Alternate Supplier Selection and Development
Dayton T. Brown, Inc has the experience to help alternate suppliers qualify their part to the Original Manufacturer or to the end user.
Typically, when a new platform is built, whether it is aircraft or ground support, the original manufacturer develops and builds the platform using selected sources or in-house manufacturing. The parts, along with the end platform are accepted by the end user and implemented in to use.
Once the new platform has been used and parts wear out, alternate source (other than OEM) are usually solicited by the end user in order to keep repair and maintenance costs down. As alternate suppliers are evaluated, the end user must be certain that the new source part lives up to the quality and durability expected by the end user.
This is where DTB can assist in making sure the alternate source part meets the standards imposed on the OEM. We have been very involved with the US ARMY since 1993 evaluating alternate source suppliers for several rotary wing aircraft through conformance (destructive) inspections as well as fatigue testing.
Our large structures lab combined with a full dimensional and metallurgical lab can efficiently evaluate parts for alternate suppliers as well and end users.
A typical Alternate Supplier program takes on the following flow after the supplier has identified a part to qualify:
- Evaluate part requirements (materials, dimensions, strength, etc)
- Create Test Plan
- Test plan approval by end user
Upon successful qualification of the part, the end user can approve the part for purchase. This, however, is not the end of the road for testing. The end user may impose a lot sampling of the part throughout the production run. Here again, Dayton T. Brown, Inc. can help the end user and supplier by making sure that the parts manufactured after qualification, meet the standards expected.
An example of how Dayton T. Brown, Inc. performed this type of work for the Navy is through the testing/re-design of the EA-6B Arresting Hook Truss. The initial purpose of this program was to extend the life of the existing inventory of EA-6B Arresting Trusses, which were out of production, while a new buy of Trusses was initiated.
In order to safely extend the life of the Truss a fatigue test with a representative loading spectrum and environment was developed by DTB. This new spectrum was based on actual flight test data using a modern Aircraft Carrier arresting engine. DTB analyzed the data and developed the new test flight load spectrum. A controlled salt water solution was applied to critical locations to simulate the actual environment for crack growth. A test fixture was designed to simulate the aircraft’s attachments and apply the loads correctly.
During testing DTB found a previously undocumented structural weak point at one of the hinge fittings thus limiting the life of the truss and resulting in no life extension. The test successfully proved that the new buy was necessary to replace the fleet assets. Further metallurgical evaluation into the failure site by our metallurgical lab confirmed areas of stress corrosion due to the overloading of the part during a heavy hook bounce on the carrier deck. At this point, the program changed from a life extension to a redesign and testing program for the redesigned truss. DTB formulated the redesign of the hinge fitting and assisted the new Truss supplier to incorporate the design changes into the new production build.
DTB performed fatigue testing on two of the new production truss assemblies with the design enhancements. The resulting data allowed for a longer life of the new asset. Significant savings were realized by the Navy due to the six fold life increase of the new Truss, which halved the required size of a new procurement.