Parallel Flight Line

A Parallel Flight Line procedure is a straight line flight on a single course that is subsequent and parallel to a Flight Line procedure or another Parallel Flight Line procedure. The aircraft travels from the end of the previous procedure to the site of the current procedure, arriving on a course that is parallel to the previous flight line, and then travels a specific distance on that course to the waypoint at the end of the line. The Parallel Flight Line procedure can be used, along with the Flight Line procedure, to model a search pattern without relying on an area target to define the search area. You can quickly produce several Parallel Flight Line procedures using the Add Parallel Flight Lines tool, which is available from the right-click context menus in the Mission List or when using 3D editing.

Altitude

Altitude parameters define the altitude that the aircraft will attempt to achieve and sustain during the procedure.

Table - Altitude ParametersClosed

Parameter Description
Use Aircraft Default Cruise Altitude Select this check box to define the altitude of the procedure using the default cruise altitude specified in the currently selected cruise performance model.
Altitude If Use Aircraft Default Cruise Altitude is not selected, select an altitude reference (AGL or MSL) and then define the aircraft's altitude for the procedure. The altitude is constrained by the lowest ceiling value of the active performance models in the current mission phase.

Parallel Flight Line Options

Field Description
Procedure Type Select the procedure methodology used to calculate the flight line - Enroute, Basic Point to Point, or Terrain Following.
Orientation Select the placement of the flight line with respect to the previous flight line.
Separation The distance between the flight line and the previous flight line.
Offset / Skew The distance that the aircraft will travel from the end of the previous procedure before it begins to fly the flight line. The course of the offset line will be determined by its distance and the Separation distance, such that the aircraft will begin the flight line at the specified Separation from the previous flight line.
Leg Length The length of the flight line.

Enroute Level Off

Enroute Level Off parameters are used to require the aircraft to attain the altitude specified for the procedure and to define the maneuver used to attain it.

Table - Enroute Level OffClosed

Field Description
Must level off at altitude Select this check box to require the aircraft to level off at the specified altitude. A maneuver is used to bring the aircraft to the altitude specified for a procedure if it is unable to attain that altitude during the course of the procedure. If this option is not selected, the aircraft will simply achieve the highest or lowest - if climbing or descending, respectively - altitude possible while performing the procedure.
Level Off Maneuver

A level off maneuver is used to bring an aircraft to the altitude specified for a procedure, if the aircraft is unable to attain that altitude during the course of that procedure. Select from the following leveling off options:

  • Automatic - STK's Aviator capability will determine if a level off maneuver is required, and the direction of the maneuver if needed.
  • Left Turn - The direction of the maneuver will be a left turn.
  • Right Turn - The direction of the maneuver will be a right turn.
  • No Turn - A maneuver will not be performed. If a level off maneuver is required to reach the specified altitude, then the procedure will be invalidated.

Enroute Options

Enroute Options define the turning performance characteristics of the aircraft during enroute segments of the procedure.

Table - Enroute Options ParametersClosed

Option Description
Use Max Speed When Computing Turn Radii Select this check box to force the aircraft to maintain its cruise speed when turning, even if doing so will result in the aircraft making a turn large enough that it takes longer to complete than it would complete a slower, smaller turn.
Turn Factor The Turn Factor is the maximum amount - expressed as a multiplier - that the turn radius will be increased to minimize the bank angle required to complete the turn. The factor is applied only to turns that are performed enroute to the procedure's first control point. The full circles that correspond (or are tangent) to the start/stop turns at the extended radius may not intersect if the factor is set high enough. This parameter is a limit and may not actually be achieved due to the requirement to generate an appropriate turn sequence. You can adjust the slider or enter the value manually in the box, with the minimum value being 1 and the maximum value being 10.

Enroute Cruise Airspeed

Enroute Cruise Airspeed parameters define the airspeed performance characteristics of the aircraft during enroute segments of the procedure.

Table - Enroute Cruise Airpseed ParametersClosed

Parameter Description
Airspeed Type

Select the method for determining the airspeed from the following options:

  • Minimum Airspeed - constant airspeed at the minimum cruising airspeed for the aircraft.
  • Max Endurance Airspeed - variable airspeed that maximizes the length of time that the aircraft can remain in flight.
  • Max Range Airspeed - variable airspeed that maximizes the distance that the aircraft can fly.
  • Max Performance Airspeed – a custom performance airspeed and fuel flow that you can use to model specific flight conditions.
  • Maximum Airspeed - constant airspeed at the maximum cruising airspeed for the aircraft.
  • Other Airspeed - constant, manually defined airspeed.

With the exception of Other Airspeed, the actual airspeed will be defined by the currently selected cruise performance model, or possibly by the currently selected climb or descent performance model if the aircraft is climbing or descending.
Airspeed Displays the airspeed. If the airspeed type is Other Airspeed, enter the desired airspeed value; otherwise, the calculated value will be displayed and cannot be edited. Select a reference from the drop-down menu - true airspeed (TAS True Airspeed: the speed that the aircraft is moving relative to the airmass that it is flying in.), calibrated airspeed (CAS Calibrated Airspeed: the speed reported by the airspeed indicator, corrected for position and instrument error.), equivalent airspeed (EAS Equivalent Airspeed: the airspeed at sea level (International Standard Atmosphere) at which the dynamic pressure is equal to the dynamic pressure at the aircraft's current true airspeed and altitude.), or Mach The ratio of the aircraft's speed and the speed of sound at the aircraft's altitude, with local atmospheric conditions. number.
Airspeed Profile

Select a method for attaining the procedure's cruise airspeed from the following options:

  • Fly cruise airspeed profile (immediate change) - the aircraft adopts the selected cruise airspeed at the beginning of the procedure
  • Arrive on cruise airspeed (gradual change) - the aircraft begins accelerating or decelerating in the previous procedure so that it arrives at the beginning of the procedure at the selected cruise airspeed.

Enroute Turns

Enroute Turns parameters define the direction that the aircraft will turn during enroute segments of the procedure.

Table - Enroute Turns ParametersClosed

Parameter Description
First Turn

The direction of the turn made from the end of the previous procedure as the aircraft sets its course toward the procedure site. Select from the following options:

  • Automatic - STK's Aviator capability will determine the direction of the turn.
  • Turn Left - Specifies a left turn.
  • Turn Right - Specifies a right turn.
Second Turn

The direction of the turn made to achieve the outbound course at the procedure site. Select from the following options:

  • Automatic - Aviator will determine the direction of the turn.
  • Turn Left - Specifies a left turn.
  • Turn Right - Specifies a right turn.