1 CBEMS 175 SPRING QUARTER, 2017 DESIGN FAILURE INVESTIGATION Prof. J. C. Earthman FINAL PROJECT (Expert Witness Report Deadline: May 17. Contentions Deadline: May 22. Court dates: May 24, 31, June 5 and 7) We will prepare and conduct a mock trail for an imaginary civil suit concerning liability for damages sustained as a result of a failure. All students taking the course must participate as a member of one of the groups (plaintiff or defendants) involved in the trail. The Case This concerns the crash of an experimental hypersonic stealth aircraft called the "Multiple-Use Stealth Tactical Hypersonic Aerospace Vehicle" or more familiarly known in aircraft industry circles as MUSTHAV. The first prototype crashed while attempting to land at the conclusion of its first test flight, killing the civilian test pilot, Mr. Les S. Moore. An investigation by a team from the Airforce Investigative Corps (AIC) traced the primary cause of the crash to fracture of each of a set of five exhaust bleed seal rings in the aircraft's multistage propulsion system. These rings keep a set of five exhaust bleed tubes sealed against the exhaust throttle units; exhaust passing through these tubes is individually throttled and vectored in order to help steer the aircraft. Failure of the seal rings allowed the exhaust bleed tubes to loosen, leading to leakage of exhaust, a loss of directional control and thereby causing the crash. The aircraft and its propulsion system were designed by engineers at Drummin Aerospace. Mr. Moore's rather lucrative contract as a test pilot with Drummin addressed the possibility that might be injured or killed in an accident while flying experimental aircraft. The contract states that if the cause of such an accident was failure that could not have been anticipated by the manufacturer or its subcontractors, then Mr. Moore was not entitled to receive damages (the accident would be deemed an occupational hazard). However, if negligence on the part of Drummin or its subcontractors was involved, then Mr. Moore (and/or his family) was entitled to receive damages. Negligence was defined to include2 both obvious errors and also failure to use all of the relevant information that was available "to one skilled in the art". Mr. Moore's family contends that the exhaust bleed seal rings failed due to negligence on the part of all four different companies involved in designing and manufacturing the parts. These companies are: 1. Drummin Aerospace (designed the part and specified the material) 2. Marathon Manufacturing (machined the parts from barstock) 3. Anticlimax Molybdenum (supplied the material as barstock) 4. Qualcon Associates (a quality control lab that tested the material and reported to Drummin on its properties) Hence, based on the contract and on this assertion of negligence, the family contends that it is entitled to receive damages to compensate it for the loss of Mr. Moore's life and income. Accordingly, the family is suing the above four companies for fifty million dollars ($50,000,000). The purpose of the trail is to determine whether or not negligence was in fact involved. If the jury determines that negligence was involved, then it must award the plaintiff fifty million dollars damages and the jury must also decide what fraction of the fifty million dollars should be paid by each of the four companies according to their fraction of the blame. If negligence was not involved, then the jury awards nothing. The Evidence The evidence consists of the following items: 1. Portion of the failed seal ring for examination using SEM. 2. Design analysis (by Drummin) showing the loadings imposed on the part and the calculations verifying design adequacy. 3. Part drawing (by Drummin) showing the dimensions and specifying that the material should be TZM molybdenum alloy. 4. Machining schedule (by Marathon) showing the sequence of operations selected to machine the part.3 5. Material processing schedule (by Anticlimax) showing the sequence of operations selected to produce the TZM. 6. Material certification (by Qualcon) showing the measured material properties. Supporting Material To save some time and consultant fees a preliminary literature search has been performed on the subject of molybdenum alloys. Several possibly relevant items were located, consisting of the following: 1. Information on refractory metals and their alloys, excerpted from F. J. Clauss, Engineer's Guide to High-Temperature Materials. 2. Properties of molybdenum and refractory metals (taken from the ASM Metals handbook Vol. II). 3. A report that mysteriously disappeared which had something to do with a microstructural investigation of the behavior Mo alloy samples. In addition to this material, you may use and introduce as evidence any other published information. However, if you borrow such publications from a library or a UCI faculty member's collection, then one week before the first trail (in class on Monday, May 17th) you must inform the other groups of the materials you have borrowed and give them an opportunity to use it also. Failure to follow this procedure will result in such material being ruled as inadmissible as evidence. Trial Preparation Each member of the course will represent as an attorney or serve as the expert witness for one of the four parties to the lawsuit. The expert witnesses will provide a failure analysis report that will be handed in on May 17th. As many as four attorneys will present an opening statement that is in the best interest of their client company. Preparation for the trial should be divided as evenly as possible between the members of each group. Each party of the lawsuit will be able to examine one portion of the failed ring using SEM for one hour only. EDS may also be used if deemed appropriate. After performing this task and reviewing the other evidence obtained, the expert witnesses in each group will prepare a five page signed report for the confidential4 use of the attorneys in their team that will be handed in at beginning of the trial. This report will remain confidential during the trials. Each party should form opinions as to the cause of the strainer failure and the degree of negligence (if any) and liability of each party. Based on these opinions, each group should prepare a 15-minute opening statement. You are free to discuss the case with anyone, but no second-hand testimony will be allowed (i.e. you must