MGMT 580 Week 4

MGMT 580 FINAL PROJECTCesar A. Marrero1AgendaIntroductionPopularity of the Boeing 737Reliability ProgramFailures of the Boeing 737Evaluation: Defective Wiring (TWA Flight 800)ConclusionIntroductionBoeing 737 the workhorse for low-fare airlines around the worldEasier and less expensive to maintainFewer parts than older modelsQuick turnaround at the terminals

The Boeing 737 has become the workhorse for low-fare airline carriers around the world, comprising over 90 percent of their fleets. This airframe, in service since 1965, is easier and less expensive to maintain; due to the airplanes simple design and low stance on the ramp, loading and maintenance are much easier than other airframes. The 737 improves reliability and maintainability due to having fewer parts than older models. Baggage can be loaded from the ground, allowing for last-minute bag additions, and quick turnarounds allow carriers to keep the aircraft in the air earning revenue instead of sitting idle on the ground. 3Boeing 737 PopularityOver 7,500 aircraft delivered to dateRecord-breaking orders of any model in a single year1,124 net orders of the next-generation version (models 700, 800, and 900) in 2012914 orders for the 737 MAX versionThe popularity and reliability of the Boeing 737 has helped the company deliver more than 7,500 aircraft, to include more than 4,400 of the Next-Generation version (models 700, 800 and 900) through April 2013. The 737 program broke the record for orders for any Boeing model in a single year, accumulating 1,124 net orders in 2012. The 737 MAX - which brings the best of future engine technologies to the record-selling 737 - accounted for 914 of those orders, bringing total orders to date to 1,235. In addition, the Next-Generation 737 set a new single-year record with 415 deliveries to customers worldwide. The 737 program also celebrated its 10,000th order in 2012.4Reliability ProgramEntire SystemCommon components reused in all airframesUnchanged fuselageChanges primarily to wing structure and enginesAirframe is quite cost-efficientRedesigning fuselage would not provide much improvementIncreased costs with two separate production lines

The success of the Boeing 737 airframe can be attributed in a large part to how the company has engineered common components that are reused in all of their airframes -- in effect, they do not have to re-invent the wheel for each new system. For example, the fuselage of the 737 has remained mostly unchanged for all iterations, with wing structure and engine changes affecting most of the major overhauls, aimed primarily towards fuel efficiency and improved maintenance. The common fuselage and components found within, such as the cockpit and avionics, are an essential reason why maintaining the airframe is so cost efficient with this particular airframe. Staying with a largely unchanged body was as much a financial decision as a technical one, for two reasons: a) the redesign of a new fuselage would not have provided much improvement in operational efficiencies, and b) a completely new airplane would have increased costs in the legacy system since the old production line would become obsolete. 5Reliability ProgramHumans in the SystemCommonality of airframes promotes familiarityTraining costs are significantly reducedEmployees use a common set of tools and procedures

Commonality within the Boeing airframes promotes familiarity with all their users, such as the pilots and maintenance personnel. Training costs are significantly reduced, since there is no need to reacquaint system users with each change in the airframe. For example, the aircrew of any Boeing aircraft can enter the cockpit and immediately take control, because all of the components are identical, requiring no additional training. This attention applies equally to the production line, where employees use a common set of tools and procedures that ensure familiarity and much less time spent on training.6Reliability ProgramMaintenance of the SystemInterchangeable partsStandard technical documentationLongevity effortsMaintenance crews are also at an advantage, thanks to Boeings approach to the use of interchangeable parts and standard technical documentation amongst all components, subassemblies and subsystems. Currently, the rule of thumb in the airline industry is that maintenance costs double once an aircraft reaches 25 years in service, due to the amount of wear and tear inflicted on the airframe. However, maintainers of the 737 systematically inspect, clean, repair, reinforce, rebolt and reseal the aircraft, thus exceeding original factory standards and protecting them from deterioration, allowing the aircraft to last indefinitely.

7Reliability ProgramSimplicity of DesignGreater turnarounds for airline carriersMaximize the use of their fleetLow stance on the rampEasier to maintain and loadServicing can be done at ground levelBaggage can be loaded from the groundLast minute cargo/luggage additions

The design of the Boeing 737 provides for greater turnarounds that allow carriers to maximize the use of their fleet, thus keeping them in the air (and earning revenue) instead of sitting idle on the ground. Because the airplane can be turned around at the gate so quickly, airlines can get back on schedule if they fall behind for any myriad of reasons (Boeing, 2013). The aircraft has a low stance on the ramp, making it easier to maintain and load. In addition, most of the servicing can be done at ground level, including engine maintenance, and newer versions of the 737s even have fewer parts, and since baggage can be loaded from the ground, this gives the carriers greater allowance for last-minute cargo/luggage additions.8Reliability ProgramRedundant and fail-safe featuresTwo engines per aircraft, even though only one is needed to flyTwo electrical systemsTwo fuel systemsEmergency Oxygen systemTriple Rudder systemRedundancy is an aerospace design principle in which duplicate systems are used to prevent overall failure if one part is damaged, and the 737 provides several redundant systems: there are two engines in each aircraft (even though it only needs one to fly), two electrical systems, two fuel systems, an emergency oxygen system, and a triple rudder system that allows normal operation if it becomes jammed. Boeing performs a number of redundancy checks on all their critical systems, following aviation safety guidance and strict quality control standards. 9Reliability ProgramManufacturing Methods and Purchasing RequirementsAssembly line production, similar to the automotive industryAccelerated productionReduced production costsFewer order backlogs and customer waiting timesTheir production method is based on a moving assembly line, which accelerates production, reduces production costs, and lessens order backlogs & customer waiting times. The assembly line moves continuously at a rate of 2 inches per minute, and there are even timelines painted on the floor that helps workers gauge the progress of manufacturing. 10Reliability ProgramMaintenance of complete product or system performance recordsProduction and maintenance logsRecords failures, replacements, repairs, warnings, field tests, and operating conditionsInfluences changes in the airframeImproves manufacturing methodsModifies quality checksIdentifies most reliable componentsExtensive field testing before components are fieldedThe airline industry depends heavily on the production and maintenance logs collected throughout the lifespan of an aircraft, to include failures, replacements, repairs, warnings, field tests, and operating conditions. The data in these logs greatly influence changes in the airframe, improve manufacturing methods, modify quality checks, and identifies the most reliable components. Before a component is fielded on any airframe, Boeing performs extensive field testing that pushes the boundaries of the components intended design. 11Reliability ProgramCommunicationValuable collaboration between customers, chief mechanics, and field service repsEfforts ensure new version of 737 continues the trend of simplicity, reliability and low cost.Airlines can choose a version of 737 with latest cockpit displays or commonality with older modelsBoeings customers, chief mechanics, and field service representatives participated in the development of the Next-Generation 737 models, and they ensured the new version of the airframe included advanced technology that allows for simplicity, reliability and low cost, while still providing flight-deck commonality with earlier 737s. Thanks to this level of collaboration, Airlines can now choose a version of the 737 that gives their flight crews either the latest display format (common with the Boeing 777), or opt for data format commonality with earlier 737 models.12Failures of the Boeing 737Events influenced dramatic changes in the inspection and maintenance processTWA Flight 800 Exploded, killing all on boardSouthwest Flight 812 Peeled exterior skinThe history of the Boeing 737 does include certain failures in the last 20 years that strongly influenced dramatic changes in the procedures implemented for aircraft inspections and maintenance. Two specific instances include the explosion of TWA Flight 800 in 1996, and the loss of cabin pressure of Southwest Flight 812 in 2011. Both of these incidents ultimately influenced how maintenance crews perform periodic inspections on the aging 737 airframe. 13TWA Flight 800Exploded 12 minutes after take offBoeing Model 747, not 737230 on board killedCause determined to be faulty wiringSpark caused ignition of fuel fumesFAA ordered Boeing to inspect all airframes, especially the older 737 model

On 17 July 1996, TWA Flight 800 exploded 12 minutes after take-off, killing all 230 people on-board. The cause was determined to be faulty wiring that caused a spark that ignited fuel vapors adjacent to a fuel tank. During the disaster investigation, the Federal Aviation Administration ordered Boeing to inspect the entire fleet of 737s, even though TWA Flight 800 was a newer 747 model. The reason for this order was primarily due to there being over 3,000 of the aging first-generation 737 models still in service, and the concern that they would all be vulnerable to the same faulty wiring found in the 747 models that caused the disaster of TWA Flight 800 (Summers, 2010, pg. 367). Even though the 737 had a proven record of high reliability, the concern was the fact that the airframe was not designed for such extended longevity after leaving the production line.14Southwest Airlines Flight 812Loss of cabin pressure, caused crew to perform emergency landingCause determined to be manufacturing flaws on the fuselage skinRivet joints not aligned or overlapped, causing fatigue on external skinSkin peeled off, causing a rapid loss of cabin pressureNot first time skin peeled-offOn 1 April 2011, Southwest Airlines Flight 812 was forced to perform an emergency landing after a portion of the exterior skin above the passenger cabin peeled-off and caused a loss of cabin pressure. The cause was determined to be serious manufacturing flaws. Forty-two rivet holes at joints where the fuselage skin overlapped, called lap joints, were so far out of alignment that the lower holes had become oval, not round, causing fatigue cracks, and paint had leaked from the outer skin into the joints. (Irving, 2012). This instance of cabin loss wasnt the first one for the 737 airframe. In 1981 a Taiwanese airline encountered sudden cabin decompression that caused the aircraft to plunge 22,000 feet, killing all 110 on-board. In 1988, Aloha Airlines suddenly lost an 8-by-12 foot section of the cabin roof, with one flight attendant being expelled from the aircraft to her death. On both of these incidents, humidity was the common factor that instigated the failure.15Evaluation of Defective WiringCause and effect diagram:

Aircraft ExplodesPeopleMachinery / EquipmentMaterialsMethodsDifferent fuel mixtureFailure to detect defective cablesSubstandard cablesInsufficient quality controlMissing inspection stepsInexperienced maintainersInsufficient testing toolsInadequate testing toolsAnalyzing TWA Flight 800, one can think of several possible reasons that could cause the explosion. The following is a simple Cause & Effect diagram that explains what could have caused the incident.16Machinery / EquipmentInsufficient testing toolsNO tools available to detect fuel leaks

Inadequate testing toolsNO tools to detect electrical shortages

Insufficient testing tools maintainers might not have tools that can detect possible fuel leaks surrounding the electrical wiring in the fuselage, which can be resolved with additional sensors surrounding the fuel cells.

Inadequate testing tools maintainers might have tools to detect possible fuel leaks, but not tools that can also detect electrical shortages with accuracy, which can be resolved by providing diagnostic equipment that analyzes current strength and fluctuations.

17MethodsMissing inspection stepsNO instructions on how to inspect for fuel leaks around electrical wiring

Insufficient quality controlNO formal QC oversight when inspecting the areas where fuel cells and electrical wiring are combinedMissing inspection steps maintainers were not instructed to inspect for fuel leaks surrounding the areas that are in contact with electrical wiring, which can be resolved by adding these steps into the daily inspection procedures.

Insufficient quality control maintainers had no formal QC oversight when inspecting the areas where fuel cells and electrical wiring are combined, which can be resolved by including additional QC steps during daily inspections and periodic maintenance.

18PeopleFailure to detect defective cablesNO trainingUnable to physically view defective cables

Inexperienced maintainersNO experienced workers/mentorsFailure to detect defective cables maintainers were untrained or unable to physically view the defective cables, which can be resolved by increase training and alternate access methods to the cabling system.

Inexperienced maintainers theres a lack of experienced workers that would have identified possible problems with the aircraft, which can be resolved by increasing on-the-job training and mentoring by veteran maintainers.

19MaterialsSubstandard cablesOutsourced cables delivered by sub-contractors

Different fuel mixturesLack of standard fuel operations at airfields world-wideSubstandard cables this can be caused by sub-contracting efforts made by Boeing to reduce the cost of parts, which can be resolved by increased pre-inspection of electric wiring assemblies prior to installation, or looking for alternate sub-contractors that can deliver wiring with heightened quality standards.

Different fuel mixture although most aircraft manufacturers provide specific guidance regarding the fuel used in their airframe, fuel operations at the different airfields might not be able to provide the exact fuel mixture required. This can be resolved by standardizing fuel mixtures worldwide.

20Corrective ActionsFAA ensure corrective actions are complied withBoeing ensures employees receive immediate maintenance noticesBoeing consider redesigning electrical wiring near fuel systemsBoeing consider improving fuel leak detectors1) The Federal Aviation Administration should ensure the corrective actions taken by Boeing are being accurately complied with, and that they are properly recorded in all future production and maintenance logs.

2) Boeing should ensure that their production and maintenance employees receive high-priority notices that immediately outline changes in any installation or repairs of both fuel cells and adjoining electrical wiring.

3) Boeing must consider redesigning the electrical wiring that has the possibility of being placed near locations that might become flooded with fuel or fuel fumes, to include the possibility of optical alternatives (fiber optics) for communication cabling.

4) Boeing must consider improving sensors capable of detecting possible fuel leaks or fumes wherever there are electric wiring installed, along with possible in-flight mitigation mechanisms, such as non-flammable foam deployment systems.

21ConclusionReliability, or quality over the long term, is the availability of a product to perform its intended function over a period of time and under prescribed environmental conditions. (Summers, 2010). Based on this definition, the Boeing 737 has exceeded these conditionsSurpassed their intended function by extending its lifespan beyond the prescribed maximum of 75,000 flights. Reliability, or quality over the long term, is the availability of a product to perform its intended function over a period of time and under prescribed environmental conditions. (Summers, 2010). Based on this definition, the Boeing 737 has exceeded these conditions, proving that an airframe can surpass their intended function by extending its lifespan beyond the prescribed maximum of 75,000 flights. They have implemented a reliability program that exceeds the standards set for the airframes components, subsystems and subassemblies, while providing a collection of reusable airframes that have become the preferred plane for low-fare airlines all over the world. They have learned from their mistakes, studied three decades of collected logs, polished their production and maintenance functions, and ensured the long-term endurance and legacy of this widely-used airframe for years to come.

22ReferencesBoeing Website (2013). The Boeing Next-Generation 737 Family -- Productive, Progressive, Flexible, Familiar. Retrieved August 16, 2013 from http://www.boeing.com/boeing/commercial/737family/background.pageDummeyer, D. (2013). Boeing Quarterly Reports (2Q13). Retrieved August 16, 2013 from http://www.boeing.com/commercial/aeromagazine/articles/2013_q2/pdf/AERO_2013q2.pdfBrady, C. (1999). Boeing 737 Production. Retrieved August 15, 2013 from http://www.b737.org.uk/production.htmIrving, C. (2012). Is Boeings 737 an Airplane Prone to Problems? - Newsweek. Retrieved August 17, 2013 from Newsweek Magazine at http://www.thedailybeast.com/newsweek/2012/03/19/is-boeing-s-737-an-airplane-prone-to-problems.htmlSpicer, K., Angers, S. (2002). Boeing: The Secret Behind High Profits at Low-Fare Airlines. Retrieved August 15, 2013 from Boeing website: http://www.boeing.com/commercial/news/feature/profit.html Summers, D. (2010). Quality. New Jersey: Prentice Hall