Sealant having fireworthy properties for use with aircraft parts

A device for providing an environmental seal to an aircraft assembly comprising a first part and a spaced apart second part, the two parts forming a gap, the device comprising:

• a sealant comprising a skeleton and a body encapsulating the skeleton, wherein the body is comprised of a cured polyurethane gel, resulting from a mix of a polyol and isocyanate, the sealant having fireworthiness properties and passing the following tests:
• wherein the sealant has toxicity limits of less than about:
• 150 PPM HCN, 1000 PPM CO, 100 PPM NO/NO2, 100 PPM SO2, 100 PPM HF, and 150 PPM HCl under AITM 3-0005, Issue 2;
• wherein the sealant passes 12 second vertical burn test according to 14 CFR, Part 25—Subpart D, § 25.853(a) compartment interiors;
• wherein the sealant has a smoke density of Ds maximum at about 4.0 min. of under 200 AITM2-0007A, Issue 3;
• wherein the skeleton is comprised of a nylon or fiberglass mesh having a thickness less than about 0.033″;
• and
• the body having a tackiness of between 5 and 50 psi;
• and
• wherein the volume of gel/skeleton is in the range of about 3/1 to 7/1.

A method for releasably, environmentally sealing a pair of opposing, gap forming, fastener engaging surfaces of aircraft parts, the method comprising the steps of:

• providing an adhesive-free elastomeric, tacky sealant having a layer of polyurethane gel encapsulating a skeleton, the sealant having fireworthiness properties;
• placing the sealant in the gap between the surfaces;
• and
• compressing the opposing surfaces by tightening the fasteners, and closing the gap contacting the sealant, thereby providing a substantially fluid and air tight seal between the opposed mating surfaces with the sealant substantially filling the gap;
• wherein the sealant has a smoke density of 200 maximum at 4.0 min. under 200 AITM2-0007A, Issue 3;
• wherein the sealant has toxicity limits of less than about:
• 150 PPM HCN, 1000 PPM CO, 100 PPM NO/NO2, 100 PPM SO2, 100 PPM HF, and 150 PPM HCl under AITM 3-0005, Issue 2;
• and
• wherein the sealant passes 12 second vertical burn test according to 14 CFR, Part 25—Subpart D, § 25.853(a) compartment interiors.