Method for attaching a split winglet to a wing

A method of securing a split winglet to a wing tip of a wing of an aircraft comprising the steps of:

• attaching an upper winglet to an upper winglet attachment portion of a winglet attach fitting having a wing attachment portion by:
• insertably stove-piping or sliding a generally hollow, box-shaped terminal end of the upper winglet attachment portion into a generally hollow interior of the upper winglet at an upper winglet root end, the upper winglet attachment portion oriented at a dihedral angle;
• and
• extending at least one fastener through the upper winglet attachment portion and into an upper winglet skin;
• attaching a lower winglet to a lower winglet attachment portion of the winglet attach fitting by:
• insertably stove-piping or sliding a generally hollow, box-shaped terminal end of the lower winglet attachment portion into a generally hollow interior of the lower winglet at a lower winglet root end, the lower winglet attachment portion oriented at an anhedral angle;
• and
• extending at least one fastener through the lower winglet attachment portion and into a lower winglet skin;
• removably attaching the wing attachment portion to the wing tip using fasteners to secure the split winglet to the wing, the upper winglet extending upwardly from the wing at the dihedral angle, the lower winglet separate from the upper winglet and extending downwardly from the wing at the anhedral angle;
• wherein the lower winglet and the upper winglet are non-articulating when the wing attachment portion is attached to the wing tip;
• wherein the upper winglet attachment portion and the lower winglet attachment portion intersect one another at the wing attachment portion;
• and
• wherein the upper winglet attachment portion and the lower winglet attachment portion each extend from an outboard side of the wing attachment portion, and in opposing relation to an inboard side of the wing attachment portion.