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Defective Product - Stop Production

It is the task of engineers to design products and processes that create the products for the benefits of the human race. They are the people who make lives more convenient and environment friendlier for human to enjoy. They are the creative folks who make possible what were once thought to be mere fantasies. However, while engineers may endeavour to reduce the perils resulting from the application of frontier technologies, they are not always able to eliminate the dangers that come with their ingenious creation. The cause of the failure to do so does not always arise from technological incapability, but very often, it the cause is by human obstruction due to considerations such as social, cultural, and especially economic considerations.

Major technological projects such as those in the field of aerospace and aeronautics usually involve very financial cost and very tight time schedule. Correcting a major design defect can be very costly and time consuming. It may result in serious repercussion. The recent delay in the completion of Airbus A380 super jumbo jets is a good example where the delay costs the company a huge amount of money. To enable us to gain an insight into what dilemmas engineers face when they encounter design faults that are very costly and time consuming to correct, we shall discuss the case involving the Challenger Space Shuttle and the case involving the DC-10 Jumbo Jet.

The Case Involving the Challenger Space Shuttle

The main vehicle in the space shuttle is the orbiter, which is sometimes taken to be the space shuttle itself. There are three hydrogen-power rocket engines in the orbiter itself. There is also a huge cargo bay which is used for carrying payload such as the space lab or satellite that will be launched from the space shuttle. The liquid hydrogen fuel needed by the rocket engines during take-off comes from a big tank that is placed outside the orbiter. This external tank also carries the oxygen that is needed to enable the fast combustion of the rocket engines. The external storage tank will be separated from the orbiter when the hydrogen fuel is used up which takes place at about eight and a half minutes into the take-off.

The rockets in orbiter cannot provide sufficient power to send the shuttle into space because of the huge weight. The additional thrust during lift-off is provided by two external solid rocket boosters. Since the booster rockets are huge and long, they are manufactured in segments and the 5 segments are joined together at the launch site. These joints are called field joints since they are put together at the launch site. The field joints are not as sturdy as those performed in the factory and the sealing is also not as reliable. The lower performance of these field joints was apparent from the various tests. Of particular was the concern that the sealing at the joint to prevent the hot rocket air from leaking at low temperature. However, the redesigning process was slow and no new design was available.

The most significant event took place on the night of Jan 27, 1986. The Challenger space shuttle was to be launched in the morning. The maker of the solid rockets boosters, Morton-Thiokol, held a teleconference with NASA managers. The engineers at Morton-Thiokol presented their concerns about the safety of the launch. In particular, the danger due to the poor performance of the field joints under the influence of the cold weather. They recommended that the launch be postponed till the temperature rose to a more suitable level.

The NASA managers were not happy with the recommendation to postpone the launch date. There were actually many reasons. In the foremost, they thought the solid rocket boosters would be able to perform safely even at temperature below freezing point of 26 degrees Fahrenheit partly because in their design specifications, they did require that the rockets had to be able to perform safely at 31 degrees Fahrenheit. However, it was suspected that the NASA managers were keen to launch the space shuttle without any further delay because of the following three reasons:

Reason 1: Political Pressure
President Reagan was to speak on education during his State of the Union Address while the craft was to be in space. It would be a very opportune time to give his speech since one of those on board the shuttle would be a teacher.

Reason 2: Economic Pressure
NASA wanted to make the space shuttle program commercially attractive. At that time, the European Space Agency was posing too much of a competition

Reason 3: Scheduling Backlog
There had been too many delays in the past and there is a backlog of launches. In particular, the next launch was to observe Comet Halley before the Russians.

As a result of the pressure from NASA managers, Morton-Thiokol managers changed their recommendation to launch from no-launch, even though their engineers protested strongly against it.

Challenger space shuttle was launched as scheduled the next morning and it exploded, killing all the astronauts.

The Case Involving the DC-10 Aircraft

The news of the explosion of the first fully loaded DC-10 jumbo jet in 1974 over the suburbs of Paris, killing 346 people, did not surprise many engineers and managers in Convair who did the fuselage design for McDonnell Douglas.

The engineers in Convair wanted to redesign the cargo doors and to strengthen the cabin floor because they realized the defect in their design. From their calculation, they have found that the cargo door might be forced open during flight. The resulting loss of compression would lead to the failure of the passenger cabin floor where the control cables passed through. The damage to these control cables would lead to the loss of aircraft control and crash would ensue.

The top management at Convair did not inform McDonnell Douglas of the design defect because of fear of big financial cost and liabilities, as well as delay in putting the new aircraft into production.

Observations:
There are close parallels between the two cases. Both designs were known to be flawed by the engineers who tried to alert the management but the management decisions were clouded by monetary considerations which led to the eventual loss of the crafts and the lives of the occupants. In both cases, engineering hats were removed and management hats put on.

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Article Source: http://www.noviceinvesting.com/Article

Jacob Gan PhD (Michigan) has more than 20 years of teaching experience in a university and 8 years of business/industrial experience after graduation. He writes for succezz.com, JacobGan.com, JacobEducation.com, DemystifyCancer.com, understanding-orchids.com, motivate2success.com and JacobLearning.com. He hosts Jacob.TheeLearningcentre.com, an elearning portal.