Abstract:
An aircraft aid and method for directing an optimal entry into an aircraft holding pattern are disclosed. The aircraft aid may be affixed over and in registry with a navigational instrument, displayed on and in registry with a navigational instrument, or placed over and in registry with a holding pattern entry diagram. The aircraft aid includes indicia for use in providing a visual for directing an optimal or proper entry into an aircraft holding pattern so that a pilot can have a pictorial view of the proper entry into a holding pattern. It is noted that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to ascertain quickly the subject matter of the technical disclosure and is not be used to interpret or limit the scope or meaning of the claims.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a device, navigational aid and or method that assists pilots in making the transition from ground training to actual flight. More particularly, the present invention relates to a navigational aid, device and/or method for directing a pilot into a holding pattern entry for an aircraft during flight.  
       BACKGROUND OF THE INVENTION  
       [0002]     One of the most difficult tasks for an inexperienced aircraft pilot to understand is the task of properly entering a hold pattern. A hold or fix is a point in the sky where an air traffic controller would like an aircraft to remain until conditions are better for that aircraft to proceed on its flight plan. In order to train pilots for entering a hold pattern, numerous hours are spent on the ground and in the air developing this skill. Previous methods for directing pilots into hold pattern entries have been focused on ground training without providing navigational aids for the pilot to use while in the aircraft. For example, a pilot may mentally rehearse hold pattern entry techniques on the ground while using legacy training devices such as a holding visualizer or a holding pattern computer. These legacy training devices help a pilot simulate holding pattern entry scenarios on the ground but are too cumbersome for a pilot to use in flight and can be confusing when used for ground purposes. Thus, it is difficult for a pilot to make the transition from ground scenarios to actual aircraft holding pattern entries. Specifically, legacy training devices require the pilot to maneuver movable settings on the device to match a simulated scenario in order to receive direction and determine the holding pattern entry that should be used. However, because the legacy training devices can be cumbersome to maneuver and confusing, making the necessary correlations from ground training to actual flight practice is hindered.  
         [0003]     It is with respect to these considerations and others that the present invention has been made.  
       SUMMARY OF THE INVENTION  
       [0004]     Embodiments of the present invention address these problems and others by providing an apparatus and method for directing an optimal entry into an aircraft holding pattern. The apparatus and method enable a user to have a pictorial view of an optimal holding pattern entry during on-the-ground training and or in actual flight.  
         [0005]     One embodiment of the present invention is an apparatus for directing an optimal entry into an aircraft holding pattern. The apparatus includes a transparent disc that has a center and a first side and may be removably affixed over a navigational instrument. The navigational instrument displays a heading of an aircraft and radials from a holding pattern fix of the aircraft. The transparent disc additionally includes indicia to be superimposed over the navigational instrument for use in directing an optimal entry into an aircraft holding pattern. The apparatus also includes a means for removably affixing the transparent disc to the navigational instrument such that the transparent disc is concentric with the navigational instrument. Thus, an aircraft pilot may have a pictorial view of an optimal entry into a holding pattern.  
         [0006]     Another embodiment is a method for directing an optimal entry into an aircraft holding pattern. The method involves receiving an air traffic control instruction for an aircraft to enter a holding pattern and hold on a designated radial off of the holding pattern fix. A transparent disc is placed over in registry with a navigational instrument where the navigational instrument displays a heading of the aircraft and radials off of a holding pattern fix of the aircraft. In registry, for the purposes of this application is intended to mean a condition of correct alignment or proper relative position. The transparent disc also contains indicia for use in directing an optimal entry into an aircraft holding pattern. An optimal entry into a standard or nonstandard holding pattern is then directed based on the position the designated radial on the navigational instrument in relation to the indicia.  
         [0007]     The method may also involve an on the ground training exercise where a holding pattern entry diagram is provided. The holding pattern entry diagram includes a circle with an indicator in the center of the circle representing a simulated holding pattern fix for an imaginary aircraft. The circle is divided into quadrants with the north direction represented at the zero ( 0 ) degree mark of the circle. The holding pattern entry diagram also includes a mark or a line indicating an angle representing the radial on which the imaginary aircraft will hold. The holding pattern entry diagram further includes another mark or line indicating an angle representing the heading of the imaginary aircraft approaching the simulated holding pattern fix. The transparent disc is placed over the holding pattern entry diagram such that a first side or the reverse side of the transparent disc is presented and the center of the transparent disc is concentric with the indicator of the circle. The optimal entry into a standard or a non-standard holding pattern for the imaginary aircraft is then directed based on a position of the mark or line representing the radial on which the imaginary aircraft will hold in relation to the indicia of the transparent disc. The dual capabilities of the transparent disc enable a pilot to easily make a transition from receiving direction and determining holding pattern entries during on-the-ground training to actual flight holding pattern entry determination.  
         [0008]     Still another embodiment of the present invention may be an aircraft aid for directing an optimal entry into an aircraft holding pattern. The aircraft aid may be a device that can be removably affixed to and in registry with a navigational instrument. The device may also be placed over and in registry with a holding pattern entry diagram. The device includes indicia providing a visual for directing an optimal entry into an aircraft holding pattern whereby a pilot can have a pictorial view of the proper entry into a holding pattern.  
         [0009]     Another embodiment of the present invention may be a navigational aid for directing an optimal entry into an aircraft holding pattern. For the purposes of this application a navigational aid includes information or indicia displayed on flight instruments during actual flight. The navigational aid includes indicia displayed via a navigational instrument display. The navigational instrument display identifies a heading of an aircraft and radials including a radial on which the aircraft will hold while in the aircraft holding pattern. The indicia displayed on the navigational instrument display includes an index aligned with the heading of the aircraft identified on the navigational instrument display and at least one section identifying the optimal entry for the aircraft having the heading and entering the holding pattern to hold on the radial identified by the navigational instrument display. The optimal entry is identified based on a position of the radial on which the aircraft will hold relative to the section identifying the optimal entry. Thus, a pilot can have a pictorial view of a proper entry into an aircraft holding pattern.  
         [0010]     Still another embodiment of the present invention is a method for directing an entry into an aircraft holding pattern. The method involves displaying indicia via a navigational instrument display to direct the entry into the aircraft holding pattern. The navigational instrument display identifies a heading of an aircraft and radials on which the aircraft can hold. The method also involves directing the entry into the aircraft holding pattern based on a position of one of the radials, identified on the navigational instrument display and on which the aircraft will hold, in relation to the indicia displayed.  
         [0011]     These and various other features as well as advantages, which characterize the present invention, will be apparent from a reading of the following detailed description and a review of the associated drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1A  is a plan view of a disc illustrating an embodiment of the present invention;  
         [0013]      FIG. 1B  is an exploded perspective of the disc and electrostatic film for affixing the disc to and/or over a navigational instrument;  
         [0014]      FIG. 2  is a plan view of the disc illustrating an embodiment of the present invention;  
         [0015]      FIGS. 3A-3B  illustrate a hypothetical holding pattern entry diagram used for on the ground training without and with placement of the disc of  FIG. 1A  in an embodiment of the present invention;  
         [0016]      FIGS. 4A-4B  are plan views of a navigational instrument without and with placement of the disc of  FIG. 1 A  in an embodiment of the present invention;  
         [0017]      FIGS. 4C-4E  illustrate optimal holding pattern entry diagrams corresponding to use of the transparent disc illustrated in  FIG. 4B  in an embodiment of the present invention;  
         [0018]      FIGS. 5A-5D  are plan views of the navigational instrument of  FIG. 4A  with placement of the transparent disc illustrated in  FIG. 2  and corresponding optimal holding pattern entry diagrams in an embodiment of the present invention;  
         [0019]      FIG. 6  is an illustrative block diagram and screen display generated from a graphics engine and illustrating a display of a navigational instrument for use in directing standard holding pattern entries in an embodiment of the present invention; and  
         [0020]      FIG. 7  is an illustrative block diagram and screen display generated by the graphics engine and illustrating another display of the navigational instrument of  FIG. 6  for use in directing non-standard holding pattern entries in an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0021]     The present invention is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. Embodiments are now described with reference to the figures, in which like numbers indicate like parts throughout the figures.  
         [0022]     Referring now to  FIGS. 1A and 1B , an apparatus for directing an optimal entry into an aircraft holding pattern in an embodiment of the present invention will be described. An embodiment of the present invention as illustrated in  FIGS. 1A-1B  comprises a disc  100  having indicia that may be superimposed over a navigational instrument or a holding pattern entry diagram. In alternative embodiments, the disc  100  may be transparent. Additional details regarding the navigational instrument and holding pattern entry diagrams will be described below with respect to  FIGS. 3A-5D .  
         [0023]     Referring again to  FIG. 1A , the indicia identifies an index  107  of the transparent disc  100  to be aligned with the heading of an aircraft displayed on the navigational instrument or the heading of a holding pattern entry diagram for ground training or simulation. The indicia also radially divide the transparent disc into three sections  102 ,  104 , and  106 . Each section represents an area within which an optimal entry may be identified. Section  102  defines a teardrop entry and is represented by an area that spans 70 degrees in a clockwise direction from the index  107  about the center  109  of the disc  100 . A parallel entry section  104  is represented by an area that spans 110 degrees in a counter-clockwise direction from the index  107  about the center  109  of the transparent disc  100 . Lastly, a direct entry section  106  is represented by an area that spans 180 degrees about the center  109  of the transparent disc  100 . The indicia may also distinguish each of the sections by a color, a letter, as is the case for the present embodiment, and or a name of the optimal entry identified within each of the sections. Additional details regarding teardrop, parallel, and direct entries will be described below with respect to  FIGS. 4C-5D .  
         [0024]     The indicia, via a label  108 , further identifies whether the optimal entry identified is for a standard right hand holding pattern or a non-standard left hand holding pattern. The label  108  is for standard right hand holding patterns as indicated by the ‘STANDARD RH’printed on the label affixed to a first side of the disc  100 .  
         [0025]      FIG. 1B  is an exploded perspective view of the disc  100  and electrostatic film  130  for affixing the disc  100  to and/or over a navigational instrument in an embodiment of the present invention. The apparatus  101  includes the disc  100  and an electrostatic film  130  to be removably adhered to the disc  100  to enable the disc to be removably affixed or adhered to a navigational instrument. The disc may be made of a variety of materials including bendable plastic that is transparent. The electrostatic film  130 / 130 ′ may also be transparent. In the alternative, the disc  100  may also be made of electrostatic film. It will be appreciated by those skilled in the art that other forms of affixing the disc  100  to the navigational instrument may also be used such as adhesive or sizing the disc diameter such that the disc  100  press fits within a recessed area over the face of the navigational instrument.  
         [0026]      FIG. 2  is a plan view of the hold director for nonstandard holding pattern entries in an embodiment of the present invention. The disc  200  may be a separate disc or, in the alternative, be a reverse or opposite side of the disc  100 . As similarly described above with respect to  FIG. 1A , the indicia of the disc  200  identifies an index  207  of the disc  200  to be aligned with the heading of an aircraft displayed on a navigational instrument or the heading of a holding pattern entry diagram for ground training or simulation. The indicia also radially divide the disc  200  into three sections  202 ,  204 , and  206 . Each section represents an area within which an optimal entry may be identified. The teardrop entry section  202  is represented by an area that spans  70  degrees in a counterclockwise direction from the index  207  about the center  209  of the disc  200 . The parallel entry section  204  is represented by an area that spans 110 degrees in a clockwise direction from the index  207  about the center  209  of the disc  200 . Lastly, the direct entry section  206  is represented by an area that spans 180 degrees about the center  209  of the disc  200 . The indicia may also distinguish each of the sections by a color, a letter, as is the case for the present embodiment, and or a name of the optimal entry identified within each of the sections. It should be appreciated that in the case where the disc  200  is the reverse side of the disc  100  that is transparent, the two sides of the disc may share indicia with the exception of the label  108 .  
         [0027]     The indicia, via a label  208 , further identifies whether the optimal entry identified is for a standard right hand holding pattern or a non-standard left hand holding pattern. The label  208  is for nonstandard left hand holding patterns as indicated by the ‘NON-STANDARD LH’ printed on the label affixed to the transparent disc  200 .  
         [0028]      FIGS. 3A-3B  illustrate a hypothetical holding pattern entry diagram without and with placement of the disc  100  of  FIG. 1A  used for on the ground training in an embodiment of the present invention. For the purposes of describing  FIGS. 3A-3B , the disc  100 ′ is transparent. A holding pattern entry diagram  300  is drawn for use in an on the ground training exercise for directing an optimal entry into a holding pattern. A circle  301  is drawn with an indicator  305  in the center of the circle representing a simulated holding pattern fix for an imaginary aircraft. The circle is then divided into quadrants with a north direction represented at a 0 degree mark of the circle  301 , an east direction represented at a 90 degree mark, a south direction represented at a 180 degree mark, and a west direction represented at a 270 degree mark.  
         [0029]     A radial on which the imaginary aircraft is to hold and a heading at which the imaginary aircraft approaches the simulated holding pattern fix are then selected. A line  304  is drawn from the indicator  305  that intersects the circle  301  at an angle representing the radial. As illustrated in  FIG. 3A , the radial selected is the 160 degree radial, southeast standard holding pattern. A heading line  302  is drawn from the indicator  305  that intersects the circle  301  at an angle representing the heading selected. In  FIG. 3A , the heading of 220 degrees southwest has been selected. The transparent disc  100 ′ is placed over the circle  301  such that the center  109  of the transparent disc  100 ′ is concentric with the indicator  305  and the index  107 ′ is substantially aligned with the heading line  302  of the holding pattern entry diagram  300 .  
         [0030]     Next an optimal entry into a standard holding pattern is directed for the imaginary aircraft based on the position of the line  304 , representing the radial selected, in relation to the indicia of the transparent disc  100 ′. Because the line  304  is positioned within the parallel entry section  104 ′, the optimal and recommended entry into a standard holding pattern holding on the southeast 160 radial for an aircraft heading  220  degrees southwest is the parallel entry described below. Thus, a pilot can easily make a transition from determining holding pattern entries during on the ground training to receiving holding pattern entry direction from the transparent disc  100 ′ during actual flight. Additional details regarding receiving holding pattern entry direction during flight will be described below with respect to  FIGS. 4A-5D .  
         [0031]      FIGS. 4A-4B  are plan views of a navigational instrument  400  without and with placement of the transparent disc  100 ′ of  FIG. 3B  in an embodiment of the present invention.  FIG. 4A  illustrates a navigational instrument  400 . The navigational instrument displays a heading  402  of an aircraft while the aircraft is in flight, in this case the heading is 220 degrees southwest. Thus, the navigational instrument accordingly rotates as the heading of an aircraft changes. The navigational instrument  400  also displays radials from a holding pattern fix of the aircraft where the zero (0) degree radial  406  represents true north. The transparent disc  100 ′ includes indicia to be superimposed over the navigational instrument  400  for use in directing an optimal entry into an aircraft holding pattern as illustrated in  FIG. 4B .  
         [0032]     Referring also to  FIG. 4B , a means for affixing the transparent disc  100 ′, such as the electrostatic film  130  described above with respect to  FIG. 1A , is utilized to removably affix the transparent disc  100 ′ over or to the navigational instrument  400  such that the transparent disc  100 ′ is concentric with a center  407  of the navigational instrument. Also, the index  107 ′ is substantially aligned with the heading  402  of the aircraft, which in  FIG. 4B  is 220 degrees southwest. It should be appreciated that the transparent disc  100 ′ may be the same, smaller, or larger in diameter as compared to the face of the navigational instrument  400 . When the disc is not transparent, the diameter may be smaller than the face of the navigational instrument such that the radials of the navigational instrument  400  appear just above the circumference of the disc.  
         [0033]     The indicia of the transparent disc  100 ′ also distinguishes each of the sections  104 ′,  108 ′, and  110 ′ as representing an area within which an optimal entry into aircraft holding patterns is identified. The sections  104 ′,  108 ′, and  110 ′ respectively identify optimal entries into aircraft holding patterns holding on a radial displayed on the navigational instrument  400  and over which at least one of the sections  104 ′,  108 ′, and  110 ′ is superimposed. As a result, the aircraft pilot will have a pictorial view of an optimal entry into a holding pattern. Additional details regarding optimal holding pattern entries represented by the sections  104 ′,  108 ′, and  110 ′ are described below with respect to  FIGS. 4C-4E .  
         [0034]      FIG. 4C  is a holding pattern entry diagram illustrating a holding pattern  432  and an entry  430  for an actual flight. In response to receiving an air traffic control instruction to hold southeast on the 160 radial  404 , the pilot flying the aircraft  435  may view the navigational instrument  400  through the transparent disc  100 ′ and see the optimal entry for the holding pattern. As seen in  FIG. 4B , the 160 radial  404  is displayed within the parallel entry section  104 ′ for the aircraft  435  approaching a holding pattern fix  433  at a heading  402  of 220 degrees southwest.  
         [0035]     For aircraft approaching a fix  433  at a heading  402  of 220 degrees southwest to hold on the 160 radial  404 , a parallel entry  432  would require a minimum number of turns to enter the holding pattern  432  and is thus, the optimal entry directed by the transparent disc  100 ′. A pilot may begin a parallel entry  430  after the aircraft  435  crosses the fix  433  which marks the start of the outbound leg time, which is usually one minute. After crossing the fix  433 , the pilot should turn to the heading of the radial  404  that the hold is predicated on, in this case  160  southeast. After one minute and flying parallel to the radial  404 , the aircraft  435  should be turned back on the protected side of the aircraft to the fix  433 . For a standard holding pattern, a turn to the protected side in a parallel entry would be a left turn  
         [0036]      FIG. 4D  is a holding pattern entry diagram illustrating a holding pattern  440  and an entry  441  for an actual flight. In response to receiving an air traffic control instruction to hold east on the 90 radial  408 , the pilot flying the aircraft  435  may view the navigational instrument  400  through the transparent disc  100 ′ and see the optimal entry for the holding pattern. As seen in  FIG. 4B , the 90 radial  408  is displayed within the direct entry section  108 ′ for the aircraft  435  approaching a holding pattern fix  433  at a heading  402  of 220 degrees southwest.  
         [0037]     For aircraft approaching a fix  433  at a heading  402  of 220 degrees southwest to hold on the 90 radial  408 , a direct entry  441  would require a minimum number of turns to enter the holding pattern  432  and is thus, the optimal entry directed by the transparent disc  100 ′. A pilot may begin a direct entry  441  after the aircraft  435  crosses the fix  433 . After crossing the fix  433 , the pilot should turn to the heading of the radial  408  that the hold is predicated on, in this case 90 east. For a standard holding pattern the turn should be a right turn. When the aircraft  435  becomes abeam the fix, the time for an outbound leg is begun, usually one minute. The aircraft  435  proceeds for one minute and then a right turn is made to intercept the 90 east radial  408  on which the hold is predicated.  
         [0038]      FIG. 4E  is a holding pattern entry diagram illustrating a holding pattern  452  and an entry  450  for an actual flight. In response to receiving an air traffic control instruction to hold west on the 270 radial  410 , the pilot flying the aircraft  435  may view the navigational instrument  400  through the transparent disc  100 ′ and see the optimal entry for the holding pattern. As seen in  FIG. 4B , the 270 radial  410  is displayed within the teardrop entry section  110 ′ for the aircraft  435  approaching a holding pattern fix  433  at a heading  402  of 220 degrees southwest.  
         [0039]     For aircraft approaching a fix  433  at a heading  402  of 220 degrees southwest to hold on the 270 radial  410 , a teardrop entry  450  would require a minimum number of turns to enter the holding pattern  452  and is thus, the optimal entry directed by the transparent disc  100 ′. A pilot may begin a teardrop entry  450  after the aircraft  435  crosses the fix  433 . After crossing the fix  433  for standard holding patterns, the pilot should turn to the heading of the radial  410  that the hold is predicated on minus  30  degrees, in this case 270 west−30=240 southwest. The aircraft  435  then proceeds outbound for one minute and makes a turn to intercept the 270 radial  410  on which the hold is predicated. For a standard holding pattern the turn should be a right turn.  
         [0040]      FIG. 5A  is a plan view of the navigational instrument  400  with placement of the transparent disc  200 ′ illustrated in  FIG. 2  in an embodiment of the present invention. The navigational instrument  400  displays a heading  402  of an aircraft while the aircraft is in flight, in this case the heading is 220 degrees southwest. The navigational instrument  400  also displays radials from a holding pattern fix of the aircraft where the zero (0) degree radial  406  represents true north. The transparent disc  200 ′ contains indicia to be superimposed over the navigational instrument  400  for use in directing an optimal entry into a non-standard aircraft holding pattern as illustrated in  FIG. 5A .  
         [0041]     Still referring to  FIG. 5A  for nonstandard holding patterns, a means for affixing the transparent disc  200 ′, such as the electrostatic film  130  described above with respect to  FIG. 1A , is utilized to removably affix the transparent disc  200 ′ over the navigational instrument  400  such that the transparent disc  200 ′ is concentric with a center  407 , shown in  FIG. 4A , of the navigational instrument. Also, the index  207 ′ is substantially aligned with the heading  402  of the aircraft, for example 220 degrees southwest. It should be appreciated that the transparent disc  200 ′ may be the same, smaller, or larger in diameter as the face of the navigational instrument  400 . It should also be appreciated that the transparent disc  200 ′ may be the opposite side of the transparent disc  100 ′. If the disc is not transparent as, the diameter may be smaller than the face of the navigational instrument such that the radials of the navigational instrument  400  appear just above the circumference of the disc.  
         [0042]     The indicia of the transparent disc  200 ′ also distinguishes each of the sections  202 ′,  204 ′, and  206 ′ as representing an area within which an optimal entry into nonstandard aircraft holding patterns is identified. The sections  202 ′,  204 ′, and  206 ′ respectively identify optimal entries into aircraft holding patterns holding on a radial displayed on the navigational instrument  400  and over which at least one of the sections  202 ′,  204 ′, and  206 ′ is superimposed. As a result, the aircraft pilot will have a pictorial view of an optimal entry into a holding pattern. Additional details regarding optimal holding pattern entries represented by the sections  202 ′,  204 ′, and  206 ′ are described below with respect to  FIGS. 5B-5D .  
         [0043]      FIG. 5B  is a holding pattern entry diagram illustrating a holding pattern  518  and an entry  520  for an actual flight. In response to receiving an air traffic control instruction to hold southeast on the 160 radial  404  nonstandard or left turns, the pilot flying the aircraft  435  may view the navigational instrument  400  through the transparent disc  200 ′ and see the optimal entry for the holding pattern. As seen in  FIG. 5A , the 160 radial  404  is displayed within the teardrop entry section  202 ′ for the aircraft  435  approaching a nonstandard holding pattern fix  433  at a heading  402  of 220 degrees southwest.  
         [0044]     For aircraft approaching a fix  433  at a heading  402  of 220 degrees southwest to execute a nonstandard hold on the 160 radial  404 , a teardrop entry  520  would require a minimum number of turns to enter the holding pattern  518  and is thus, the optimal entry directed by the transparent disc  200 ′. A pilot may begin a teardrop entry  520  after the aircraft  435  crosses the fix  433 . After crossing the fix  433  for nonstandard holding patterns, the pilot should turn to the heading of the radial  404  that the hold is predicated on plus 30 degrees, in this case 160 southeast+30=190 southwest. The aircraft  435  then proceeds outbound for one minute and makes a turn to intercept the 160 radial  404  on which the hold is predicated. For a nonstandard holding pattern the turn should be a left turn.  
         [0045]      FIG. 5C  is a holding pattern entry diagram illustrating a holding pattern  530  and an entry  528  for an actual flight. In response to receiving an air traffic control instruction to execute a nonstandard hold east on the 90 radial  408 , the pilot flying the aircraft  435  may view the navigational instrument  400  through the transparent disc  200 ′ and see the optimal entry for the holding pattern. As seen in  FIG. 5A , the 90 radial  408  is displayed within the direct entry section  206 ′ for the aircraft  435  approaching a nonstandard holding pattern fix  433  at a heading  402  of 220 degrees southwest.  
         [0046]     For aircraft approaching a fix  433  at a heading  402  of 220 degrees southwest to execute a nonstandard hold on the 90 radial  408 , a direct entry  528  would require a minimum number of turns to enter the holding pattern  530  and is thus, the optimal entry directed by the transparent disc  200 ′. A pilot may begin a direct entry  528  after the aircraft  435  crosses the fix  433 . After crossing the fix  433 , the pilot should turn to the heading of the radial  408  that the hold is predicated on, in this case 90 east. For a nonstandard holding pattern the turn should be a left turn. When the aircraft  435  becomes abeam the fix, the time for an outbound leg is begun, usually one minute. The aircraft  435  proceeds for one minute and then a left turn is made to intercept the 90 east radial  408  on which the hold is predicated.  
         [0047]      FIG. 5D  is a holding pattern entry diagram illustrating a holding pattern  542  and an entry  540  for an actual flight. In response to receiving an air traffic control instruction to execute a nonstandard hold west on the 270 radial  410 , the pilot flying the aircraft  435  may view the navigational instrument  400  through the transparent disc  200 ′ and see the optimal entry for the holding pattern. As seen in  FIG. 5D , the 270 radial  410  is displayed within the parallel entry section  204 ′ for the aircraft  435  approaching a holding pattern fix  433  at a heading  402  of 220 degrees southwest.  
         [0048]     For aircraft approaching a fix  433  at a heading  402  of 220 degrees southwest to execute a nonstandard hold on the 270 radial  410 , a parallel entry  540  would require a minimum number of turns to enter the holding pattern  542  and is thus, the optimal entry directed by the transparent disc  200 ′. A pilot may begin a parallel entry  540  after the aircraft  435  crosses the fix  433  and marks the start of the outbound leg time, which is usually one minute. After crossing the fix  433 , the pilot should turn to the heading of the radial  410  that the hold is predicated on, in this case 270 west. After one minute of flying parallel to the radial  410 , the aircraft  435  should be turned back on the protected side of the aircraft to the fix  433 . For a nonstandard holding pattern, a turn to the protected side in a parallel entry would be a right turn.  
         [0049]     The transparent disc  200 ′ is preferably formed of a bendable material such as plastic. Examples of plastics that may be used to form the transparent discs include, but are not limited to polypropylene and electrostatic film.  
         [0050]      FIG. 6  is an illustrative block diagram and screen display generated from a graphics engine  605  illustrating a display  603  of a navigational instrument  600  for use in directing standard holding pattern entries in an embodiment of the present invention. One skilled in the art will recognize that the graphics display  603  may be a liquid crystal display (LCD) utilizing digital signals. The graphics display  603  may also include a cathode ray tube (CRT) utilizing a graphics display system, such as a video graphics array (VGA) utilizing analog signals. In addition to displaying a heading  602  of the aircraft and other radials, the display  603  displays indicia that identify an index  607  aligned with the heading  602  of the aircraft. The indicia also radially divide the graphic display  603  into three sections  601 ,  604 , and  606 .  
         [0051]     Each section represents an area within which an optimal entry into a holding pattern is identified for holding radials displayed within the respective section as the index aligns with the heading  602 . Section  601  defines a teardrop entry and is represented by an area that spans 70 degrees in a clockwise direction from the index  607  about the center  609  of the display  603 . A parallel entry section  604  is represented by an area that spans 110 degrees in a counterclockwise direction from the index  607  about the center  609  of the display  603 . Lastly, a direct entry section  606  is represented by an area that spans 180 degrees about the center  609  of the display  603 . The indicia may also distinguish each of the sections by a letter, as is the case for the present embodiment, a color, and or a name of the optimal entry identified within each of the sections.  
         [0052]     The sensor  608  provides navigational inputs to the graphics engine  605 . Thus, as the heading  602  of the aircraft changes, the sensor  608  detects the change and provides corresponding inputs to the graphics engine  605 . The graphics engine  605  then updates the display  603  to display the new heading  602  and updates the index  607  to align with the new heading  602 . The indicia, via an indicator  611 , may further identify whether the optimal entry identified is for a standard right hand holding pattern or a non-standard left hand holding pattern. The indicator  611  is for standard right hand holding patterns as indicated by the ‘STD RH’ displayed on the graphic display  603 .  
         [0053]      FIG. 7  is an illustrative block diagram and screen display generated by the graphics engine  605  and illustrating the display  603  of the navigational instrument  600  of  FIG. 6  for use in directing non-standard holding pattern entries in an embodiment of the present invention. In addition to displaying a heading  602  of the aircraft and other radials, the display  603  displays indicia that identify the index  607  aligned with the heading  602  of the aircraft. The indicia also radially divide the graphic display  603  into three sections  701 ,  704 , and  706 .  
         [0054]     Each section represents an area within which an optimal entry into a holding pattern is identified for holding radials displayed within the respective section as the index  607  aligns with the heading  602 . Section  701  defines a teardrop entry and is represented by an area that spans 70 degrees in a counterclockwise direction from the index  607  about the center  609  of the display  603 . A parallel entry section  704  is represented by an area that spans 110 degrees in a clockwise direction from the index  607  about the center  609  of the display  603 . Lastly, a direct entry section  706  is represented by an area that spans 180 degrees about the center  609  of the display  603 . The indicia may also distinguish each of the sections by a letter, as is the case for the present embodiment, a color, and or a name of the optimal entry identified within each of the sections.  
         [0055]     The sensor  608  provides navigational inputs to the graphics engine  605 . Thus, as the heading  602  of the aircraft changes, the sensor  608  detects the change and provides corresponding inputs to the graphics engine  605 . The graphics engine  605  then updates the display  603  to display the new heading  602  and updates the index  607  to align with the new heading  602 . The indicia, via an indicator  711 , may further identify whether the optimal entry identified is for a standard right hand holding pattern or a non-standard left hand holding pattern. The indicator  711  is for nonstandard left hand holding patterns as indicated by the ‘NSTD LH’ displayed on the graphic display  603 .  
         [0056]     Thus, the present invention is presently embodied as a method and apparatus for directing an entry into an aircraft holding pattern.  
         [0057]     Although the present invention has been described with reference to specific details of certain embodiments thereof, it is not intended that such details should be regarded as limitations upon the scope of the invention except as and to the extent that they are included in the accompanying claims.  
         [0058]     The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.