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PROGRAM: Aero-Structure Reconstruction

PRODUCT: Leading Edge Flaps

PROBLEM: Leading Edge Flaps on Northrop F-5 are subjected to extensive wear and corrosion due to the extended life extension of the aircraft. Costs for replacing the complete aero-structure are very high and deliver times are extensive.

SOLUTION: The Northrop F-5 Leading Edge Flaps; p/n’s 14-27200-509 / -510, are subject to cracking and corrosion at the leading edge of the flap, causing material loss that exceeds the TO limits in T.O. 1F5E-3 Sect. II. There is often corrosion in areas of the fasteners as well. When Maximum Corrosion Removal Limits are exceeded, the aircraft should not be flown.
The reskinning and reconstruction process offers significant savings in both cost and delivery time. Flaps can be re-skinned with new leading edge skins and returned to service in under 150 days. Using special techniques, our technicians remove the leading edge skins and perform inspections on all of the components of the leading edge aero-structure. All of the substructure parts go through dimensional and NDI inspections I/A/W OEM Specifications.

The Process:
The procedure involves carefully removing the LE Skin from the frame assembly. Using specially designed tooling fixtures, the LE Flap is secured in such a way as to ensure the LE skin can be removed without disrupting the components pf the LE aero-structure. The special tooling fixtures hold all of the component parts of the LE assembly in place. Photogrammetry coupled with Surface Software (CAD based 3D software) captures all of the locations of the fastener holes and the three dimensional location of all the piece parts. Using the EDM Drill, all of the fasteners are removed without any damage to the component parts of the aero-structure. Once the corroded, out of limits old LE skin is removed, all of the piece parts are disassembled. The Surface Software has captured all of the locations and the exact position of each piece part so that the entire LE Flap can be reassembled after inspections and re-processing are completed.


Complete visual inspection is performed followed by a close tolerance CMM dimensional inspection. All of the hole diameters are measured to ensure hole sizes meet specifications. The entire assembly is checked for dimensional conformance to the drawings specifications.

Reprocessing Parts:
All of the piece parts are media blasted (cleaned, removing all paint and coatings). Each part goes through NDI inspection, meeting all specifications for inspection. Piece parts that pass dimensional and NDI inspection are fresh anodized and primed per specifications. Any piece parts that do not pass dimensional and NDI inspection are replaced with new piece parts.

Basic Repair Program:
The Basic Repair includes the installation of new Leading Edge Skins, Part Numbers 14-27201-9 and -10, with all new hardware, bushings, shims, and fasteners. All of the component parts are NDI tested and refinished I/A/W OEM specification. Pricing for the Basic Repair Program starts at $49,645.00 with delivery in 150 days.

Recommended Repair Plan (RRP):
After all of the components are disassembled, they are visually inspected for corrosion, dimensionally checked, including fastener hole diameters, and prepared for NDI inspection. The Recommended Repair Plan (RRP) lists any components or subcomponents that have not passed dimensional and/or NDI inspection. The report lists the parts that are recommended be replaced along with the costs and delivery time. Upon customer approval of the Recommended Repair Plan (RRP), the reskinning and reconstruction of the LE Flaps is performed. A Price List of the component parts is attached to this Proposal.

Program Benefits:
Benefits of the Program include significantly reduced costs over new manufacture and 3-4 times faster delivery allowing our customers to have their aircraft returned to service faster and at less cost.

Launch Project

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