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111-438: The DC-9 is powered by two rear-mounted Pratt & Whitney JT8D low-bypass turbofan engines under a T-tail for a cleaner wing aerodynamic. It has a two-person flight deck and built-in airstairs to better suit smaller airports. The Series 10 aircraft are 104 ft (32 m) long for typically 90 coach seats. The Series 30, stretched by 15 ft (4.5 m) to seat 115 in economy, has a larger wing and more powerful engines for

222-649: A great circle route. Hence, in case of an engine failure in a twinjet (like Boeing 777 ), the twin-jet could make emergency landings in fields in Canada , Alaska , eastern Russia , Greenland , Iceland , or the British Isles . The Boeing 777 has also been approved by the Federal Aviation Administration for flights between North America and Hawaii , which is the world's longest regular airline route with no diversion airports along

333-518: A podded engine usually mounted beneath, or occasionally above or within, each wing. Most notable examples of such a configuration are the Boeing 737 and Airbus A320 . The second has one engine mounted on each side of the rear fuselage, close to its empennage , used by many business jets , although some airliners like the Fokker 70 , Douglas DC-9 and COMAC ARJ21 utilise such a design as well. In

444-706: A professional role , a risk manager will "oversee the organization's comprehensive insurance and risk management program, assessing and identifying risks that could impede the reputation, safety, security, or financial success of the organization", and then develop plans to minimize and / or mitigate any negative (financial) outcomes. Risk Analysts support the technical side of the organization's risk management approach: once risk data has been compiled and evaluated, analysts share their findings with their managers, who use those insights to decide among possible solutions. See also Chief Risk Officer , internal audit , and Financial risk management § Corporate finance . Risk

555-590: A property or business to avoid legal liability is one such example. Avoiding airplane flights for fear of hijacking . Avoidance may seem like the answer to all risks, but avoiding risks also means losing out on the potential gain that accepting (retaining) the risk may have allowed. Not entering a business to avoid the risk of loss also avoids the possibility of earning profits. Increasing risk regulation in hospitals has led to avoidance of treating higher risk conditions, in favor of patients presenting with lower risk. Risk reduction or "optimization" involves reducing

666-413: A "transfer of risk." However, technically speaking, the buyer of the contract generally retains legal responsibility for the losses "transferred", meaning that insurance may be described more accurately as a post-event compensatory mechanism. For example, a personal injuries insurance policy does not transfer the risk of a car accident to the insurance company. The risk still lies with the policyholder namely

777-416: A balance between negative risk and the benefit of the operation or activity; and between risk reduction and effort applied. By effectively applying Health, Safety and Environment (HSE) management standards, organizations can achieve tolerable levels of residual risk . Modern software development methodologies reduce risk by developing and delivering software incrementally. Early methodologies suffered from

888-517: A company may outsource only its software development, the manufacturing of hard goods, or customer support needs to another company, while handling the business management itself. This way, the company can concentrate more on business development without having to worry as much about the manufacturing process, managing the development team, or finding a physical location for a center. Also, implanting controls can also be an option in reducing risk. Controls that either detect causes of unwanted events prior to

999-879: A higher maximum takeoff weight (MTOW); it first flew in August 1966 and entered service in February 1967. The Series 20 has the Series 10 fuselage, more powerful engines, and the Series 30's improved wings; it first flew in September 1968 and entered service in January 1969. The Series 40 was further lengthened by 6 ft (2 m) for 125 passengers, and the final DC-9-50 series first flew in 1974, stretched again by 8 ft (2.5 m) for 135 passengers. When deliveries ended in October 1982, 976 had been built. Smaller variants competed with

1110-484: A higher probability but lower loss, versus a risk with higher loss but lower probability. Opportunity cost represents a unique challenge for risk managers. It can be difficult to determine when to put resources toward risk management and when to use those resources elsewhere. Again, ideal risk management optimises resource usage (spending, manpower etc), and also minimizes the negative effects of risks. Opportunities first appear in academic research or management books in

1221-484: A maximum weight of 82,000 lb (37,000 kg). The Series 10 was similar in size and configuration to the BAC One-Eleven and featured a T-tail and rear-mounted engines. Power was provided by a pair of 12,500  lbf (56  kN ) JT8D-5 or 14,000 lbf (62 kN) JT8D-7 engines. A total of 137 were built. Delta Air Lines was the initial operator. The Series 10 was produced in two main subvariants,

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1332-417: A schedule for control implementation and responsible persons for those actions. There are four basic steps of risk management plan, which are threat assessment, vulnerability assessment, impact assessment and risk mitigation strategy development. According to ISO/IEC 27001 , the stage immediately after completion of the risk assessment phase consists of preparing a Risk Treatment Plan, which should document

1443-408: A specified distance from an available diversion airport. Overwater flights near diversion airports need not be ETOPS/LROPS-compliant. Since the 1990s, airlines have increasingly turned from four-engine or three-engine airliners to twin-engine airliners to operate transatlantic and transpacific flight routes. On a nonstop flight from America to Asia or Europe, the long-range aircraft usually follows

1554-541: A trijet aircraft) and Boeing worked on new widebody twinjet designs that would become the Airbus A330 and Boeing 777 , respectively. The MD-11's long range advantage was brief as it was soon nullified by the Airbus A330-300 and the extended-range Boeing 767-300ER and Boeing 777-200ER. The Airbus A320 twinjet stands out as the most produced jet airliner. The Boeing 777X is the world's largest twinjet, and

1665-607: A two-year contract with the French aeronautics company Sud Aviation for technical cooperation; under the terms of this contract, Douglas would market and support the Sud Aviation Caravelle and produce a licensed version if sufficient orders were forthcoming from airlines. However, none were ever ordered from the company, leading to Douglas returning to its design studies after the co-operation deal expired. In 1962, design studies were underway into what would become

1776-477: Is ISO Guide 31073:2022 , "Risk management — Vocabulary". Ideally in risk management, a prioritization process is followed. Whereby the risks with the greatest loss (or impact) and the greatest probability of occurring are handled first. Risks with lower probability of occurrence and lower loss are handled in descending order. In practice the process of assessing overall risk can be tricky, and organisation has to balance resources used to mitigate between risks with

1887-461: Is 600 nmi (1,100 km; 690 mi), increasing to 1,450 nmi (2,690 km; 1,670 mi) with full fuel. The aircraft is fitted with a passenger door in the port forward fuselage, and a service door/emergency exit is installed opposite. An airstair installed below the front passenger door was available as an option as was an airstair in the tailcone. This also doubled as an emergency exit. Available with either two or four overwing exits,

1998-500: Is 81,700 lb (37,100 kg). The Series 14 has a fuel capacity of 3,693 US gallons (with the 907 US gal centre section fuel). The Series 15, certificated on January 21, 1966, is physically identical to the Series 14 but has an increased MTOW of 90,700 lb (41,100 kg). Typical range with 50 passengers and baggage is 950 nautical miles [nmi] (1,760 km; 1,090 mi), increasing to 1,278 nmi (2,367 km; 1,471 mi) at long-range cruise. Range with maximum payload

2109-571: Is a jet aircraft powered by two engines . A twinjet is able to fly well enough to land with a single working engine, making it safer than a single-engine aircraft in the event of failure of an engine. Fuel efficiency of a twinjet is better than that of aircraft with more engines. These considerations have led to the widespread use of aircraft of all types with twin engines, including airliners , fixed-wing military aircraft , and others. There are three common configurations of twinjet aircraft. The first, common on large aircraft such as airliners, has

2220-533: Is a further lengthened version. With a 6 ft 6 in (2 m) longer fuselage, accommodation was up to 125 passengers. The Series 40 was fitted with Pratt & Whitney engines with thrust of 14,500 to 16,000 lbf (64 to 71 kN). A total of 71 were produced. The variant first entered service with Scandinavian Airlines System (SAS) in March 1968. Its unit cost was US$ 5.2 million (1972) (equivalent to US$ 28.73 million in 2023) . The Series 50

2331-561: Is a result of the rear-mounted engines. The DC-9 series, the first generation of the DC-9 family, includes five members or variants and 10 subvariants, which are the production versions (types). Their designations use the Series (DC-9-) prefix followed by a two-digit numbering with the same first digit and the second digit being a zero for variant names and a nonzero for version/type designations. The first variant, Series 10 (DC-9-10), has four versions (Series 11, Series 12, Series 14 and Series 15);

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2442-427: Is a viable strategy for small risks where the cost of insuring against the risk would be greater over time than the total losses sustained. All risks that are not avoided or transferred are retained by default. This includes risks that are so large or catastrophic that either they cannot be insured against or the premiums would be infeasible. War is an example since most property and risks are not insured against war, so

2553-511: Is defined as the possibility that an event will occur that adversely affects the achievement of an objective. Uncertainty, therefore, is a key aspect of risk. Risk management appears in scientific and management literature since the 1920s. It became a formal science in the 1950s, when articles and books with "risk management" in the title also appear in library searches. Most of research was initially related to finance and insurance. One popular standard clarifying vocabulary used in risk management

2664-636: Is derived from the DC-9 family. The ARJ21 is built with manufacturing tooling from the MD-90 Trunkliner program. As a consequence, it has the same fuselage cross-section, nose profile, and tail. The DC-9 was designed for short to medium-haul routes, often to smaller airports with shorter runways and less ground infrastructure than the major airports being served by larger airliners like the Boeing 707 and Douglas DC-8, where accessibility and short-field characteristics were needed. The DC-9's takeoff weight

2775-451: Is determining the rate of occurrence since statistical information is not available on all kinds of past incidents and is particularly scanty in the case of catastrophic events, simply because of their infrequency. Furthermore, evaluating the severity of the consequences (impact) is often quite difficult for intangible assets. Asset valuation is another question that needs to be addressed. Thus, best educated opinions and available statistics are

2886-531: Is known, the events that a source may trigger or the events that can lead to a problem can be investigated. For example: stakeholders withdrawing during a project may endanger funding of the project; confidential information may be stolen by employees even within a closed network; lightning striking an aircraft during takeoff may make all people on board immediate casualties. The chosen method of identifying risks may depend on culture, industry practice and compliance. The identification methods are formed by templates or

2997-474: Is not an issue, as one of the engines is more than powerful enough to keep the aircraft aloft (see below). Mostly, ETOPS certification involves maintenance and design requirements ensuring that a failure of one engine cannot make the other one fail also. The engines and related systems need to be independent and (in essence) independently maintained. ETOPS/LROPS is often incorrectly thought to apply only to long overwater flights, but it applies to any flight more than

3108-414: Is often used in place of risk-sharing in the mistaken belief that you can transfer a risk to a third party through insurance or outsourcing. In practice, if the insurance company or contractor go bankrupt or end up in court, the original risk is likely to still revert to the first party. As such, in the terminology of practitioners and scholars alike, the purchase of an insurance contract is often described as

3219-830: Is the identification, evaluation, and prioritization of risks , followed by the minimization, monitoring, and control of the impact or probability of those risks occurring. Risks can come from various sources (i.e, threats ) including uncertainty in international markets , political instability , dangers of project failures (at any phase in design, development, production, or sustaining of life-cycles), legal liabilities , credit risk , accidents , natural causes and disasters , deliberate attack from an adversary, or events of uncertain or unpredictable root-cause . There are two types of events wiz. Risks and Opportunities. Negative events can be classified as risks while positive events are classified as opportunities. Risk management standards have been developed by various institutions, including

3330-483: Is therefore difficult or impossible to predict. A common error in risk assessment and management is to underestimate the wildness of risk, assuming risk to be mild when in fact it is wild, which must be avoided if risk assessment and management are to be valid and reliable, according to Mandelbrot. According to the standard ISO 31000 , "Risk management – Guidelines", the process of risk management consists of several steps as follows: This involves: After establishing

3441-518: The 777X in November 2013, while then-CEO Fabrice Brégier preferred to focus on product improvement rather than all-new concepts for 10 years. It would have a 10-abreast economy like the 777; its 565 m (6,081 sq ft) wing, slightly more than the 747-8, would have an 80 m (262 ft) span, as wide as the A380 , for a 892,900 lb (405 t) MTOW compared to 775,000 lb (352 t) for

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3552-584: The BAC One-Eleven , Fokker F28 , and Sud Aviation Caravelle , and larger ones with the original Boeing 737 . The original DC-9 was followed by the second generation in 1980, the MD-80 series, a lengthened DC-9-50 with a larger wing and a higher MTOW. This was further developed into the third generation, the MD-90 , in the early 1990s, as the body was stretched again, fitted with V2500 high-bypass turbofans, and an updated flight deck. The shorter and final version,

3663-399: The Boeing 777 , Boeing 787 and Airbus A350 have matched or surpassed older quad-jet designs such as the Boeing 747 and Airbus A340 in these aspects, and twinjets have been more successful in terms of sales than quad-jets. In 2012, Airbus studied a 470-seat twinjet competitor for the Boeing 747-8 with lower operating costs expected between 2023 and 2030, revived after Boeing launched

3774-490: The FAA for skydiving operations as of 2006. This is the last and only -21 series still airworthy, and after being out of service for over a decade, it returned to the sky on May 7th, 2024 During the mid 1990s, Northwest Airlines was the largest operator of the type in the world, flying 180 DC-9s. After its acquisition of Northwest Airlines, Delta Air Lines operated a sizable fleet of DC-9s, most of which were over 30 years old at

3885-521: The Federal Aviation Administration , and the US Air Force . The Series 20 has an overall length of 104.4 feet (31.82 m), a fuselage length of 92.1 feet (28.07 m), a passenger-cabin length of 60 feet (18.29 m), and a wingspan of 93.3 feet (28.44 m). The DC-9 Series 20 is powered by the 15,000 lbf (67 kN) thrust JT8D-11 engine. The Series 20 was originally certificated at an MTOW of 94,500 lb (42,900 kg) but this

3996-458: The Pratt & Whitney JT8D low-bypass turbofan engine, which had already been developed for the Boeing 727 , enabled Douglas to benefit from the preexisting investment. Pratt & Whitney had long collaborated with Douglas on various projects, thus their engine was a natural choice for the company. In order to reduce the considerable financial burden of its development, Douglas implemented one of

4107-695: The Project Management Institute , the National Institute of Standards and Technology , actuarial societies, and International Organization for Standardization . Methods, definitions and goals vary widely according to whether the risk management method is in the context of project management , security , engineering , industrial processes , financial portfolios , actuarial assessments , or public health and safety . Certain risk management standards have been criticized for having no measurable improvement on risk, whereas

4218-1048: The 1990s. The first PMBoK Project Management Body of Knowledge draft of 1987 doesn't mention opportunities at all. Modern project management school recognize the importance of opportunities. Opportunities have been included in project management literature since the 1990s, e.g. in PMBoK, and became a significant part of project risk management in the years 2000s, when articles titled "opportunity management" also begin to appear in library searches. Opportunity management thus became an important part of risk management. Modern risk management theory deals with any type of external events, positive and negative. Positive risks are called opportunities . Similarly to risks, opportunities have specific mitigation strategies: exploit, share, enhance, ignore. In practice, risks are considered "usually negative". Risk-related research and practice focus significantly more on threats than on opportunities. This can lead to negative phenomena such as target fixation . For

4329-753: The 777-200LR variant has the world's second longest aircraft range (behind Airbus A350-900 ULR). Other Boeing twinjets include the 767 , 757 (With the latter having stopped production, but still in commercial service) and 787 . Competitor Airbus produces the A320 family , the A330 , and the A350 . Some modern commercial airplanes still use four engines ( quad-jets ) like the Airbus A380 and Boeing 747-8 , which are classified as very large aircraft (over 400 seats in mixed-class configurations). Four engines are still used on

4440-432: The 777X, with a composite structure for an operating empty weight of 467,400 lb (212 t), and a 8,150 nmi (15,090 km) range at Mach 0.85. When flying far from diversionary airports (so called ETOPS/LROPS flights), the aircraft must be able to reach an alternate on the remaining engine within a specified time in case of one engine failure. When aircraft are certified according to ETOPS standards, thrust

4551-556: The DC-9 family aircraft has been involved in 276 major aviation accidents and incidents , including 156 hull-losses , with 3,697 fatalities combined (all generations of family members)= (1st gen., DC-9 series): 107 hull-losses & 2,250 fatalities + (2nd gen., MD-80 series): 46 hull-losses & 1,446 fatalities + (3rd gen., MD-90 series including Boeing 717 ): 3 hull-losses & 1 fatality. Related development Aircraft of comparable role, configuration, and era Related lists Twinjet A twinjet or twin-engine jet

McDonnell Douglas DC-9 - Misplaced Pages Continue

4662-414: The DC-9 was largely analogue, with flight controls mainly consisting of various levers, wheels, and knobs. The problem of deep stalling , revealed by the loss of the BAC One-Eleven prototype in 1963, was overcome through various changes, including the introduction of vortilons , small surfaces beneath the wings' leading edges used to control airflow and increase low-speed lift. The need for such features

4773-402: The DC-9, known as Model 2086. The first envisioned version seated 63 passengers and had a gross weight of 69,000 lb (31,300 kg). This design was changed into what would be the initial DC-9 variant. During February 1963, detailed design work commenced. On April 8, 1963, Douglas announced that it would proceed with the DC-9. Shortly thereafter, Delta Air Lines placed the initial order for

4884-487: The DC-9, ordering 15 aircraft along with options for another 15. By January 1965, Douglas had garnered orders for 58 DC-9 as well as options for a further 44. Unlike the competing but larger Boeing 727 trijet , which used as many 707 components as possible, the DC-9 was developed as an all-new design. Throughout its development, Douglas had placed considerable emphasis on making the airliner as economic as possible, as well as to facilitate its future growth. The adoption of

4995-517: The DC-9-10 can seat up to a maximum certified exit limit of 109 passengers. Typical all-economy layout is 90 passengers, and 72 passengers in a more typical mixed-class layout with 12 first and 60 economy-class passengers. All versions of the DC-9 are equipped with a tricycle undercarriage, featuring a twin nose unit and twin main units. The Series 20 was designed to satisfy a Scandinavian Airlines request for improved short-field performance by using

5106-521: The MD-90 was retired without freighter conversion. During the late 1950s, Douglas Aircraft studied a short- to medium-range airliner to complement their then-sole jetliner , the high-capacity, long-range DC-8 ( DC stands for Douglas Commercial ). The Model 2067 , a four-engined aircraft sized for medium-range routes was studied in depth, but work on it was abandoned after the proposal did not receive enough interest from airlines. In 1960, Douglas signed

5217-479: The MD-95, was renamed the Boeing 717 after McDonnell Douglas's merger with Boeing in 1997; it is powered by Rolls-Royce BR715 engines. The DC-9 family was produced between 1965 and 2006 with a total delivery of 2441 units: 976 DC-9s, 1191 MD-80s, 116 MD-90s, and 155 Boeing 717s. As of August 2022, 250 aircraft remain in service: 31 DC-9s (freighter), 116 MD-80s (mainly freighter), and 103 Boeing 717s (passenger), while

5328-468: The Model -51. Some visual cues to distinguish this version from other DC-9 variants include side strakes or fins below the side cockpit windows, spray deflectors on the nose gear, and thrust reversers angled inward 17 degrees as compared to the original configuration. The thrust reverser modification was developed by Air Canada for its earlier aircraft, and adopted by McDonnell Douglas as a standard feature on

5439-399: The Series 14 and 15, although, of the first four aircraft, three were built as Series 11s and one as Series 12. These were later converted to Series 14 standard. No Series 13 was produced. A passenger/cargo version of the aircraft, with a 136-by-81-inch (3.5 by 2.1 m) side cargo door forward of the wing and a reinforced cabin floor, was certificated on March 1, 1967. Cargo versions included

5550-405: The Series 15MC (minimum change) with folding seats that can be carried in the rear of the aircraft, and the Series 15RC (rapid change) with seats removable on pallets. These differences disappeared over the years as new interiors were installed. The Series 10 was unique in the DC-9 family in not having leading-edge slats. The Series 10 was designed to have short takeoff and landing distances without

5661-489: The Series 30, 40 and 50, has a slightly lower basic fuel capacity than the Series 10 (3,679 US gallons). The Series 30 was produced to counter Boeing's 737 twinjet; 662 were built, about 60% of the total. The -30 entered service with Eastern Airlines in February 1967 with a 14 ft 9 in (4.50 m) fuselage stretch, wingspan increased by just over 3 ft (0.9 m) and full-span leading edge slats , improving takeoff and landing performance. Maximum takeoff weight

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5772-585: The Series 31 is the JT8D-7 (14,000 lbf (62 kN) thrust), although it was also available with the -9 and -17 engines. On the Series 32 the JT8D-9 (14,500 lbf (64 kN) thrust) was standard, with the -11 also offered. The Series 33 was offered with the JT8D-9 or -11 (15,000 lbf (67 kN) thrust) engines and the heavyweight -34 with the JT8D-9, -15 (15,000 lbf (67 kN) thrust) or -17 (16,000 lbf (71 kN) thrust) engines. The DC-9-40

5883-483: The acceptance technique, the business intentionally assumes risks without financial protections in the hopes that possible gains will exceed prospective losses. The transfer approach shields the business from losses by shifting risks to a third party, frequently in exchange for a fee, while the third-party benefits from the project. By choosing not to participate in high-risk ventures, the avoidance strategy avoids losses but also loses out on possibilities. Last but not least,

5994-468: The aircraft were made during flight testing, such as the replacement of the original leading-edge slat design to achieve lower drag . The flight test program proceeded at a rapid pace; the initial Series 10 received airworthiness certification from the Federal Aviation Administration on November 23, 1965, permitting it to enter service with Delta Air Lines on December 8. Through the DC-9, Douglas had beaten rival company Boeing and their 737 to enter

6105-502: The appropriate level of management. For instance, a risk concerning the image of the organization should have top management decision behind it whereas IT management would have the authority to decide on computer virus risks. The risk management plan should propose applicable and effective security controls for managing the risks. For example, an observed high risk of computer viruses could be mitigated by acquiring and implementing antivirus software. A good risk management plan should contain

6216-474: The areas surrounding the improved traffic capacity. Over time, traffic thereby increases to fill available capacity. Turnpikes thereby need to be expanded in a seemingly endless cycles. There are many other engineering examples where expanded capacity (to do any function) is soon filled by increased demand. Since expansion comes at a cost, the resulting growth could become unsustainable without forecasting and management. The fundamental difficulty in risk assessment

6327-457: The case of an unlikely event, the probability of occurrence of which is unknown. Therefore, in the assessment process it is critical to make the best educated decisions in order to properly prioritize the implementation of the risk management plan . Even a short-term positive improvement can have long-term negative impacts. Take the "turnpike" example. A highway is widened to allow more traffic. More traffic capacity leads to greater development in

6438-504: The confidence in estimates and decisions seems to increase. Strategies to manage threats (uncertainties with negative consequences) typically include avoiding the threat, reducing the negative effect or probability of the threat, transferring all or part of the threat to another party, and even retaining some or all of the potential or actual consequences of a particular threat. The opposite of these strategies can be used to respond to opportunities (uncertain future states with benefits). As

6549-429: The consequences occurring during use of the product, or detection of the root causes of unwanted failures that the team can then avoid. Controls may focus on management or decision-making processes. All these may help to make better decisions concerning risk. Briefly defined as "sharing with another party the burden of loss or the benefit of gain, from a risk, and the measures to reduce a risk." The term 'risk transfer'

6660-451: The context, the next step in the process of managing risk is to identify potential risks. Risks are about events that, when triggered, cause problems or benefits. Hence, risk identification can start with the source of problems and those of competitors (benefit), or with the problem's consequences. Some examples of risk sources are: stakeholders of a project, employees of a company or the weather over an airport. When either source or problem

6771-460: The customers of the enterprise, as well as external impacts on society, markets, or the environment. There are various defined frameworks here, where every probable risk can have a pre-formulated plan to deal with its possible consequences (to ensure contingency if the risk becomes a liability ). Managers thus analyze and monitor both the internal and external environment facing the enterprise, addressing business risk generally, and any impact on

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6882-435: The decisions about how each of the identified risks should be handled. Mitigation of risks often means selection of security controls , which should be documented in a Statement of Applicability, which identifies which particular control objectives and controls from the standard have been selected, and why. Implementation follows all of the planned methods for mitigating the effect of the risks. Purchase insurance policies for

6993-434: The development of templates for identifying source, problem or event. Common risk identification methods are: Once risks have been identified, they must then be assessed as to their potential severity of impact (generally a negative impact, such as damage or loss) and to the probability of occurrence. These quantities can be either simple to measure, in the case of the value of a lost building, or impossible to know for sure in

7104-433: The fact that they only delivered software in the final phase of development; any problems encountered in earlier phases meant costly rework and often jeopardized the whole project. By developing in iterations, software projects can limit effort wasted to a single iteration. Outsourcing could be an example of risk sharing strategy if the outsourcer can demonstrate higher capability at managing or reducing risks. For example,

7215-402: The family members would be: First generation (Series 10, Series 20, Series 30, Series 40, and Series 50), second generation (Series 81, Series 82, Series 83, Series 87, and Series 88), and third generation (Series 90 and Series 95). The Series 10 (DC-9-10) was the smallest family member and the Series 90 (MD-90) was the largest. The original DC-9 series was followed in 1980 by the introduction of

7326-565: The findings of risk assessments in financial, market, or schedule terms. Robert Courtney Jr. (IBM, 1970) proposed a formula for presenting risks in financial terms. The Courtney formula was accepted as the official risk analysis method for the US governmental agencies. The formula proposes calculation of ALE (annualized loss expectancy) and compares the expected loss value to the security control implementation costs ( cost–benefit analysis ). Planning for risk management uses four essential techniques. Under

7437-440: The first shared-risk production arrangements for the DC-9, arranging for de Havilland Canada to produce the wing at its own financial cost in return for promises on prospective future production orders. The pace of development on the program was rapid. The first DC-9, a production model, flew on February 25, 1965. The second DC-9 flew a few weeks later, with a test fleet of five aircraft flying by July. Several key refinements to

7548-519: The high customer demand for the DC-9 made the company attractive for either an acquisition or a merger; Douglas would merge with the American aerospace company McDonnell Aircraft to form McDonnell Douglas in 1967. The DC-9 family is one of the longest-lasting aircraft in production and operation. It was produced on the final assembly line in Long Beach, California , beginning in 1965, and later

7659-416: The impact of the event equals risk magnitude." Risk mitigation measures are usually formulated according to one or more of the following major risk options, which are: Later research has shown that the financial benefits of risk management are less dependent on the formula used but are more dependent on the frequency and how risk assessment is performed. In business it is imperative to be able to present

7770-530: The introduction of ETOPS rules that allowed twin-engine jets to fly long-distance routes that were previously off-limits to them, Airbus was able to further develop the A300 as a medium- to long-range airliner to increased sales; Boeing launched its widebody twinjet, the Boeing 767 , in response. In the 1980s the Boeing 727 was discontinued, as its central engine bay would require a prohibitively expensive redesign to accommodate quieter high-bypass turbofans, and it

7881-449: The largest cargo aircraft capable of transporting outsize cargo , including strategic airlifters . Twin-jets tend to be more fuel-efficient than trijet (three engine) and quad-jet (four engine) aircraft. As fuel efficiency in airliners is a high priority, many airlines have been increasingly retiring trijet and quad-jet designs in favor of twinjets in the twenty-first century. The trijet designs were phased out first, in particular due to

7992-450: The loss attributed to war is retained by the insured. Also any amounts of potential loss (risk) over the amount insured is retained risk. This may also be acceptable if the chance of a very large loss is small or if the cost to insure for greater coverage amounts is so great that it would hinder the goals of the organization too much. Select appropriate controls or countermeasures to mitigate each risk. Risk mitigation needs to be approved by

8103-410: The more complicated design and maintenance issues of the middle engine mounted on the stabilizer. Early twinjets were not permitted by ETOPS restrictions to fly long-haul trans-oceanic routes, as it was thought that they were unsafe in the event of failure of one engine, so quad-jets were used. Quad-jets also had higher carrying capacity than comparable earlier twinjets. However, later twinjets such as

8214-429: The more-powerful engines and improved wings of the -30 combined with the shorter fuselage used in the -10. Ten Series 20 aircraft were produced, all as the Model -21. The -21 had slats and stairs at the rear of plane. In 1969, a DC-9 Series 20 at Long Beach was fitted with an Elliott Flight Automation Head-up display by McDonnell Douglas and used for successful three-month-long trials with pilots from various airlines,

8325-597: The most part, these methods consist of the following elements, performed, more or less, in the following order: The Risk management knowledge area, as defined by the Project Management Body of Knowledge PMBoK, consists of the following processes: The International Organization for Standardization (ISO) identifies the following principles for risk management: Benoit Mandelbrot distinguished between "mild" and "wild" risk and argued that risk assessment and management must be fundamentally different for

8436-405: The onset of its development, the DC-9 had been intended to be available in multiple versions to suit varying customer requirements; the first stretched version, the Series 30, with a longer fuselage and extended wing tips, flew on August 1, 1966, entering service with Eastern Air Lines in 1967. The initial Series 10 was followed by the improved -20 , -30 , and -40 variants. The final DC-9 series

8547-806: The organization or person making the risk management decisions. Another source, from the US Department of Defense (see link), Defense Acquisition University , calls these categories ACAT, for Avoid, Control, Accept, or Transfer. This use of the ACAT acronym is reminiscent of another ACAT (for Acquisition Category) used in US Defense industry procurements, in which Risk Management figures prominently in decision making and planning. Similarly to risks, opportunities have specific mitigation strategies: exploit, share, enhance, ignore. This includes not performing an activity that could present risk. Refusing to purchase

8658-584: The original DC-9 series. The MD-80 series includes the MD-81, MD-82, MD-83, MD-88, and shortest variant, the MD-87. The MD-80 series was further developed into the third generation, the MD-90 series, in the early 1990s. It has yet another fuselage stretch, an electronic flight instrument system (first introduced on the MD-88), and completely new International Aero V2500 high-bypass turbofan engines . In comparison to

8769-454: The original or first generation DC-9 series used the new designation with McDonnell Douglas initials (MD- prefix) followed by the year of development. The first derivative or second generation was the MD-80 series and the second derivative or third generation was the MD-90 series . Together, they formed the DC-9 family of 12 aircraft members (variants), and if the DC-9- designation were retained,

8880-400: The person who has been in the accident. The insurance policy simply provides that if an accident (the event) occurs involving the policyholder then some compensation may be payable to the policyholder that is commensurate with the suffering/damage. Methods of managing risk fall into multiple categories. Risk-retention pools are technically retaining the risk for the group, but spreading it over

8991-540: The possibility of replacing engines on the DC-9 with the JT8D-109 turbofan, a quieter and more efficient variant of the JT8D. This progressed to the flight-test stage, and tests achieved noise reduction between 8 and 9 decibels depending on the phase of flight. No further aircraft were modified, and the test aircraft was re-equipped with standard JT8D-9s prior to delivery to its airline customer. Two further developments of

9102-508: The primary sources of information. Nevertheless, risk assessment should produce such information for senior executives of the organization that the primary risks are easy to understand and that the risk management decisions may be prioritized within overall company goals. Thus, there have been several theories and attempts to quantify risks. Numerous different risk formulae exist, but perhaps the most widely accepted formula for risk quantification is: "Rate (or probability) of occurrence multiplied by

9213-458: The reduction approach lowers risks by implementing strategies like insurance, which provides protection for a variety of asset classes and guarantees reimbursement in the event of losses. Once risks have been identified and assessed, all techniques to manage the risk fall into one or more of these four major categories: Ideal use of these risk control strategies may not be possible. Some of them may involve trade-offs that are not acceptable to

9324-666: The requirement that an aircraft be able to continue a takeoff if an engine fails after the takeoff decision speed is reached. Thus, with all engines operating, trijets must be able to produce at least 150% of the minimum thrust required to climb and quad-jets 133%. Conversely, since a twinjet will lose half of its total thrust if an engine fails, they are required to produce 200% of the minimum thrust required to climb when both engines are operating. Because of this, twinjets typically have higher thrust-to-weight ratios than aircraft with more engines, and are thus able to accelerate and climb faster. Risk management Risk management

9435-413: The risks being faced. Risk analysis results and management plans should be updated periodically. There are two primary reasons for this: Enterprise risk management (ERM) defines risk as those possible events or circumstances that can have negative influences on the enterprise in question, where the impact can be on the very existence, the resources (human and capital), the products and services, or

9546-406: The risks that it has been decided to transferred to an insurer, avoid all risks that can be avoided without sacrificing the entity's goals, reduce others, and retain the rest. Initial risk management plans will never be perfect. Practice, experience, and actual loss results will necessitate changes in the plan and contribute information to allow possible different decisions to be made in dealing with

9657-525: The second generation of the DC-9 family, the MD-80 series. This was originally called the DC-9-80 (short Series 80 and later stylized Super 80). It was a lengthened DC-9-50 with a higher maximum takeoff weight (MTOW), a larger wing , new main landing gear , and higher fuel capacity. The MD-80 series features a number of variants of the JT8D turbofan engine that had higher thrust ratings than those available on

9768-426: The second variant, Series 20, has one version (Series 21); the third variant, Series 30, has four versions (Series 31, Series 32, Series 33 and Series 34); the fourth variant, Series 40, has one version (Series 41); and the fifth or final variant, Series 50, has one version (Series 51). The original DC-9 (later designated the Series 10) was the smallest DC-9 variant. The -10 was 104.4 ft (31.8 m) long and had

9879-421: The series 50. It was also applied to many earlier DC-9s in the course of regular maintenance. As of May 2024, a total of 30 DC-9 series aircraft remain in service, of which 20 are operated by Aeronaves TSM and two passenger aircraft in service with African Express Airways , and the rest in cargo service. With the existing DC-9 fleet shrinking, modifications do not appear to be likely to occur, especially since

9990-447: The severity of the loss or the likelihood of the loss from occurring. For example, sprinklers are designed to put out a fire to reduce the risk of loss by fire. This method may cause a greater loss by water damage and therefore may not be suitable. Halon fire suppression systems may mitigate that risk, but the cost may be prohibitive as a strategy . Acknowledging that risks can be positive or negative, optimizing risks means finding

10101-442: The short-haul jet market, a key factor that contributed to the DC-9 becoming the best selling airliner in the world for a time. By May 1976, the company had delivered 726 aircraft of the DC-9 family, which was more than double the number of its nearest competitor. However, following decades of intense competition between the two airliners, the DC-9 would eventually be overtaken as the world's best selling airliner by Boeing's 737. From

10212-435: The structure associated with the slat is a more efficient torque box than the structure associated with the slotted Krueger. The wing had a six-percent increase in chord, all ahead of the front spar, allowing the 15 percent chord slat to be incorporated. The Series 30 was built in four main sub-variants. The DC-9-30 was offered with a selection of variants of JT8D including the -1, -7, -9, -11, -15. and -17. The most common on

10323-400: The tail-mounted engines was the reduction in foreign object damage from ingested debris from runways and aprons, but with this position, the engines could ingest ice streaming off the wing roots. The third was the absence of engines in underslung pods, which permitted a reduction in fuselage ground clearance, making the airliner more accessible to baggage handlers and passengers. The cockpit of

10434-694: The third configuration both engines are within the fuselage, side-by-side, used by most fighters since the 1960s. Later fighters using this configuration include the Su-27 'Flanker', the F-15 Eagle , and the F-22 Raptor . The first twinjet to fly was the German fighter prototype Heinkel He 280 , flying in April 1941 with a pair of nacelled Heinkel HeS 8 axial-flow turbojets. The twinjet configuration

10545-494: The time. With severe increases in fuel prices in the summer of 2008, Northwest Airlines began retiring its DC-9s, switching to Airbus A319s that are 27% more fuel efficient. As the Northwest/Delta merger progressed, Delta returned several stored DC-9s to service. Delta Air Lines made its last DC-9 commercial flight from Minneapolis/St. Paul to Atlanta on January 6, 2014, with the flight number DL2014. As of June 2022,

10656-426: The two types of risk. Mild risk follows normal or near-normal probability distributions , is subject to regression to the mean and the law of large numbers , and is therefore relatively predictable. Wild risk follows fat-tailed distributions , e.g., Pareto or power-law distributions , is subject to regression to the tail (infinite mean or variance, rendering the law of large numbers invalid or ineffective), and

10767-448: The use of leading-edge high-lift devices. Therefore, the wing design of the Series 10 featured airfoils with extremely high maximum-lift capability to obtain the low stalling speeds necessary for short-field performance. The Series 10 has an overall length of 104.4 feet (31.82 m), a fuselage length of 92.1 feet (28.07 m), a passenger-cabin length of 60 feet (18.29 m), and a wingspan of 89.4 feet (27.25 m). The Series 10

10878-502: The very successful MD-80, relatively few MD-90s were built. The shorter and final variant, the MD-95, was renamed the Boeing 717 after McDonnell Douglas's merger with Boeing in 1997 and before aircraft deliveries began. The fuselage length and wing are very similar to those of the DC-9-30, but much use was made of lighter, modern materials. Power is supplied by two BMW/Rolls-Royce BR715 high-bypass turbofan engines. China's Comac ARJ21

10989-450: The way. On large passenger jets, the cost of the engines makes up a significant proportion of the plane's final cost. Each engine also requires separate service, paperwork, and certificates. Having two larger engines as opposed to three or four smaller engines will typically significantly reduce both the purchase and maintenance costs of a plane. Regulations governing the required thrust levels for transport aircraft are typically based upon

11100-416: The whole group involves transfer among individual members of the group. This is different from traditional insurance, in that no premium is exchanged between members of the group upfront, but instead, losses are assessed to all members of the group. Risk retention involves accepting the loss, or benefit of gain, from a risk when the incident occurs. True self-insurance falls in this category. Risk retention

11211-567: The wing design makes retrofitting difficult. DC-9s are therefore likely to be further replaced in service by newer airliners such as Boeing 737 , Airbus A320 , Embraer E-Jets , and the Airbus A220 . However one former Scandinavian Airlines DC-9-21 is operated as a skydiving jump platform at Perris Valley Airport in Perris, California . With the steps on the ventral stairs removed, it is the only airline transport class jet certified to date by

11322-415: Was increased to 98,000 lb (44,000 kg), eight percent more than on the higher weight Series 14s and 15s. The aircraft's MLW is 95,300 lb (43,200 kg) and MZFW is 84,000 lb (38,000 kg). Typical range with maximum payload is 1,000 nmi (1,900 km; 1,200 mi), increasing to 1,450 nmi (2,690 km; 1,670 mi) with maximum fuel. The Series 20, using the same wing as

11433-439: Was limited to 80,000 lb (36,300 kg) for a two-person flight crew by the then-Federal Aviation Agency regulations at the time. The commercial passenger aircraft have five abreast layout for economy seating that can accommodate 80 to 135 passengers, depending on version and seating arrangement. Turnarounds were simplified by built-in airstairs, including one in the tail, which shortened boarding and deplaning times. The DC-9

11544-500: Was offered with the 14,000 lbf (62 kN)-thrust JT8D-1 and JT8D-7. All versions of the DC-9 are equipped with an AlliedSignal (Garrett) GTCP85 APU, located in the aft fuselage. The Series 10, as with all later versions of the DC-9, is equipped with a two-crew analog flightdeck. The Series 14 was originally certificated with an MTOW of 85,700 lb (38,900 kg), but subsequent options offered increases to 86,300 and 90,700 lb (41,100 kg). The aircraft's MLW in all cases

11655-975: Was on a common line with the second generation of the DC-9 family, the MD-80 , with which it shares its line number sequence. Following the delivery of 976 DC-9s and 108 MD-80s, McDonnell Douglas stopped series production of the DC-9 in December 1982. The last member of the DC-9 family, the Boeing 717, was produced until 2006. The DC-9 family was produced in total 2441 units: 976 DC-9s (first generation), 1191 MD-80s (second generation), 116 MD-90s, and 155 Boeing 717s (third generation). This compared to 2,970 Airbus A320s and 5,270 Boeing 737s delivered as of 2006. Studies aimed at further improving DC-9 fuel efficiency , by means of retrofitted wingtips of various types, were undertaken by McDonnell Douglas, but these did not demonstrate significant benefits, especially with existing fleets shrinking. The wing design makes retrofitting difficult. Between 1973 and 1975, McDonnell Douglas studied

11766-599: Was originally designed to perform a maximum of 40,000 landings. The DC-9 has two rear-mounted JT8D turbofan engines, relatively small, efficient wings, and a T-tail . The tail-mounted engine design facilitated a clean wing without engine pods, which had numerous advantages. First, the flaps could be longer, unimpeded by pods on the leading edge and engine-blast concerns on the trailing edge. This simplified design improved airflow at low speeds and enabled lower takeoff and approach speeds, thus lowering field length requirements and keeping wing structure light. The second advantage of

11877-656: Was soon supplanted by twinjets for the narrow-body market; Airbus with the A320 , and Boeing with the 757 and updated "classic" variants of the 737 . During that decade only McDonnell Douglas continued development of the trijet design with an update to the DC-10 , the MD-11 , which initially had a range advantage over its closest medium wide-body competitors which were twinjets, the in-production Boeing 767 and Airbus A300/A310. In contrast to McDonnell Douglas sticking with their existing trijet configuration, Airbus (which never produced

11988-416: Was the -50 , which first flew in 1974. The DC-9 series, the first generation of the DC-9 family, would become a long term commercial success for the manufacturer. However, early production of the type had come at a higher unit cost than had been anticipated, leading to DC-9s being sold at a loss. The unfavorable early economics of the type negatively impacted Douglas, pushing it into fiscal hardship. However,

12099-434: Was the largest version of the DC-9 to enter airline service. It features an 8 ft 2 in (2.49 m) fuselage stretch and seats up to 139 passengers. It entered revenue service in August 1975 with Eastern Airlines and included a number of detail improvements, a new cabin interior, and more powerful JT8D-15 or -17 engines in the 16,000 and 16,500 lbf (71 and 73 kN) class. McDonnell Douglas delivered 96, all as

12210-544: Was typically 110,000 lb (50,000 kg). Engines for Models -31, -32, -33, and -34 included the P&;W JT8D-7 and JT8D-9 rated at 14,500 lbf (64 kN) of thrust, or JT8D-11 with 15,000 lbf (67 kN). Unlike the Series 10, the Series 30 had leading-edge devices to reduce the landing speeds at higher landing weights; full-span slats reduced approach speeds by six knots despite 5,000 lb greater weight. The slats were lighter than slotted Krueger flaps , since

12321-484: Was used for short-range narrow-bodied aircraft such as the McDonnell Douglas DC-9 and Boeing 737 . The Airbus A300 was initially not successful when first produced as a short-range widebody, as airlines operating the A300 on short-haul routes had to reduce frequencies to try and fill the high-capacity aircraft, and lost passengers to airlines operating more frequent narrow-body flights. However, after

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