The present disclosure relates to a fireshield, and more particularly to an aircraft nacelle fireshield.
Fireshields often line sections of gas turbine engine nacelle structures such as thrust reverse sections to provide thermal protection. Fireshields are subject to high temperatures and eventually may require replacement.
Fireseal fastener hoods are welded thermal protection covers for fasteners and fastener holes by which the fireshield is attached to engine nacelle structure. Fireseal fastener hoods typically extend outward from the fireshield and may be particular susceptible to handling damage which in turn may necessitate replacement of the entire fireshield because welding a replacement hood may damage an underlying substrate.
A method of repairing a fireshield fastener hood according to an exemplary aspect of the present disclosure includes bonding a cover to a substrate.
A fireshield fastener hood according to an exemplary aspect of the present disclosure includes a cover bonded to a substrate.
A fireshield according to an exemplary aspect of the present disclosure includes a fireshield fastener hood welded to a fireshield at a hinge, the fireshield fastener hood includes a cover bonded to a substrate.
Various features will become apparent to those skilled in the art from the following detailed description of the disclosed non-limiting embodiment. The drawings that accompany the detailed description can be briefly described as follows:
With reference to
The fireshield 26 is mounted to a multiple of studs 28 which extend from the cowl section 24. The studs 28 extend through the fireshield 26 to receive a fastener 30 such as a nut to retain the fireshield 26 to the cowl section 24. The extended stud 28 and fastener 30 are protected by a movable fireshield fastener hood 32 (
With reference to
The hinge 42 is a folded section of the substrate 44 which may be tack welded to the fireshield 26 to permit the fireshield fastener hood 32 to move relative thereto. The tab 40 extends from the platform 38 for receipt into a retainer 50 in the fireshield 26 to close the fireshield fastener hood 32 over the stud 28 and fastener 30. To access the stud 28 and fastener 30, the tab 40 is slipped out from under the retainer 50 and the fireshield fastener hood 32 is pivoted upon the hinge 42.
Oftentimes the substrate 44 may crack, tear, or otherwise be damaged in a manner which is repairable by the method disclosed herein (
With Reference to
Step 102 of the repair may include removal of the tab 40 (
With Reference to
The cover 52 may be manufactured of an AISI 300 Series Stainless Steel alloy which is approximately the same thickness as the hood 32. That is, the cover 52 may be manufactured from a similar material as the substrate 44. The cover 52 may also form a replacement tab 40′. That is, the cover 52 forms a double layer of material over the hood 36 and the platform 38 but a single layer to define the replacement tab 40′ as only a single layer thickness would fit within the retainer 50 (
Step 108 of the repair includes trimming the cover 52 to cover the substrate except the hinge 42. The trimming should include additional material to wrap around the edges. (
In step 110 the cover 52 is cleaned.
In step 112, a layer of primer 54 is applied to the mating surface of the cover 52, and the substrate 44. The primer 54 may be a silicone primer compatible with the fire wall sealant 56, such as DAPCO 1-100 manufactured by D Aircraft Products Inc. of California, USA.
With reference to
In step 116, the cover 52 is then pressed onto the layer of sealant 56 on the substrate 44. The cover 52 is wrapped over the edges of the substrate 44 (
In step 118, excess sealant is removed before curing cycle (Step 122).
In step 120, the cover 52 is edge sealed (step 120). Sealant squeeze out is required all around the cover 52 (
In step 122, the sealant 56 is cured.
In step 124, the cover 52 is inspected for complete sealing and attachment.
In step 126, the replacement tab 40′ is inserted into the retainer 50 (
The repair method covers the damaged area with a new thermal barrier cover 52 bonded with the sealant 56. The method allows for large scale production or repair.
It should be understood that relative positional terms such as “forward,” “aft,” “upper,” “lower,” “above,” “below,” and the like are with reference to the normal operational attitude of the vehicle and should not be considered otherwise limiting.
It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should also be understood that although a particular component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit herefrom.
Although particular step sequences are shown, described, and claimed, it should be understood that steps may be performed in any order, separated or combined unless otherwise indicated and will still benefit from the present disclosure.
The foregoing description is exemplary rather than defined by the limitations within. Various non-limiting embodiments are disclosed herein, however, one of ordinary skill in the art would recognize that various modifications and variations in light of the above teachings will fall within the scope of the appended claims. It is therefore to be understood that within the scope of the appended claims, the disclosure may be practiced other than as specifically described. For that reason the appended claims should be studied to determine true scope and content.
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Entry |
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DAPCO 18-4 Product Description. Western American Specialties. http://www.westernamspec.com/products/adhesive/dapco-18-4/39852. |
Number | Date | Country | |
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20120328427 A1 | Dec 2012 | US |