A traffic pattern promotes safety by establishing a common track to help pilots determine their landing order and provide common reference. A traffic pattern is also useful to control the flow of traffic, particularly at airports without operating control towers. It affords a measure of safety, separation, protection, and administrative control over arriving, departing, and circling aircraft. Due to specialized operating characteristics, airplanes and helicopters do not mix well in the same traffic environment. At multiple-use airports, regulation states that helicopters should always avoid the flow of fixed-wing traffic.
To do this, be familiar with the patterns typically flown by airplanes. In addition, learn how to fly these patterns in case air traffic control (ATC) requests a fixed-wing traffic pattern be flown.
A normal airplane traffic pattern is rectangular, has five named legs, and a designated altitude, usually 1,000 feet AGL. While flying the traffic pattern, pilots should always keep in mind noise abatement rules and flying friendly to avoid dwellings and livestock. A pattern in which all turns are to the left is called a standard pattern. [Figure 1] The takeoff leg (item 1) normally consists of the aircraft’s flightpath after takeoff. This leg is also called the upwind leg. Turn to the crosswind leg (item 2) after passing the departure end of the runway when at a safe altitude. Fly the downwind leg (item 3) parallel to the runway at the designated traffic pattern altitude and distance from the runway. Begin the base leg (item 4) at a point selected according to other traffic and wind conditions. If the wind is very strong, begin the turn sooner than normal. If the wind is light, delay the turn to base. The final approach (item 5) is the path the aircraft flies immediately prior to touchdown.
|Figure 1. A standard fixed-wing traffic pattern consists of left turns, has five designated legs, and is flown at 1,000' AGL|
Flying a fixed wing traffic pattern at 1,000 feet AGL upon the request of ATC should not be a problem for a helicopter unless conducting specific maneuvers that require specific altitudes. There are variations at different localities and at airports with operating control towers. For example, air traffic control (ATC) may have airplanes in a left turn pattern as airplane pilots are usually seated in the left seat and a right turn pattern for helicopters as those pilots are usually in the right seat. This arrangement affords the best view from each of the cockpits. Always consult the Airport/Facility Directory for the traffic pattern procedures at your airport/heliport.
When approaching an airport with an operating control tower in a helicopter, it is possible to expedite traffic by stating intentions. The communication consists of:
1. The helicopter’s call sign, “Helicopter 8340J.”
2. The helicopter’s position, “10 miles west.”
3. The “request for landing and hover to ...”
To avoid the flow of fixed-wing traffic, the tower often clears direct to an approach point or to a particular runway intersection nearest the destination point. At uncontrolled airports, if at all possible, adhere to standard practices and patterns.
Traffic pattern entry procedures at an airport with an operating control tower are specified by the controller. At uncontrolled airports, traffic pattern altitudes and entry procedures may vary according to established local procedures. Helicopter pilots should be aware of the standard airplane traffic pattern and avoid it. Generally, helicopters make a lower altitude pattern opposite from the fixed wing pattern and make their approaches to some point other than the runway in use by the fixed wing traffic. For information concerning traffic pattern and landing direction, utilize airport advisory service or UNICOM, when available.
The standard departure procedure when using the fixedwing traffic pattern is usually a straight-out, downwind, or right-hand departure. When a control tower is in operation, request the type of departure desired. In most cases, helicopter departures are made into the wind unless obstacles or traffic dictate otherwise. At airports without an operating control tower, comply with the departure procedures stablished for that airport, if any.
An accepted helicopter traffic pattern is flown at 500 feet AGL and consists of right turns. [Figure 2] This keeps the helicopter out of the flow of fixed-wing traffic. A helicopter may take off from a helipad into the wind with a turn to the right after 300 feet AGL or as needed to be in range of forced landing areas. When 500 feet AGL is attained, a right turn to parallel the takeoff path is made for the downwind. Then, as the intended landing point is about 45 degrees behind the abeam position of the helicopter, a right turn is made and a descent is begun from downwind altitude to approximately 300 feet AGL for a base leg.
|Figure 2. A standard helicopter traffic pattern consists of right turns, has 5 designated legs, and is flown at 500' AGL|
As the helicopter nears the final approach path, the turn to final should be made considering winds and obstructions. Depending on obstructions and forced landing areas, the final approach may need to be accomplished from as high as 500 feet AGL. The landing area should always be in sight and the angle of approach should never be too high (indicating that the base leg is too close) to the landing area or too low (indicating that the landing area is too far away).