Alcoa sued for millions over defective titanium parts
BOEING has sued
Alcoa for US$12m in costs for providing defective titanium aircraft parts.
The crucial titanium supports in the United States Air Force (USAF) F-22 Raptor fighter jets were found to contain a manufacturing defect.
The USAF allowed the defect to stay in the aircraft because fixing the parts would result in unacceptable costs and delays. There is no safety-of-flight issue. However, Boeing will have to carry out more frequent inspections because of the potential for catastrophic failure in flight.
Although Lockheed Martin is the prime contractor on the F-22, Boeing was the subcontractor which built the Raptor wings and aft fuselage.
From 2000 through 2005, Alcoa supplied Boeing with forged titanium parts meant to provide structural support in a section of the aft fuselage that connects the wings to the fuselage. Failure in these parts could result in the wings being ripped off in flight.
The support parts needed to be heat-treated in a furnace during manufacturing under precise conditions. This procedure would have strengthened the metal’s microstructure.
According to Boeing, Alcoa failed to follow the procedure, neglecting to add an extra 20 minutes in the furnace. This meant the forging was not properly completed. This increased the rate of crack growth, reducing the damage tolerance life of the parts.
Alcoa delivered 695 forged titanium support parts. Of the 459 forgings inspected so far, 71 were defective. Although the companies attempted to use a reheating procedure to fix the parts, the process caused metal distortion and was too costly.
The inspections and the failed reheating procedure development cost Boeing US$5.3m. In a settlement with the USAF, Boeing was required to perform $6.4m worth of extra work at no cost.
Boeing says Alcoa should reimburse these extra costs, plus legal fees. Alcoa acknowledged the defect present in the parts, but said it would defend itself in court.
14-May-2008
Related articles: