Patent ID: 7779578

Claim:
A method of providing a retainer for an aircraft hangar door to limit vertical displacement of the hanger door, comprising: a) providing an aircraft hanger having a lower supporting track positioned on one of a lower ground or a floor, an upper guide track and a hanger door, the upper guide track extending across a top and beyond opposite edges of an opening in the hanger, the hanger door having an upper channel member and a roller, the upper channel member having a web portion and a guide extending into the upper guide track and the roller including a grooved support roller that runs along the supporting track; b) positioning a reinforcement apparatus on each of a topside and an underside of the web portion of the channel member, each reinforcement apparatus defining an aperture that extends through the apparatus, and then forming a hole in said upper channel member in axial alignment with the apertures of the reinforcement apparatus, c) inserting a threaded bolt through said apertures and hole, d) securing said bolt to said upper channel member so that said bolt is movable axially toward and away from said upper guide track; and e) axially moving the bolt so that an end of the bolt is positioned a distanced from the upper guide track that is less than a depth of the groove of the roller to limit upper movement of said hanger door and prevent said hanger door from being removed from said lower supporting track.