Rivetless nutplates for aircraft

A method of maintaining structural integrity of an airframe while attaching a window to the airframe during manufacture of an aircraft, the method comprising the steps:

• applying to a bonding surface of a nutplate an adhesive;
• maintaining the adhesive-coated bonding surface of the nutplate adjacent an interior surface of the airframe;
• and
• allowing the adhesive to cure;
• wherein the adhesive is selected such that the nutplate is secured by the adhesive such that:
• the bond between the nutplate and the airframe will withstand a bolt-fastening torque of at least 60 inch pounds;
• the bond between the nutplate and the airframe will withstand cycling over a temperature range from approximately −55 degrees Celsius to approximately 82 degrees Celsius;
• wherein the adhesive comprises at least one of composition 1 in Table 1 and composition 2 in Table 2:
• TABLE 1
• composition 1
• approximate %
• Ingredient
• by Wt
• Methyl Methacrylate
• 40-70
• Chlorosulfonated Polyethylene
• 10-30
• Acrylic Polymer
• 5-10
• Acrylic Polymer
• 3-7
• Maleic Acid
• 1-5
• Cumene Hydroperoxide
• 0.5-1.5
• 2,6-di-tert-Butyl-p-Cresol
• 0.5-1.5
• and
• TABLE 2
• composition 2
• approximate %
• Ingredient
• by Wt
• METHYLENE PHENYLENE ISOCYANATE
• 35
• URETHANE PREPOLYMER
• 19-23
• MDI HOMOPOLYMER
• 12-16
• CALCIUM SODIUM ALUMINOSILICATE
• 8-12
• TALC
• 8-12
• URETHANE PREPOLYMER
• 3-7
• AMORPHOUS SILICA
• 2-6.

A method for attaching a window to an airframe via a rivetless nutplate, comprising:

• applying to a bonding surface of the nutplate an adhesive;
• inserting through a hole in the airframe an elastomeric fixture attached to a nut of the nutplate, and pulling the elastomeric fixture to apply tension to the elastomeric fixture to hold the adhesive-coated bonding surface of the nutplate adjacent an interior surface of the airframe;
• allowing the adhesive to cure;
• removing the elastomeric fixture from the nut of the nutplate;
• and
• installing a bolt through a hole of a retainer, through the hole in the airframe, and into the nutplate;
• the retainer being in contact with and securing the window to the airframe;
• wherein the adhesive comprises at least one of composition 1 in Table 1 and composition 2 in Table 2:
• TABLE 1
• composition 1
• approximate %
• Ingredient
• by Wt
• Methyl Methacrylate
• 40-70
• Chlorosulfonated Polyethylene
• 10-30
• Acrylic Polymer - N.J.T.S. Reg No. 800941-5008P
• 5-10
• Acrylic Polymer - N.J.T.S. Reg No. 800941-5007P
• 3-7
• Maleic Acid
• 1-5
• Cumene Hydroperoxide
• 0.5-1.5
• 2,6-di-tert-Butyl-p-Cresol
• 0.5-1.5
• And
• TABLE 2
• composition 2
• approximate %
• Ingredient
• by Wt
• METHYLENE PHENYLENE ISOCYANATE
• 35
• URETHANE PREPOLYMER
• 19-23
• MDI HOMOPOLYMER
• 12-16
• CALCIUM SODIUM ALUMINOSILICATE
• 8-12
• TALC
• 8-12
• URETHANE PREPOLYMER
• 3-7
• AMORPHOUS SILICA
• 2-6.

A method of maintaining structural integrity of an airframe while attaching a window to the airframe during manufacture of an aircraft, the method comprising the steps of not riveting a nutplate to the airframe, but instead:

• applying to a bonding surface of the nutplate an adhesive selected from the group consisting of urethane adhesives and methyl methacrylate adhesives;
• maintaining the adhesive-coated bonding surface of the nutplate adjacent an interior surface of the airframe;
• allowing the adhesive to cure;
• and
• installing a bolt through a hole of a retainer, through the hole in the airframe, and into the nutplate;
• the retainer being in contact with and securing the window to the airframe;
• wherein the adhesive has a working time of at least 15 minutes;
• and
• wherein the adhesive is selected such that the nutplate is secured by the adhesive such that:
• the bond between the nutplate and the airframe will withstand a bolt-fastening torque of at least 60 inch pounds;
• the bond between the nutplate and the airframe will withstand cycling over a range of temperatures expected to be encountered by an aircraft in flight;
• the bond between the nutplate and the airframe will withstand a push out force of at least one hundred pounds over the range of temperatures;
• and
• the bond between the nutplate and the airframe will withstand flexing of the airframe during pressurization cycles expected to be encountered by the aircraft;
• wherein the adhesive comprises the composition in Table 1:
• TABLE 1
• approximate
• Ingredient
• % by Wt
• Methyl Methacrylate
• 40-70
• Chlorosulfonated Polyethylene
• 10-30
• Acrylic Polymer - N.J.T.S. Reg No. 800941-5008P
• 5-10
• Acrylic Polymer - N.J.T.S. Reg No. 800941-5007P
• 3-7
• Maleic Acid
• 1-5
• Cumene Hydroperoxide
• 0.5-1.5
• 2,6-di-tert-Butyl-p-Cresol
• 0.5-1.5.

A method for attaching a window to an airframe, comprising:

• applying to a bonding surface of a nutplate an adhesive;
• inserting through a hole in the airframe an elastomeric fixture attached to a nut of the nutplate, and pulling the elastomeric fixture to apply tension to the elastomeric fixture to hold the adhesive-coated bonding surface of the nutplate adjacent an interior surface of the airframe;
• allowing the adhesive to cure;
• removing the elastomeric fixture from the nut of the nutplate;
• and
• installing a bolt through a hole of a retainer, through the hole in the airframe, and into the nutplate;
• the retainer being in contact with and securing the window to the airframe;
• wherein the adhesive is selected such that the nutplate is secured by the adhesive such that:
• the bond between the nutplate and the airframe will withstand a bolt-fastening torque of at least 60 inch pounds;
• the bond between the nutplate and the airframe will withstand cycling over a range of temperatures expected to be encountered by an aircraft in flight;
• the bond between the nutplate and the airframe will withstand a push out force of at least one hundred pounds over the range of temperatures expected to be encountered by the aircraft;
• and
• the bond between the nutplate and the airframe will withstand flexing of the airframe during pressurization cycles expected to be encountered by the aircraft in flight;
• and
• wherein the adhesive has a working time of at least 15 minutes;
• wherein the adhesive comprises at least one of composition 1 in Table 1 and composition 2 in Table 2:
• TABLE 1
• composition 1
• approximate %
• Ingredient
• by Wt
• Methyl Methacrylate
• 40-70
• Chlorosulfonated Polyethylene
• 10-30
• Acrylic Polymer - N.J.T.S. Reg No. 800941-5008P
• 5-10
• Acrylic Polymer - N.J.T.S. Reg No. 800941-5007P
• 3-7
• Maleic Acid
• 1-5
• Cumene Hydroperoxide
• 0.5-1.5
• 2,6-di-tert-Butyl-p-Cresol
• 0.5-1.5
• and
• TABLE 2
• composition 2
• approximate %
• Ingredient
• by Wt
• METHYLENE PHENYLENE ISOCYANATE
• 35
• URETHANE PREPOLYMER
• 19-23
• MDI HOMOPOLYMER
• 12-16
• CALCIUM SODIUM ALUMINOSILICATE
• 8-12
• TALC
• 8-12
• URETHANE PREPOLYMER
• 3-7
• AMORPHOUS SILICA
• 2-6.