CIRCUIT LEGS
Circuit legs indicate what part of the flight the aircraft is in. These legs can be termed: Upwind, Crosswind, Downwind, Base and Final. Let's take a common example at hand: A left-handed circuit pattern on a runway 06L with the aircraft facing directly towards the wind or an upwind departure indicates that the pilot is clear for take-off.
To put it simply, the aircraft starts its circuit by performing a normal take-off, enters the take-off/upwind/departure leg while maintaining a climb, and depending on whether performing a go-around or regular departure, it may take two routes.
One of which is the departure route, where the aircraft leaves the circuit pattern directly out of the runway heading or preferably opposite to the circuit pattern. The other option is entering the crosswind leg, for context, this may happen when performing a go-around or maintaining the circuit pattern.
The aircraft must turn 90 degrees away from the runway after reaching a safe altitude and distance from the runway, thus turning perpendicular to the runway. In this case, the aircraft is also perpendicular to the wind, hence the name “crosswind leg”.
To enter the downwind leg, the aircraft clears away from the runway. At a safe distance, the aircraft must turn another 90 degrees downwind parallel to the runway. At this point, the aircraft may receive orders from the tower to go ahead and maintain the approach by turning into the base leg or it may be requested to extend its downwind leg in order to manage traffic. The base leg requires another 90-degree turn towards the runway, which effectively puts the plane in a crosswind situation but in the opposite direction.
At this point the controller input is limited as a touchdown is set. The pilots check for traffic while starting their final turn into the approach leg with another 90-degree turn. At the approach leg and landing, the pilots decide the safety of their landing and depending on all factors, perform a touchdown.
Now let’s take a look at the details of how an aircraft conducts each leg:
Take-off leg
The aircraft takes off and climbs up, maintaining a heading to 500 feet radar altitude or above ground level (AGL). An important consideration here is to account for the wind by crabbing and to always check for traffic. Before this manoeuvre, the aircraft will turn towards the crosswind leg only when there is sufficient clearance from the runway.
Crosswind leg
As the aircraft turns 90 degrees from upwind to crosswind, pilots should be aware of the heading indicator and drift. The aircraft will then maintain a climb to circuit pattern altitude as required by the airport; typically, 1000 ft Above Ground Level (AGL).
Downwind leg
Flying parallel with the desired landing path, the aircraft will maintain an altitude of 1000 ft AGL. The aircraft might gain speed downwind, so pilots must keep an eye on the RPMs, along with adjusting the trim and correcting any drift.
This is also where new aircraft may be joining the circuit which is why it is important to pay close attention to traffic and radio. After passing the middle point of the downwind leg, the pilot performs the pre-landing check.
Examples of pre-landing checks may include: primer lock, master on - magneto both, gauge green (temp/pressure), carburettor on - mixture full rich, power ~1700 RPM etc.
After selecting a touchdown spot on the runway, the aircraft slows down to maximum extended flap speed. As it passes the runway, the pilot starts extending the flaps to 10 degrees to reduce stall speed and improve the angle of descent.
In the case of joining the circuit pattern from the outside, aircraft are most likely to join into the downwind leg of the circuit pattern.
Base leg
Now flying perpendicular to the runway centreline, pilots must listen and scan for traffic that also is on the base leg or final leg. At this point, pilots keep an eye on the speed as they extend 10 more degrees of flaps (20 degrees total). After making the final adjustments, the aircraft begins its descent at 500 feet per minute or as necessary.
Note: The pitch controls the speed, and the power controls the rate of descent and the altitude.
Towards the 90-degree turn into the runway, into the approach leg, pilots look out to ensure the path is clear and traffic is safe. The aircraft remains above 600 ft before turning to the approach leg.
Pilots also take wind into account, so that the aircraft drifts towards the runway, not away from the runway. If the wind comes from the left, the pilot stays on the left by timing the turning, otherwise, if the wind comes from the right, the aircraft stays on the right.
Approach leg and landing
As the aircraft is turned towards the runway, the pilot makes a radio call to report the final descent. The pilot keeps the aircraft approach vector in line with the touchdown location while correcting for drift.
The aircraft slows down to approach speed. While slowing down, the flaps are extended to 30 degrees or as needed. As mentioned above, the pitch controls the speed, and the descent path is controlled by the power. When close to the runway, flaps could be extended to 40 degrees or as much as necessary.
It’s important to note that pilots also have the option to abort or go for a go-around during this point!
FACTORS THAT AFFECT THE CIRCUIT
Traffic
Pilots always keep track of as many aircraft on the same pattern as possible. Try not to cut off a preceding aircraft; this might happen after the transition from the downwind leg to the base leg or from the base leg to the final leg.
The spacing between aircraft is a judgment skill every pilot must develop. Factors that affect spacing include wind direction, wind strength, the performance of the aircraft in operation, and the speed of other aircraft.
Allow preceding aircraft time to land, to taxi off the runway, to backtrack if necessary, or allow aircraft taking off time to speed up or abort in an emergency.
Traffic also comes into play in determining the circuit pattern geometry as airports in close vicinity to each other may have interfering approaches. As such, the downwind leg of the pattern may switch sides depending on other conditions (left-handed circuit to right-handed circuit).
Wind
It is more beneficial for aircraft to land and take-off facing the wind, which in turn dictates what side of the runway is used for landing. This also changes the active side of the runway; that is which side of the circuit pattern is around the airport. In the case of crosswind conditions, there are multiple ways a pilot can account for this.
PHASES OF A FLIGHT
Pre-departure (or planning)
The pre-departure part of the flight is what happens before an aeroplane takes off. This includes the flight crew inspecting the aircraft to ensure that it is safe to fly and a final check of the fuel reserves. In the case where there are other passengers on the flight, doing a headcount and ensuring that everything is in check is also mandatory.
Taxi clearance
Once the aircraft is fully loaded with cargo, passengers, and anything else that may be required for the flight, the aeroplane is given clearance to take off by air traffic control.
Take-off
Before taking off, pilots follow a routine procedure that includes releasing brakes, slowly applying full power, anticipating gyroscopic and slipstream effects, keeping the nose light, checking for full revs, airspeed etc.
Initial climb
Climbing to a higher altitude takes a lot of power, and doing it all at once will put a lot of stress on the engines and can eat up fuel reserves very quickly. This is why pilots “climb” to a higher altitude slowly, gradually increasing the height.
Cruise altitude
This happens after a moment into the flight, after which the aeroplane relatively stops experiencing as much turbulence as during the initial climb. Once the aeroplane has reached the desired altitude, it is referred to as “cruising”.
Descent
This phase is initiated when the destination is within reach. The aeroplane begins its descent, slowly going lower and lower towards the runway. An important consideration here is that if the descent is done with too much speed, it results in a large amount of turbulence and is not the safest way to land a plane.
Landing and Taxi to the terminal
Once the aeroplane has deployed the landing gear and touched down, it begins taxiing on the runway. This continues until the aeroplane has reached the terminal, after which it comes to a complete halt and begins preparing for offloading.
WHERE CAN YOU TRAIN?
There are many dedicated flight academies across the United Kingdom where you can train to become a pilot. Sherburn Aero Club offers in-house training in both the theoretical as well as practical aspects of aviation.
The club prides itself on highly-qualified Certified Flight Instructors (CFI) who are sure to help you gain confidence in your ability to fly an aeroplane and become a better pilot. The training at Sherburn is intensive while offering a relaxed and easy-going environment where the trainees can feel at ease.
If you wish to take the theoretical exams, the club offers services for those who would like to take the tests online. The CAA approves candidates individually for the exam, and once you have the needed approval, you can take the test through the club.
In order to be eligible for the Private Pilot Licence (PPL), the applicant must have a total of 45 hours of flight training, 10 hours out of which must be of solo training. These hours of training are absolutely necessary in order for you to understand how the mechanics of flying an aeroplane operate.
Once you begin training with a CFI, you will gain confidence in your ability to perform circuit patterns and figure out the correct procedures of take-off and landings.
Sherburn is home to a well-maintained fleet of light aircraft which can be hired by members of the club. This saves beginner pilots the hassle of acquiring their own aircraft either on a shared or private basis.
For those who wish to own an aircraft of their own, the club is also home to a marketplace, with the maintenance and engineering facility ensuring that the aircraft you are purchasing is well-maintained and up-to-date.
For those who want to opt for a more rigorous course of training, it may be a good idea to opt for a dedicated flight academy that focuses on getting pilots into the air as soon as possible.
At Sherburn, you have the freedom to set your own pace and it is best suited to individuals who are interested in the social aspect of flying as well.
WHY CHOOSE SHERBURN AERO CLUB
Sherburn Aero Club, which has been operational since 1964, is the ideal place for most of your training and flying needs. It is one of the largest flying clubs in the North of England and also one of the largest in the country.
With a large fleet of new aircraft and an airfield refurbishment with new runways, hangars, and an extended clubhouse, we cater to brand-new flyers who have just started their journey to the skies, as well as seasoned flyers who have been operating aircraft for decades.
If you wish to begin your career in aviation or wish to take to the skies as a hobby, Sherburn’s flight training school offers private and commercial licenses, along with pilot medicals to ensure a smooth journey going forward.
Sherburn offers a dedicated day-long Flight Radiotelephony Operator’s Licence (FRTOL) course for those wishing to get the certification, running the first Sunday of every month.
For those who wish to experience the thrill of a flight for fun or to help fuel their aviation dreams, Sherburn offers experience flights for the newbie, as well as the veteran. The flight experience option is also available for people who wish to take to the skies for special occasions, even if they aren’t into aviation in the long run.
In addition to that, if you are looking for a hangarage for your own aircraft, need servicing or repairs, want to buy a new aircraft or aviation equipment, or are just looking to enjoy and watch the aircraft, Sherburn Aero Club is the place to be.
Call us on 01977 682 674, email us at flightdesk@sherburnaeroclub.com, or message us via our online contact form for more information on circuits and landings.
