Method and apparatus for aiming aircraft visual approach slope indicator

A method for adjusting the vertical angle of an aircraft visual approach slope indicator, wherein the approach indicator includes a vertically adjustable housing containing at least one landing light mounted behind a horizontal crossbar across one housing wall to direct light through a horizontal aiming slit in the opposited housing wall at an adjustable vertical angle towards approaching aircraft, the crossbar being centrally aligned between said light and the slit and the angle of the directed light being determined by adjustment of the vertical angle of the slope indicator housing, comprising the steps of:

• mounting a T-shaped calibration bar of a calibration assembly on a support;
• leveling said calibration bar by adjusting support pin resting on said support;
• said T-shaped calibration bar comprising:
• a leg and crossarm, a support pin mounted at each end of the crossarm, and a third pin mounted on the remote end of the T-leg, said T-leg pin and at least one of said crossarm pins being adjustable for leveling the calibration bar;
• said calibration assembly further comprising:
• means for indicating when the calibration bar is level;
• and means for removably mounting an alignment assembly on top of and parallel to the calibration bar T-leg;
• mounting an alignment assembly on top of and parallel to the calibration bar at the same points and in the same manner as said alignment assembly is designed to be mounted on said slop indicator, said alignment assembly further comprising:
• a first rigid linear member for projecting into said housing through said slit and having means for removably securing its inner end adjacent the vertical center of said landing light;
• a second rigid linear member pivotally mounted on said first member in a vertical plane parallel to the vertical plane of said first member;
• means for indicating when the second member is horizontal;
• and means for indicating the vertical pivot angle between said first and second members when said second member is horizontal to thereby show the slope of said approach indicator;
• rotating the second bar member to a position parallel to the first member;
• adjusting the alignment assembly until a horizontal position is shown by said indicating means;
• removing the alignment assembly from the calibration bar;
• mounting the alignment assembly on the aircraft visual approach slope indicator by inserting said remote end of the first member through the indicator housing slit and securing said first member to said crossbar whereby said first member assumes the vertical angle of the directed light;
• rotating the second member to form the desired angle of the directed light between the first and second members;
• adjusting the vertical angle of the indicator housing until the second member is indicated to be in a horizontal position;
• and
• removing the alignment assembly from the indicator housing.

A system for determining alignment of an aircraft visual approach slope indicator by use of a properly calibrated alignment assembly,

• wherein the approach indicator housing contains at least one landing light spaced from an aiming slit,
• and wherein the alignment assembly includes a first rigid linear member for projecting into said housing through said slit and having means for removably securing its inner end adjacent the vertical center of said landing light, a second rigid linear member pivotally mounted on said first member in a vertical plane parallel to the vertical plane of said first member, means for indicating when the second member is horizontal, and means for indicating the vertical pivot angle between said first and second members when said second member is horizontal to thereby show the slope of said approach indicator, the combination with said alignment assembly of calibration means comprising:
• a calibration bar comprising a leg and crossarm, a support mounted at each end of the crossarm, and a third support mounted on the remote end of said leg, said leg support and at least one of said crossarm supports being adjustable for leveling the calibration bar;
• means for indicating when the calibration bar is level;
• and,
• means for removably mounting said first linear member of the alignment assembly on top of and parallel to the calibration bar.

A system for determining the vertical angle of an aircraft visual approach slope indicator by use of a properly calibrated alignment assembly,

• wherein the approach indicator includes a vertically adjustable housing containing at least one landing light mounted behind a crossbar on one housing wall to direct light at an adjustable vertical angle towards approaching aircraft through an aiming slit in the opposite housing wall, the crossbar being centrally aligned between said light and the slit and the adjustable angle being determined by adjustment of the vertical angle of the slope indicator housing,
• and wherein the alignment assembly includes a first rigid linear bar for projecting into said housing through said slit and having means for detachably securing its inner end to said crossbar, whereby said first bar assumes the vertical angle of the directed light, a second rigid linear bar for location outside the housing pivotally mounted on the outer end of said first bar in a vertical plane parallel to the vertical plane of said first bar, said second bar being directable rearwardly back towards the housing and having clamping means mounted on its rearward end, a slotted angle plate secured to the first bar adjacent the rearward end of the second bar for engagement by said clamping means passing through the slot of said plate, said angle plate being marked so that the upper horizontal surface of the second bar is aligned with an indication of the angle formed between the first and second bars when the second bar is horizontal, and means for indicating when the second bar is horizontal, said horizontal indicating means, said first and second bars, and said angle plate constituting an alignment assembly, the combination with said alignment assembly of calibration means comprising:
• a support member adapted to mount a calibration bar;
• a T-shaped calibration bar comprising a T-leg and crossarm, a pin mounted at each end of the crossarm, and a third pin mounted on the remote end of the T-leg, said pins being adapted to be positioned on said support member and said T-let pin and at least one of said crossarm pins being adjustable for leveling the calibration bar;
• means for indicating when the calibration bar is level;
• and
• means for removably mounting said first linear bar of the alignment assembly on top of and parallel to the calibration bar T-leg at the same points on said first linear bar and in substantially the same manner as said first linear bar is designed to be mounted on said slope indicator.

An apparatus for determining the vertical angle of an aircraft visual approach slope indicator, wherein the approach indicator includes a vertically adjustable housing containing at least one landing light mounted behind a crossbar on one housing wall to direct light at an adjustable vertical angle towards approaching aircraft through an aiming slit in the opposite housing wall, the crossbar being centrally aligned between said light and the slit and the adjustable angle being determined by adjustment of the vertical angle of the slope indicator housing, comprising:

• a first rigid linear bar for projecting into said housing through said slit and having means for automatically detachably securing the inner end of said first bar to said crossbar when the first bar contacts the crossbar, whereby said first bar assumes an operative position aligned with the vertical angle of the directed light;
• a second rigid linear bar for location outside of the housing when the first bar is operatively positioned, said second bar being pivotally mounted on the outer end of of said first bar in a vertical plane parallel to the vertical plane of said first bar, said second bar being directable rearwardly back towards the housing and having clamping means mounted on its rearward end;
• a slotted angle plate secured to the first bar adjacent the rearward end of the second bar for engagement by said clamping means passing through the slot of said plate, said angle plate being marked so that the upper horizontal surface of the second bar is aligned with an indication of the angle formed between the first and second bars when the second bar is horizontal;
• and,
• means mounted on said second bar for indicating when the second bar is horizontal, said horizontal indicating means, said first and second bars, and said angle plate constituting an alignment assembly.