Case Study Analysis Activity Title: Name: Date: Cause(s) of Accident The Challenger shuttle crash was a crash that touched the hearts of every American due to the televised coverage and the relate ability of the crew. There was concern from the engineers that the unusually cold weather the morning of the launch could have adverse affects on the rubber O-rings that sealed the joints of the shuttles solid rocket boosters. The cold weather on the morning of January 28, 1986 caused the O-rings to tear and leak fuel from the boosters. (Dunbar B, 2005) Structural and Mechanical Factors The investigation discovered that the cold weather affected the plasticity of the O-rings that sealed the solid rocket boosters, the O-rings where not designed …show more content…
to keep their elasticity in extreme colds like that morning of the launch. After the O-rings began to fail “This first very small flame was detected on image enhanced film at 58.788 seconds into the flight. It appeared to originate at about 305 degrees around the booster circumference at or near the aft field joint” (Dunbar B, 2005). At 73 seconds in the mission the shuttle exploded killing all 7 crewmembers on board. (Dumoulin, J, 2001) Contributing Factors The contributing factors to the Challenger shuttle disaster stemmed from the O-rings not being able to handle the cold weather the morning of the launch. This was the end result of a couple of decisions made by people in key leadership positions. Their where concerns early in the preparation phase of the launch by some the engineers these concerns where brought up after the discovery of blowback coming from one of the rockets. A member of the seal team Mr. Boisjoly (1986) brought up this point: I then presented Chart 2-2 with added concerns related to the timing function. And basically on that chart, I started off talking about a lower temperature than current data base results in changing the primary O-ring sealing timing function, and I discussed the SRM-15 [Flight 51-C, January, 1985] observations, namely, the 15A [Left SRM, Flight 51-C] motor had 80 degrees arc black grease between the O-rings, and make no mistake about it, when I say black, I mean black just like coal. It was jet black. And SRM-15B [Right SRM, Flight 51-C] had a 110-degree arc of black grease between the O-rings. (NASA, n.d) In a later caucus Mr. Boisjoly was asked about what was said during the caucus, he was summarizing what was said by Mr. Mason Senior Vice President, Wasatch Operations, MTI to Mr.Lund Vice President, Engineering, MTI about their decision to launch despite none of the engineers agreeing with decisions. The biggest thing that is brought up during the interview is a comment made by Mr. Mason to Mr. Lund that is a key statement in the whole unraveling of the launch “He turned to Bob Lund and asked him to take off his engineering hat and put on his management hat” (NASA, n.d). This statement is the key step that could have completely changed the outcome of the launch. Investigation Board Findings During the investigation there was a multitude of factors that lead to the defections that sealed the fate of the Challenger.
Some of the earlier tests of the seals brought to the attention of the engineers that the seals where prone to failure when exposed to extreme temptures and due to the location of the seals not staying within the parameters of the seals would cause a catastrophic failure. Other warnings where not taken into account when the launch days drew closer, the unusually cold weather caused delays in the original launch date and the on the new launch day the temtures around the seals where estimated “to be 28degrees +/- 5 degrees Fahrenheit” (NASA, n.d). According to the NASA investigation …show more content…
(n/d): The Commission concluded that the cause of the Challenger accident was the failure of the pressure seal in the aft field joint of the right Solid Rocket Motor.
The failure was due to a faulty design unacceptably sensitive to a number of factors. (NASA, n/d) Recommendations They’re where a lot of purposed recommendations from the commission to help ensure that any future shuttle missions would not experience the same catastrophic O-ring failure like the challenger shuttle. The first recommendation was to redesign the O-ring by improving “structural capability, seal redundancy, and thermal protection” (NASA, n/d). This change would also redesign the tang and clevis of the mating points of the rocket. The redesign not only used a third O-ring seal but also a newly redesigned “O-ring seals are designed to not leak under structural deflection of twice the expected values” (NASA, n/d) Outcomes The panel has held a number of full meetings and numerous subpanel and individual member meetings, and has submitted three written status reports to the NASA Administrator. Although NASA has not yet formally responded to these status reports, actions have been taken to implement most of the committee recommendations. NASA has held several meetings with the committee to discuss and review the status of the response to the recommendations. The NRC membership and a summary of the panel responsibilities are provided in Appendix
A. In addition to the NRC panel, an advisory group of 12 experienced senior engineers from NASA and the aerospace industry are supporting the redesign team. They review the design activities and provide recommendations for major program decisions. The membership and a summary of the group's responsibilities are provided in Appendix B. References NASA (n.d.). Retrieved June 27, 2015, from http://history.nasa.gov/rogersrep/v6ch1.htm Dumoulin, J. (2001, June 12). 51-L (25). Retrieved June 26, 2015, from http://science.ksc.nasa.gov/shuttle/missions/51-l/mission-51-l.html Dunbar, B. (2005, December 5). STS-51L. Retrieved June 25, 2015, from http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/archives/sts-51L.html
R. M. Boisjoly had over a quarter-century’s experience in the aerospace industry in 1985 when he became involved in an improvement effort on the O-ring which connect segments of Morton Thiokol’s Solid Rocket Booster. This was used to bring the Space Shuttle into orbit (OEC, 2006). Morton Thiokol is an aerospace company that manufactures the solid propellant rocket motors used to launch the Challenger (Skubik). Boisjoly authored a memo to R.L. Lund, Vice President of Engineering and four others, in regards to his concerns about the flawed O-ring erosion problem. His warnings were ignored leading to the deaths of six astronauts and one social studies teacher.
On December 19th 2007, a small chemical manufacturer T2 Laboratories suffered a catastrophic failure and release while in production of a compound that is produced to increase octane in gasoline and is a common additive in fuel production Methyleclopentadienyl manganese tricarbonyl or MCMT. The failure occurred during production and resulted in the death of 4 and injuries to 32 people, 28 of which were members of the community. (CSB, 2009)
A study was done to understand the effects of thundersnow within lake effect snow events which took place between 1995 through 2007. What the study observed was that the majority of cloud to ground lightning occurred in lake effect storms during the late fall and early winter months. Twenty-seven percent of storms however occurred between the January through March period. BUFKIT was used in this study to determine the environment that would be required for lightning to occur in these storms. “The presence of the layer from -10 to -25 C within the predicted lake-effect cloud layer (lake-induced LCL to EL analyzed within BUFKIT) appears to be necessary, but not sufficient, condition for CG lightning to occur; values over 500 J/kg of lake induced CAPE much also be present for CG lightning initiation.”
The Colgan Air Flight 3407 was a very interesting case to look at. On February 12, 2009, at 10:17 pm, flight 3407 crashed at a house in New York after the pilots experience a stall. Flight 3407 was scheduled to fly from Newark, New Jersey to Buffalo, New York. The NTSB reported the cockpit voice recorder (CVR) revealed some discrepancies both pilots were experience. The first officer did not have any experience with icing condition but icing was one of the reasons the plane went into a stall. On the other hand, the captain had some experience flying in icing condition. The captain was experiencing fatigue, which indeed, made him unfit to recover from a stall. With that in mind, the Human Factor Analysis Classification System (HFACS) will give insight of some errors both pilots made.
The disaster that took place on the Ocean Ranger had a very large effect on the way Newfoundlander's feel about the gas and oil industry. The government examined the safety issues that led to this disaster and has implemented numerous changes to enhance the safety of the offshore workforce. The Newfoundland and Canadian government set up a combined royal commission to investigate the disaster of the Ocean Ranger and to provide recommendations to improve safety. Two years after the disaster, the royal commission on the Ocean Ranger disaster concluded that the deaths resulted not only from the storm and flaws in the rig's design, but also from a lack of human knowledge.
Even though there were many factors contributing to the Challenger disaster, the most important issue was the lack of an effective risk management plan. The factors leading to the Challenger disaster are:
Countless engineering disasters have occurred in this world, many civilians lost their lives due to corrupted constructions. The most fatal and deadly engineering disaster that took place in our history was the Chernobyl disaster. The Chernobyl catastrophe was a nuclear setback that happened at the Chernobyl Nuclear Power Plant in on April 26, 1986. It is seen as the most recognizable terrible nuclear power plant cataclysm ever. A nuclear crisis in one of the reactors caused a fire that sent a cluster of radioactive consequence that on the long run spread all over Europe.
is a set of O-rings that make a seal around the booster. Around the O-rings
...mpanies. The Structural Test Article simulated pressure on the vertical components during launch. After testing, Marshall concluded that the gap size was sufficient for both of the O-rings to be out of position. Again Thiokol rebutted Marshall’s claim by challenging the validity of the electrical components used to measure joint rotation. Thiokol believed that their test was superior to Marshall’s test, because it validated their conclusion. This is a fundamental problem know as experimenter’s regress. Since the true solution is unknown, the best test is the one that supports the experimenter’s view. Since this disagreement could not be solved between the two, the O-ring manufacturer was consulted. The manufacturer told the two that the O-ring was not designed for such high project specifications needed for the craft, but NASA decided to work with what they had.
On February 1, 2003, the Space Shuttle Columbia was lost due to structural failure in the left wing. On take-off, it was reported that a piece of foam insulation surrounding the shuttle fleet's 15-story external fuel tanks fell off of Columbia's tank and struck the shuttle's left wing. Extremely hot gas entered the front of Columbia's left wing just 16 seconds after the orbiter penetrated the hottest part of Earth's atmosphere on re-entry. The shuttle was equipped with hundreds of temperature sensors positioned at strategic locations. The salvaged flight recorded revealed that temperatures started to rise in the left wing leading edge a full minute before any trouble on the shuttle was noted. With a damaged left wing, Columbia started to drag left. The ships' flight control computers fought a losing battle trying to keep Columbia's nose pointed forward.
Harris, Tom. “How Building Implosions Work.” HowStuffWorks. A Discovery Co., 13 Jan. 2012. Web. 13 Jan. 2012. .
...nsion. When some one reads this article they will walk away feeling confident in the scientists in NASA and that they don’t just come up with answers to their hypothesis rather they have the ability to prove and explain how and why they came to their conclusions.
No. 4 and No. 6 reactor. An inspection found a 6’ long crack had developed and reached the
After the accident, a full-scale investigation was launched by the United States National Transportation Safety Board (NTSB). It concluded that the accident was caused by metal fatigue exacerbated by crevice corrosion, the corrosion is exacerbated by the salt water and the age of the aircraft was already 19 years old as the plane operated in a salt water environment.