title: Galactic Republic

text: The story of the Galactic Republic's rise, fall and resurrection have been compared to those of the real-world Roman Republic and Weimar Germany. The story of its "fall and redemption" has also been compared to that of Anakin Skywalker.


title: Galactic Republic

text: Brake and Chase (2016) compared the hypothesised colonisation of the Core Worlds by Coruscanti humans to the state of the space colonisation by humans from the Earth, which had taken its first step with NASA's Apollo program of 1961–1972, just before George Lucas invented "Star Wars". They argued that Lucas offered a solution to the Fermi paradox: indeed, most of the "Star Wars" galaxy was conquered/colonised and submitted to the central government of the Republic rather quickly by the expansionist humans from the Core Worlds soon after they acquired the necessary rocket technology for interstellar travel, but there are still large unchartered Unknown Regions which are simply too far from the fashionable Core Worlds to have been fully explored (as exploration of the Unknown Regions is lethally dangerous), let alone colonised. Thus, it's possible that the Solar System is also situated "in the Milky Way's version of the Unknown Regions", and that even if there are other species in the Milky Way, which may even have established a "Star Wars"-like Galactic Republic or Empire, the Earth and its human civilisation have so far been in unchartered and dangerous hyperspace-travel territory (from that galactic civilisation's point of view), and humans themselves are still too technologically limited to make contact with it.


title: Galactic Republic

text: Silvio (2007) posits that "Star Wars" films should be understood as being heavily influenced by the time in which they were created. The prequel trilogy where the Galactic Republic was first depicted was influenced by the presidency of George W. Bush, including the war on terror, the Iraq War, and the increased U.S. security apparatus with the Patriot Act. Anakin Skywalker's line "If you're not with me, then you're my enemy" is an echo of Bush's war on terror dichotomy that "Either you are with us, or you are with the terrorists." George Lucas even confirmed that Padmé Amidala's line "So this is how liberty dies... to thunderous applause" invokes the Bush administration's passing of the Patriot Act and Wars in Iraq and Afghanistan without public scrutiny.


title: COVID-19 testing

text: COVID-19 testing involves analyzing samples to assess the current or past presence of SARS-CoV-2. The two main types of tests detect either the presence of the virus or antibodies produced in response to infection. Molecular tests for viral presence through its molecular components are used to diagnose individual cases and to allow public health authorities to trace and contain outbreaks. Antibody tests (serology immunoassays) instead show whether someone once had the disease. They are less useful for diagnosing current infections because antibodies may not develop for weeks after infection. It is used to assess disease prevalence, which aids the estimation of the infection fatality rate.


title: COVID-19 testing

text: Individual jurisdictions have adopted varied testing protocols, including whom to test, how often to test, analysis protocols, sample collection and the uses of test results. This variation has likely significantly impacted reported statistics, including case and test numbers, case fatality rates and case demographics. Because SARS-CoV-2 transmission occurs days after exposure (and before onset of symptoms), there is an urgent need for frequent surveillance and rapid availability of results.


title: COVID-19 testing

text: Test analysis is often performed in automated, high-throughput, medical laboratories by medical laboratory scientists. Rapid self-tests and point-of-care testing are also available and can offer a faster and less expensive method to test for the virus although with a lower accuracy.


title: COVID-19 testing

text: Positive viral tests indicate a current infection, while positive antibody tests indicate a prior infection. Other techniques include a CT scan, checking for elevated body temperature, checking for low blood oxygen level, and detection by trained dogs.


title: COVID-19 testing

text: Detection of the virus is usually done either by looking for the virus's inner RNA, or pieces of protein on the outside of the virus. Tests that look for the viral antigens (parts of the virus) are called "antigen tests".


title: COVID-19 testing

text: There are multiple types of tests that look for the virus by detecting the presence of the virus's RNA. These are called "nucleic acid" or "molecular" tests, after molecular biology. , the most common form of molecular test is the reverse transcription polymerase chain reaction (RT-PCR) test. Other methods used in molecular tests include CRISPR, isothermal nucleic acid amplification, digital polymerase chain reaction, microarray analysis, and next-generation sequencing.


title: COVID-19 testing

text: Polymerase chain reaction (PCR) is a process that amplifies (replicates) a small, well-defined segment of DNA many hundreds of thousands of times, creating enough of it for analysis. Test samples are treated with certain chemicals that allow DNA to be extracted. Reverse transcription converts RNA into DNA.


title: COVID-19 testing

text: Reverse transcription polymerase chain reaction (RT-PCR) first uses reverse transcription to obtain DNA, followed by PCR to amplify that DNA, creating enough to be analyzed. RT-PCR can thereby detect SARS-CoV-2, which contains only RNA. The RT-PCR process generally requires a few hours. These tests are also referred to as molecular or genetic assays.


title: COVID-19 testing

text: Real-time PCR (qPCR) provides advantages including automation, higher-throughput and more reliable instrumentation. It has become the preferred method.


title: COVID-19 testing

text: The combined technique has been described as real-time RT-PCR or quantitative RT-PCR and is sometimes abbreviated qRT-PCR, rRT-PCR or RT-qPCR, although sometimes RT-PCR or PCR are used. The Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) guidelines propose the term "RT-qPCR", but not all authors adhere to this.


title: COVID-19 testing

text: Average sensitivity for rapid molecular tests depend on the brand. For ID NOW, the average sensitivity was 73.0% with an average specificity of 99.7%; for Xpert Xpress the average sensitivity was 100% with an average specificity of 97.2%.


title: COVID-19 testing

text: In a diagnostic test, sensitivity is a measure of how well a test can identify true positives and specificity is a measure of how well a test can identify true negatives. For all testing, both diagnostic and screening, there is usually a trade-off between sensitivity and specificity, such that higher sensitivities will mean lower specificities and vice versa. A 90% specific test will correctly identify 90% of those who are uninfected, leaving 10% with a false positive result.


title: COVID-19 testing

text: Samples can be obtained by various methods, including a nasopharyngeal swab, sputum (coughed up material), throat swabs, deep airway material collected via suction catheter or saliva. Drosten et al. remarked that for 2003 SARS, "from a diagnostic point of view, it is important to note that nasal and throat swabs seem less suitable for diagnosis, since these materials contain considerably less viral RNA than sputum, and the virus may escape detection if only these materials are tested."


title: COVID-19 testing

text: Sensitivity of clinical samples by RT-PCR is 63% for nasal swab, 32% for pharyngeal swab, 48% for feces, 72–75% for sputum, and 93–95% for bronchoalveolar lavage.


title: COVID-19 testing

text: The likelihood of detecting the virus depends on collection method and how much time has passed since infection. According to Drosten tests performed with throat swabs are reliable only in the first week. Thereafter the virus may abandon the throat and multiply in the lungs. In the second week, sputum or deep airways collection is preferred.


title: COVID-19 testing

text: Collecting saliva may be as effective as nasal and throat swabs, although this is not certain. Sampling saliva may reduce the risk for health care professionals by eliminating close physical interaction. It is also more comfortable for the patient. Quarantined people can collect their own samples. A saliva test's diagnostic value depends on sample site (deep throat, oral cavity, or salivary glands). Some studies have found that saliva yielded greater sensitivity and consistency when compared with swab samples.


title: COVID-19 testing

text: On 15 August 2020, the US FDA granted an emergency use authorization for a saliva test developed at Yale University that gives results in hours.


title: COVID-19 testing

text: On 4 January 2021, the US FDA issued an alert about the risk of false results, particularly false negative results, with the Curative SARS-Cov-2 Assay real-time RT-PCR test.


title: COVID-19 testing

text: Viral burden measured in upper respiratory specimens declines after symptom onset. Following recovery, many patients no longer have detectable viral RNA in upper respiratory specimens. Among those who do, RNA concentrations three days following recovery are generally below the range in which replication-competent virus has been reliably isolated. No clear correlation has been described between length of illness and duration of post-recovery shedding of viral RNA in upper respiratory specimens.


title: COVID-19 testing

text: Isothermal nucleic acid amplification tests also amplify the virus's genome. They are faster than PCR because they don't involve repeated heating and cooling cycles. These tests typically detect DNA using fluorescent tags, which are read out with specialized machines.


title: COVID-19 testing

text: CRISPR gene editing technology was modified to perform the detection: if the CRISPR enzyme attaches to the sequence, it colors a paper strip. The researchers expect the resulting test to be cheap and easy to use in point-of-care settings. The test amplifies RNA directly, without the RNA-to-DNA conversion step of RT-PCR.


title: COVID-19 testing

text: An antigen is the part of a pathogen that elicits an immune response. Antigen tests look for antigen proteins from the viral surface. In the case of a coronavirus, these are usually proteins from the surface spikes. SARS-CoV-2 antigens can be detected before onset of COVID-19 symptoms (as soon as SARS-CoV-2 virus particles) with more rapid test results, but with less sensitivity than PCR tests for the virus.


title: COVID-19 testing

text: COVID-19 rapid antigen tests are lateral flow immunoassays that detect the presence of a specific viral antigen, which indicates current viral infection. Antigen tests produce results quickly (within approximately 15–30 minutes), and most can be used at the point-of-care or as self-tests. Self-tests are rapid tests that can be taken at home or anywhere, are easy to use, and produce rapid results. Antigen tests can be performed on nasopharyngeal, nasal swab, or saliva specimens.


title: COVID-19 testing

text: Antigen tests that can identify SARS-CoV-2 offer a faster and less expensive method to test for the virus. Antigen tests are generally less sensitive than real-time reverse transcription polymerase chain reaction (RT-PCR) and other nucleic acid amplification tests (NAATs).


title: COVID-19 testing

text: Antigen tests may be one way to scale up testing to much greater levels. Isothermal nucleic acid amplification tests can process only one sample at a time per machine. RT-PCR tests are accurate but require too much time, energy and trained personnel to run the tests. "There will never be the ability on a [PCR] test to do 300 million tests a day or to test everybody before they go to work or to school," Deborah Birx, head of the White House Coronavirus Task Force, said on 17 April 2020. "But there might be with the antigen test."


title: COVID-19 testing

text: Samples may be collected via nasopharyngeal swab, a swab of the anterior nares, or from saliva (obtained by various methods including "lollipop tests" for children). The sample is then exposed to paper strips containing artificial antibodies designed to bind to coronavirus antigens. Antigens bind to the strips and give a visual readout. The process takes less than 30 minutes, can deliver results at point of care, and does not require expensive equipment or extensive training.


title: COVID-19 testing

text: Swabs of respiratory viruses often lack enough antigen material to be detectable. This is especially true for asymptomatic patients who have little if any nasal discharge. Viral proteins are not amplified in an antigen test. A Cochrane review based on 64 studies investigating the efficacy of 16 different antigen tests determined that they correctly identified COVID-19 infection in an average of 72% of people with symptoms, compared to 58% of people without symptoms. Tests were most accurate (78%) when used in the first week after symptoms first developed, likely because people have the most virus in their system in the first days after they are infected. While some scientists doubt whether an antigen test can be useful against COVID-19, others have argued that antigen tests are highly sensitive when viral load is high and people are contagious, making them suitable for public health screening. Routine antigen tests can quickly identify when asymptomatic people are contagious, while follow-up PCR can be used if confirmatory diagnosis is needed.


title: COVID-19 testing

text: The body responds to a viral infection by producing antibodies that help neutralize the virus. Blood tests (also called serology tests or serology immunoassays) can detect the presence of such antibodies. Antibody tests can be used to assess what fraction of a population has once been infected, which can then be used to calculate the disease's mortality rate. They can also be used to determine how much antibody is contained in a unit of convalescent plasma, for COVID-19 treatment, or to verify if a given vaccine generates an adequate immune response.


title: COVID-19 testing

text: SARS-CoV-2 antibodies' potency and protective period have not been established. Therefore, a positive antibody test may not imply immunity to a future infection. Further, whether mild or asymptomatic infections produce sufficient antibodies for a test to detect has not been established. Antibodies for some diseases persist in the bloodstream for many years, while others fade away.


title: COVID-19 testing

text: The most notable antibodies are IgM and IgG. IgM antibodies are generally detectable several days after initial infection, although levels over the course of infection and beyond are not well characterized. IgG antibodies generally become detectable 10–14 days after infection and normally peak around 28 days after infection. This pattern of antibody development seen with other infections, often does not apply to SARS-CoV-2, however, with IgM sometimes occurring after IgG, together with IgG or not occurring at all. Generally, however, median IgM detection occurs 5 days after symptom onset, whereas IgG is detected a median 14 days after symptom onset. IgG levels significantly decline after two or three months.


title: COVID-19 testing

text: Genetic tests verify infection earlier than antibody tests. Only 30% of those with a positive genetic test produced a positive antibody test on day 7 of their infection.


title: COVID-19 testing

text: RDTs typically use a small, portable, positive/negative lateral flow assay that can be executed at point of care. RDTs may process blood samples, saliva samples, or nasal swab fluids. RDTs produce colored lines to indicate positive or negative results.


title: COVID-19 testing

text: ELISAs can be qualitative or quantitative and generally require a lab. These tests usually use whole blood, plasma, or serum samples. A plate is coated with a viral protein, such as a SARS-CoV-2 spike protein. Samples are incubated with the protein, allowing any antibodies to bind to it. The antibody-protein complex can then be detected with another wash of antibodies that produce a color/fluorescent readout.


title: COVID-19 testing

text: Neutralization assays assess whether sample antibodies prevent viral infection in test cells. These tests sample blood, plasma or serum. The test cultures cells that allow viral reproduction (e.g., Vero E6 cells). By varying antibody concentrations, researchers can visualize and quantify how many test antibodies block virus replication.


title: COVID-19 testing

text: Chemiluminescent immunoassays are quantitative lab tests. They sample blood, plasma, or serum. Samples are mixed with a known viral protein, buffer reagents and specific, enzyme-labeled antibodies. The result is luminescent. A chemiluminescent microparticle immunoassay uses magnetic, protein-coated microparticles. Antibodies react to the viral protein, forming a complex. Secondary enzyme-labeled antibodies are added and bind to these complexes. The resulting chemical reaction produces light. The radiance is used to calculate the number of antibodies. This test can identify multiple types of antibodies, including IgG, IgM, and IgA.


title: COVID-19 testing

text: Most if not all large scale COVID-19 antibody testing looks for binding antibodies only and does not measure the more important neutralizing antibodies (NAb). A NAb is an antibody that neutralizes the infectivity of a virus particle by blocking its attachment to or entry into a susceptible cell; enveloped viruses, like e.g. SARS-CoV-2, are neutralized by the blocking of steps in the replicative cycle up to and including membrane fusion. A non-neutralizing antibody either does not bind to the crucial structures on the virus surface or binds but leaves the virus particle infectious; the antibody may still contribute to the destruction of virus particles or infected cells by the immune system. It may even enhance infectivity by interacting with receptors on macrophages. Since most COVID-19 antibody tests return a positive result if they find only binding antibodies, these tests cannot indicate that the subject has generated protective NAbs that protect against re-infection.


title: COVID-19 testing

text: It is expected that binding antibodies imply the presence of NAbs and for many viral diseases total antibody responses correlate somewhat with NAb responses but this is not established for COVID-19. A study of 175 recovered patients in China who experienced mild symptoms reported that 10 individuals had no detectable NAbs at discharge, or thereafter. How these patients recovered without the help of NAbs and whether they were at risk of re-infection was not addressed. An additional source of uncertainty is that even if NAbs are present, viruses such as HIV can evade NAb responses.


title: COVID-19 testing

text: Studies have indicated that NAbs to the original SARS virus (the predecessor to the current SARS-CoV-2) can remain active for two years and are gone after six years. Nevertheless, memory cells including Memory B cells and Memory T cells can last much longer and may have the ability to reduce reinfection severity.


title: COVID-19 testing

text: Sudden loss of smell can be used to screen people on a daily basis for COVID-19. A study by the National Institutes of Health showed that those infected with SARS-CoV-2 could not smell a 25% mixture of ethanol and water. Because various conditions can lead to the loss of the sense of smell, a sniff test would not be definitive but indicate the need for a PCR test. Because the loss of the sense of smell shows up before other symptoms, there has been a call for widespread sniff testing. Health care bureaucracies have generally ignored sniff tests even though they are quick, easy and capable of being self-administered daily. This has led some medical journals to write editorials supporting the adoption of sniff testing.


title: COVID-19 testing

text: Typical visible features on CT initially include bilateral multilobar ground-glass opacities with a peripheral or posterior distribution. COVID-19 can be identified with higher precision using CT than with RT-PCR.


title: COVID-19 testing

text: Subpleural dominance, crazy paving, and consolidation may develop as the disease evolves. Chest CT scans and chest x-rays are not recommended for diagnosing COVID-19. Radiologic findings in COVID-19 lack specificity.


title: COVID-19 testing

text: Chest X-rays, computed tomography scans and ultrasounds are all ways the coronavirus disease can be detected.


title: COVID-19 testing

text: A chest x-ray is a portable lightweight machine. This machine is typically more available than polymerase chain reaction and computerized tomography scans. it only takes approximately 15 seconds per patient. This makes chest-x ray readily accessible and inexpensive. It also has quick turnaround time and can be crucial to the clinical equipment in the detection of coronavirus disease.


title: COVID-19 testing

text: Computerized tomography scans involve looking at 3D images from various angles. This is not as available as chest-x ray, but still only takes about 15 minutes per patient. Computerized tomography has been a known routine scanning for pneumonia diagnosis, therefore can also be used to diagnose coronavirus disease. Computerized tomography scans may help with ongoing illness monitoring throughout treatment. Patients who had low-grade symptoms and high body temperatures revealed significant lung indications on their chest computed tomography scans. They emphasized how important chest computerized tomography scans are for determining how serious the coronavirus disease infection is.


title: COVID-19 testing

text: Ultrasound can be another tool to detect coronavirus disease. An ultrasound is a type of imaging exam that produces images using sound waves. Unlike computerized tomography scans and x-rays, ultrasound does not use radiation. Moreover, it is inexpensive, simple to use, repeatable, and has several additional advantages. Using a hand-held mobile machine, ultrasound examinations can be performed in a variety of healthcare settings.


title: COVID-19 testing

text: There are some downsides to using imaging, however. The equipment needed for computed tomography scans is not available in most hospitals, making it not as effective as some other tools used for detection of the coronavirus disease. One of the difficult tasks in a pandemic is manually inspecting each report, which takes numerous radiology professionals and time. There were several problems with early studies of using chest computerized tomography scans for diagnosing coronavirus. Some of these problems included the disease severity characters being different in severe and hospitalized cases. The criteria for doing a chest computerized tomography scan were not defined. There was also no characterization of positive chest computerized tomography scans results. The computerized tomography scans findings were not the same as positive computerized tomography scans findings of coronavirus. In a typical clinical setting, chest imaging is not advised for routine screening of COVID-19. Patients with asymptomatic to mild symptoms are not recommended to be tested via chest computerized tomography scans. However, it is still crucial to use, particularly when determining complications or disease progression. Chest imaging also is not always the first route to take with patients who have high risk factors for COVID. High risk patients that had mild symptoms, chest imaging findings were limited. Although a computerized tomography scan is a strong tool in the diagnosis of COVID-19, it is insufficient to identify COVID-19 alone due to the poor specificity and the difficulties that radiologists may experience in distinguishing COVID-19 from other viral pneumonia on chest computerized tomography scans.


title: COVID-19 testing

text: The standard blood test (quick scan) taken at the emergency room measures different values. By use of the blood quick scan the CoLab score is calculated with a developed algorithm based on how the coronavirus causes changes in the blood. The software is intended for use in emergency rooms to quickly rule out the presence of the disease in incoming patients. A not negative result is followed by a PCR (polymerase chain reaction) or LAMP (loop-mediated isothermal amplification) test.


title: COVID-19 testing

text: The breath test by a Coronavirus breathalyzer is a pre-screening test for people who have no or mild symptoms of COVID-19. A not negative result is followed by a PCR or LAMP test.


title: COVID-19 testing

text: In May 2021, Reuters reported that Dutch researchers at Wageningen University had shown that trained bees could detect the virus in infected samples in seconds and this could benefit countries where test facilities are in short supply. A two-month study by the Necker-Cochin hospital Paris in conjunction with the French national veterinary school reported in May 2021 that dogs were more reliable than current lateral flow tests.


title: COVID-19 testing

text: Researchers in Paris in March 2022 reported in a preprint not yet peer-reviewed that trained dogs were very effective for rapidly detecting the presence of SARS-Cov2 in people, whether displaying symptoms or not. The dogs were presented with sweat samples to smell from 335 people, of whom 78 with symptoms and 31 without tested positive by PCR. The dogs detected 97% of the symptomatic and 100% of the asymptomatic infections. They were 91% accurate at identifying volunteers who were not infected, and 94% accurate at ruling out the infection in people without symptoms. The authors said "Canine testing is non-invasive and provides immediate and reliable results.Further studies will be focused on direct sniffing by dogs to evaluate sniffer dogs for mass pre-test in airports, harbors, railways stations, cultural activities or sporting events."


title: COVID-19 testing

text: Tollotest is a molecular test that detects the activity of a SARS-CoV2 protease, which is a biomarker for active infection.


title: COVID-19 testing

text: In January 2020, scientists from China published the first genetic sequences of SARS-CoV-2 via the GISAID initiative, a program that had handled mostly genetic sequence data from animal-borne influenzas. Researchers around the world used that data to build molecular tests for the virus. Antigen- and antibody-based tests were developed later.


title: COVID-19 testing

text: Even once the first tests were created, the supply was limited. As a result, no countries had reliable data on the prevalence of the virus early in the pandemic. The WHO and other experts called for ramping up testing as the best way to slow the spread of the virus. Shortages of reagent and other testing supplies became a bottleneck for mass testing in the EU, the UK and the US. Early tests also encountered problems with reliability.


title: COVID-19 testing

text: In drive-through testing, the person undergoing testing remains in a vehicle while a healthcare professional approaches the vehicle and obtains a sample, all while taking appropriate precautions such as wearing personal protective equipment (PPE). Drive-through centers helped South Korea accelerate its testing program.


title: COVID-19 testing

text: In Hong Kong test subjects can stay home and receive a specimen tube. They spit into it, return it and later get the result.


title: COVID-19 testing

text: Pooled testing can improve turnaround time, by combining a number of samples to be tested together. If the pool result is negative, all samples are negative. If the test result is positive, samples will need to be individually tested.


title: COVID-19 testing

text: In Israel, researchers at Technion and Rambam Hospital developed a method for testing samples from 64 patients simultaneously, by pooling the samples and only testing further if the combined sample was positive. Pool testing was then adopted in Israel, Germany, Ghana South Korea, Nebraska, China and the Indian states of Uttar Pradesh, West Bengal, Punjab, Chhattisgarh and Maharashtra.


title: COVID-19 testing

text: Open source, multiplexed designs released by Origami Assays can test as many as 1122 patient samples using only 93 assays. These balanced designs can be run in small laboratories without robotic liquid handlers.


title: COVID-19 testing

text: One study proposed a rapid immune response assay as a screening test, with a confirmatory nucleic acid test for diagnosis, followed by a rapid antibody test to determine course of action and assess population exposure/herd immunity.


title: COVID-19 testing

text: Required testing levels are a function of disease spread. The more the cases, the more tests are needed to manage the outbreak. COVID-19 tends to grow exponentially at the beginning of an outbreak, meaning that the number of required tests initially also grows exponentially. If properly targeted testing grows more rapidly than cases, it can be contained.


title: COVID-19 testing

text: Economist Paul Romer reported that the US has the technical capacity to scale up to 20 million tests per day, which is his estimate of the scale needed to fully remobilize the economy. The Edmond J. Safra Center for Ethics estimated on 4 April 2020 that this capacity could be available by late July 2020. Romer pointed to single-molecule real-time sequencing equipment from Pacific Biosciences and to the Ion Torrent Next-Generation Sequencing equipment from ThermoFisher Scientific. According to Romer, "Recent research papers suggest that any one of these has the potential to scale up to millions of tests per day." This plan requires removing regulatory hurdles. Romer estimated that $100 billion would cover the costs.


title: COVID-19 testing

text: Romer also claimed that high test accuracy is not required if tests are administered frequently enough. He ran model simulations in which 7% of the population is tested every day using a test with a 20% false negative rate and a 1% false positive rate. The average person would be tested roughly every two weeks. Those who tested positive would go into quarantine. Romer's simulation indicated that the fraction of the population that is infected at any given time (known as the attack rate) peaks reaches roughly 8% in about thirty days before gradually declining, in most runs reaching zero at 500 days, with cumulative prevalence remaining below 20%.


title: COVID-19 testing

text: A study found that, despite possibly suboptimal implementation, the snapshot mass-testing approach conducted by Slovakia by which ~80% of its population was tested for COVID-19 within a weekend at the end of October 2020 was highly efficacious, decreasing observed prevalence by 58% within one week and by 70% compared to a hypothetical scenario of no snapshot mass-testing. The significant reduction resulted from a set of complementary lockdown and quarantine measures whereby citizens who tested positive were quarantined synchronously the weeks afterwards.


title: COVID-19 testing

text: As of August 2020, the WHO recognizes wastewater surveillance of SARS-CoV-2 as a potentially useful source of information on the prevalence and temporal trends of COVID-19 in communities, while highlighting that gaps in research such as viral shedding characteristics should be addressed. Such aggregative testing may have detected early cases. Studies show that wastewater-based epidemiology has the potential for an early warning system and monitoring for COVID-19 infections. This may prove particularly useful once large shares of regional populations are vaccinated or recovered and don't need to conduct rapid tests while in some cases being infectious nevertheless.


title: COVID-19 testing

text: Tests are available that look for viral DNA using either polymerase chain reaction (PCR) or loop-mediated isothermal amplification (LAMP) technology.


title: COVID-19 testing

text: Tests developed in China, France, Germany, Hong Kong, Japan, the United Kingdom, and the US targeted different parts of the viral genome. WHO adopted the German system for manufacturing kits sent to low-income countries without the resources to develop their own.


title: COVID-19 testing

text: PowerChek Coronavirus looks for the "E" gene shared by all beta coronaviruses, and the RdRp gene specific to SARS-CoV-2.


title: COVID-19 testing

text: Abbott Laboratories' ID Now nucleic acid test uses isothermal amplification technology. The assay amplifies a unique region of the virus's RdRp gene; the resulting copies are then detected with "fluorescently-labeled molecular beacons". The test kit uses the company's "toaster-size" ID Now device, which is widely deployed in the US. The device can be used in laboratories or in point of care settings, and provides results in 13 minutes or less.


title: COVID-19 testing

text: Primerdesign offers its Genesig Real-Time PCR test system. Roche Molecular Systems offers the Cobas 6800/8800 systems; they are offered among others by the United Nations.


title: COVID-19 testing

text: Quidel's "Sofia2 SARS Antigen FIA" is a lateral flow test that uses monoclonal antibodies to detect the virus's nucleocapsid (N) protein. The result is read out by the company's Sofia2 device using immunofluorescence. The test is simpler and cheaper but less accurate than nucleic acid tests. It can be deployed in laboratories or at point of care and gives results in 15 minutes. A false negative result occurs if the sample's antigen level is positive but below the test's detection limit, requiring confirmation with a nucleic acid test.


title: COVID-19 testing

text: The Innova SARS-CoV-2 Antigen Rapid Qualitative Test was never approved for use in the United States, but was being sold by the company anyway. The FDA inspected Innova facilities in California in March and April 2021, and found inadequate quality assurance of tests manufactured in China. On 23 April 2021, the company issued a recall. The FDA warned consumers to return or destroy the devices because the rate of false positives and false negatives found in clinical trials were higher than the rate claimed by the packaging. Over 1 billion tests from the company have been distributed in the UK, with £3 billion in funding as part of Operation Moonshot, and the MHRK has authorized exceptional use until at least 28 August 2021. Concerned experts pointed out that accuracy dropped significantly when screening was conducted by the public instead of by a medical professional, and that the test was not designed to screen asymptomatic people. A 2020 study found 79% of positive cases were found when used by laboratory scientists, but only 58% when used by the general public and 40% when used for city-wide screening in Liverpool.


title: COVID-19 testing

text: Antibodies are usually detectable 14 days after the onset of the infection. Multiple jurisdictions survey their populations using these tests. The test requires a blood sample.


title: COVID-19 testing

text: A summary review in BMJ has noted that while some "serological tests … might be cheaper and easier to implement at the point of care [than RT-PCR]", and such testing can identify previously infected individuals, "caution is warranted … using serological tests for … epidemiological surveillance". The review called for higher quality studies assessing accuracy with reference to a standard of "RT-PCR performed on at least two consecutive specimens, and, when feasible, includ[ing] viral cultures." CEBM researchers have called for in-hospital 'case definition' to record "CT lung findings and associated blood tests" and for the WHO to produce a "protocol to standardise the use and interpretation of PCR" with continuous re-calibration.


title: COVID-19 testing

text: Accuracy is measured in terms of specificity and selectivity. Test errors can be false positives (the test is positive, but the virus is not present) or false negatives, (the test is negative, but the virus is present).


title: COVID-19 testing

text: Sensitivity indicates whether the test accurately identifies whether the virus is present. Each test requires a minimum level of viral load in order to produce a positive result. A 90% sensitive test will correctly identify 90% of infections, missing the other 10% (a false negative). Even relatively high sensitivity rates can produce high rates of false negatives in populations with low incidence rates.


title: COVID-19 testing

text: In a diagnostic test, sensitivity is a measure of how well a test can identify true positives and specificity is a measure of how well a test can identify true negatives. For all testing, both diagnostic and screening, there is usually a trade-off between sensitivity and specificity, such that higher sensitivities will mean lower specificities and vice versa. A 90% specific test will correctly identify 90% of those who are uninfected, leaving 10% with a false positive result.


title: COVID-19 testing

text: Low-specificity tests have a low positive predictive value (PPV) when prevalence is low. For example, suppose incidence is 5%. Testing 100 people at random using a test that has a specificity of 95% would yield on average 5 people who are actually negative who would incorrectly test positive. Since 5% of the subjects actually are positive, another five would also test positive correctly, totaling 10 positive results. Thus, the PPV is 50%, an outcome no different from a coin toss. In this situation, assuming that the result of a second test is independent of the first test, retesting those with a first positive result increases the PPV to 94.5%, meaning that only 4.5% of the second tests would return the incorrect result, on average less than 1 incorrect result.


title: COVID-19 testing

text: The time course of infection affects the accuracy of some tests. Samples may be collected before the virus has had a chance to establish itself or after the body has begun to eliminate it. A May 2020 review of PCR-RT testing found that the median probability of a false-negative result decreased from 100% on day 1, to 67% on day 4. On the day of symptom onset, the probability was 38%, which decreased to 20% 3 days later.


title: COVID-19 testing

text: RT-PCR is the most commonly-used diagnostic test. PCR tests by nasopharyngeal swab have a sensitivity of 73%, but systematic analysis of specificity has not been determined due to the lack of PCR studies with a control group.


title: COVID-19 testing

text: In one study sensitivity was highest at week one (100%), followed by 89.3%, 66.1%, 32.1%, 5.4% and zero by week six since symptom onset.


title: COVID-19 testing

text: Sensitivity is also a function of the number of PCR cycles, as well as time and temperature between sample collection and analysis. A cycle threshold of 20 cycles would be adequate to detect SARS-Cov-2 in a highly infective person. Cycle thresholds above 34 are increasingly likely to give false positives outside of high biosafety level facilities.


title: COVID-19 testing

text: On July 16, 2020, Dr. Anthony Fauci of the US CDC indicated that positive results obtained from RT-PCR tests run at more than 35 cycles were almost always "just dead nucleotides". On August 29, 2020, the New York Times reported that, "In three sets of testing data that include cycle thresholds, compiled by officials in Massachusetts, New York and Nevada … most tests set the limit at 40 [cycles], a few at 37" and that the CDC was examining the use of cycle threshold measures "for policy decisions," On July 21, 2021, the CDC, in their "Real-Time RT-PCR Diagnostic Pan: Instructions for Use", indicated tests results should be determined at 40 cycles.


title: COVID-19 testing

text: A Dutch CDC-led laboratory investigation compared 7 PCR kits. Test kits made by BGI, R-Biopharm AG, BGI, KH Medical and Seegene showed high sensitivity.


title: COVID-19 testing

text: High sensitivity kits are recommended to assess people without symptoms, while lower sensitivity tests are adequate when diagnosing symptomatic patients.


title: COVID-19 testing

text: The University of Oxford's Centre for Evidence-Based Medicine (CEBM) has pointed to mounting evidence that "a good proportion of 'new' mild cases and people re-testing positives via RT-PCR after quarantine or discharge from hospital are not infectious, but are simply clearing harmless virus particles which their immune system has efficiently dealt with", and have called for "an international effort to standardize and periodically calibrate testing". On 7 September, the UK government issued "guidance for procedures to be implemented in laboratories to provide assurance of positive SARS-CoV-2 RNA results during periods of low prevalence, when there is a reduction in the predictive value of positive test results".


title: COVID-19 testing

text: On 4 January 2021, the US FDA issued an alert about the risk of false results, particularly false negative results, with the Curative SARS-Cov-2 Assay real-time RT-PCR test.


title: COVID-19 testing

text: One study reported that the ID Now COVID-19 test showed sensitivity of 85.2%. Abbott responded that the issue could have been caused by analysis delays. Another study rejected the test in their clinical setting because of this low sensitivity.


title: COVID-19 testing

text: The WHO recommends countries that do not have testing capacity and national laboratories with limited experience on COVID-19 send their first five positives and the first ten negative COVID-19 samples to one of the 16 WHO reference laboratories for confirmatory testing. Out of the sixteen reference laboratories, seven are in Asia, five in Europe, two in Africa, one in North America and one in Australia.


title: COVID-19 testing

text: Iceland managed the pandemic with aggressive contact tracing, inbound travel restrictions, testing, and quarantining, but with less aggressive lock-downs.


title: COVID-19 testing

text: Researchers tested the entire population of Vo', the site of Italy's first COVID-19 death. They tested about 3,400 people twice, at an interval of ten days. About half the people testing positive had no symptoms. All discovered cases were quarantined. Along with restricting travel to the commune, new infections were eliminated.


title: COVID-19 testing

text: Unlike other Asian countries, Japan did not experience a pandemic of SARS or MERS, so the country's PCR testing system was not well developed. Japan preferentially tested patients with severe illness and their close contacts at the beginning. Japan's Novel Coronavirus Expert Meeting chose cluster measures to identify infections clusters. The Expert Meeting analyzed the outbreak from Wuhan and identified conditions leading to clusters (closed spaces, crowded spaces and close-contact), and asked people to avoid them.


title: COVID-19 testing

text: In January, contact tracers took action shortly after the first infection was found. Only administrative tests were carried out at first, until insurance began covering PCR tests on 6 March. Private companies began to test, and the test system gradually expanded.


title: COVID-19 testing

text: On 3 April, those with positive tests were legally permitted to recuperate at home or in a hotel if they had asymptomatic or mild illness, ending the hospital bed shortage. The first wave (from China) was contained, but a second wave (caused by returnees from Europe and the US) in mid-March led to spreading infection in April. On 7 April, Japan declared a state of emergency, (less strict than a lockdown, because it did not block cities or restrict outings). On 13 May, antigen test kits became covered by insurance, and were combined with a PCR test for diagnosis.


title: COVID-19 testing

text: Japan's PCR test count per capita remained far smaller than in some other countries even though its positive test rate was lower. Excess mortality was observed in March. The Expert Meeting stated, "The Japanese health care system originally carries out pneumonia surveillance, allowing it to detect most of the severely ill patients who develop pneumonia. There are a large number of CT scanners in Japan and they have spread to small hospitals all over the country, so pneumonia patients are rarely missed. In that sense, it meets the same standards as other countries that mainly carry out PCR tests." The group recommended using CT scans data and doctor's findings for diagnosis. On the Diamond Princess cruise ship, many people who initially tested negative later tested positive. Half of coronavirus-positives there who remained mild or asymptomatic had pneumonia findings on CT scans and their CT image showed a frosted glass shadow that is characteristic of infection.


title: COVID-19 testing

text: As of 18 July, Japan's daily PCR testing capacity was about 32,000, more than three times the 10,000 cases as of April. When the antigen test is added to it, the number is about 58,000. The number of tests per 1,000 people in the United States is about 27 times that of Japan, the UK is 20 times, Italy is 8 times, and South Korea is twice (as of 26 July).


title: COVID-19 testing

text: The number of those infected with coronavirus and inpatients has increased in July, but the number of serious cases has not increased. This is thought to be due to the proper testing of those infected in July compared to those in April. In April, the number of tests could not catch up with the increase in the number of infected people, and the test standards were strict, so the test positive rate exceeded 30% at the peak. It means that there were quite a few cases where the those infected was not PCR tested. It is thought that the severe case was preferentially tested though there were a lot of mild cases and asymptomatic carriers mainly in the young during the first wave. In other words, it became possible to grasp the actual situation of infection much better than before by strengthening the testing system. At the end of July, accommodation facilities for mild and asymptomatic carriers became full, and the authorities requested hospitals to prepare beds for the mild. However, it became difficult to treat patients with other illnesses and to maintain the ICU system including the staff due to the occupation of hospital beds by patients with mild symptoms.


title: COVID-19 testing

text: On 27 April 2020, Russia tested 3 million people and had 183,000 positive results. On 28 April Anna Popova, head of Federal Service for Surveillance in Healthcare (Roszdravnadzor) stated that 506 laboratories were testing; that 45% of those who tested positive had no symptoms; that 5% of patients had a severe form; and 40% of infections were from family members. Illness improved from six days to one day after symptoms appeared. Antibody testing was carried out on 3,200 Moscow doctors, finding 20% immunity.


title: COVID-19 testing

text: With contact tracing, inbound travel restrictions, testing, and quarantining, Singapore arrested the initial spread without complete lockdown.


title: COVID-19 testing

text: In late October 2020 Slovakia tested 3.62 million people in a weekend, from a population of 5.4m, representing 67% of the total (or 82% of the adult population), 38,359 tested positive, representing 1.06% of those tested. The government considered the mass test would significantly assist in controlling the virus and avoid a lockdown and may repeat the exercise at a later date.


title: COVID-19 testing

text: South Korea's broad testing approach helped reduce spread. Testing capacity, largely in private sector labs, was built up over several years by the South Korean government in the early 2000s.


title: COVID-19 testing

text: The government exploited the resident registration number (RRN) system. Authorities mobilized young men who were eligible for military service as social service agents, security and public health doctors. Public health doctors were mainly dispatched to public health centers and life treatment centers where mildly ill patients were accommodated. They performed PCR tests and managed mild patients. Social service agents worked in pharmacies to fill staff shortages. Korea's 10k PCR tests per million residents was the world's highest as of 13 April rising to 20k by mid-June. Twenty-seven Korean companies exported test kits worth $48.6 million in March, and were asked to provide test kits or humanitarian assistance by more than 120 countries. Korean authorities set up a treatment center to isolate and manage patients with asymptomatic and minor illnesses in one facility in order to vacate hospital beds for the more severely ill.


title: COVID-19 testing

text: Centers were sited mainly at national facilities and corporate training centers. The failure of Korea's MERS quarantine in May 2015 left Korea more prepared for COVID-19 than countries that did not face that pandemic. Then President Park Geun-hye allowed Korean CDC-approved private sector testing for infectious diseases in 2016. Korea already had a system for isolating, testing and treating infectious disease patients separately from others. Patients with respiratory illness but no epidemiological relevance were treated at the National Hospital, and those with epidemiological relevance were treated at selected clinics.


title: COVID-19 testing

text: Korea established a large scale drive-through/walk-through" test testing program. However, the most common method was "mobile examination". In Daegu City, 54% of samples were collected by 23 March in home or hospital. Collecting samples door-to-door of avoided the risk of travel by possibly infected patients, but required additional staff. Korea solved the problem by drafting more than 2,700 public insurance doctors.


title: COVID-19 testing

text: The government disclosed personal information to the public via KCDC without patient consent. The authorities used digital surveillance to trace possible spread.


title: COVID-19 testing

text: In January 2021, the COVID-19 testing results of the UAE came under scrutiny, as Denmark suspended the Emirati flights for five days. The European nation said that it barred the flights from the UAE due to growing suspicion of irregularities in the testing process being followed in the Gulf nation. Denmark's Minister of Transport, Benny Engelbrecht said that they were taking time to ensure that the negative tests of travelers from the Emirates were a real screening carried out appropriately.


title: COVID-19 testing

text: New York State's control measures consisted of PCR tests, stay-at-home measures and strengthening the healthcare system. On 29 February before its first case, the state allowed testing at the Wordsworth Center. They managed to convince the CDC to approve tests at state laboratories and the FDA to approve a test kit. As of 13 March the state was conducting more than 1,000 daily tests, growing to 10,000/day on 19 March. In April, the number exceeded 20,000. Many people queued at hospitals to get tested. On 21 March New York City health officials directed medical providers to test only those entering the hospital, for lack of PPE.


title: COVID-19 testing

text: Following an outbreak, 94% of the 4,800 aircraft carrier crew were tested. Roughly 60 percent of the 600-plus sailors who tested positive were asymptomatic. Five infected sailors who completed quarantine subsequently developed flu-like symptoms and again tested positive.


title: COVID-19 testing

text: In 2020, Nevada received a donation of 250,000 Covid testing kits, which were a product of China's leading genetics company, BGI Group. A UAE-based firm owned by Tahnoun bin Zayed Al Nahyan, Group 42 partnered with the BGI Group to supply the testing kits to Nevada. However, the US Department of Homeland Security and the State Department raised a warning for Nevada hospitals to not use the Chinese-made testing kits, as there were concerns around the involvement of the Chinese government, test accuracy and privacy of the patients.


title: COVID-19 testing

text: A shortage of trained medical laboratory scientists, assay reagents, analyzers, transport medium, and PPE coupled with high demand had limited initially limited the availability of testing and led to significantly increased turnaround times.


title: COVID-19 testing

text: Testing strategies vary by country and over time, with some countries testing very widely, while others have at times focused narrowly on only testing the seriously ill. The country that tests only people showing symptoms will have a higher figure for "Confirmed"/"tested" than the country that also tests others. If two countries are alike in every respect, including which people they test, the one that tests more people will have a higher "Confirmed / population". Studies have also found that countries that test more, relative to the number of deaths, have lower estimated case fatality rates and younger age distributions of cases.


"James while John had had had had had had had had had had had a better effect on the teacher" is an English sentence used to demonstrate lexical ambiguity and the necessity of punctuation,


title: James while John had had had had had had had had had had had a better effect on the teacher

text: In human information processing research, the sentence has been used to show how readers depend on punctuation to give sentences meaning, especially in the context of scanning across lines of text. The sentence is sometimes presented as a puzzle, where the solver must add the punctuation.


text: The sentence refers to two students, James and John, who are required by an English teacher to describe a man who had suffered from a cold in the past. John writes "The man had a cold", which the teacher marks incorrect, while James writes the correct "The man had had a cold". James's answer, being more grammatical, resulted in a better impression on the teacher.


text: In each of the five "had had" word pairs in the above sentence, the first of the pair is in the past perfect form. The italicized instances denote emphasis of intonation, focusing on the differences in the students' answers, then finally identifying the correct one.


text: Alternatively, the sentence can also be read as John's answer being better than James', simply by placing the same punctuation in a different arrangement through the sentence:


text: The sentence can be given as a grammatical puzzle or an item on a test, for which one must find the proper punctuation to give it meaning. Hans Reichenbach used a similar sentence ("John where Jack had...") in his 1947 book "Elements of Symbolic Logic" as an exercise for the reader, to illustrate the different levels of language, namely object language and metalanguage. The intention was for the reader to add the needed punctuation for the sentence to make grammatical sense.


text: In research showing how people make sense of information in their environment, this sentence was used to demonstrate how seemingly arbitrary decisions can drastically change the meaning, analogous to how changes in the punctuation and quotes in the sentence show that the teacher alternately prefers James's work and John's work (e.g., compare: 'James, while John had had "had", had...' vs. 'James, while John had had "had had", ...').


text: The sentence is also used to show the semantic vagueness of the word "had", as well as to demonstrate the difference between using a word and mentioning a word.


text: It has also been used as an example of the complexities of language, its interpretation, and its effects on a person's perceptions.


text: For the syntactic structure to be clear to a reader, this sentence requires, at a minimum, that the two phrases be separated by using a semicolon, period, en-dash or em-dash. Still, Jasper Fforde's novel "The Well of Lost Plots" employs a variation of the phrase to illustrate the confusion that may arise even from well-punctuated writing:


title: Learjet

text: Learjet is a Canadian-owned aerospace manufacturer of business jets for civilian and military use based in Wichita, Kansas, United States. Founded in the late 1950s by William Powell Lear as Swiss American Aviation Corporation, it has been a subsidiary of Canadian Bombardier Aerospace since 1990, which markets it as the "Bombardier Learjet Family". The 3,000th Learjet was delivered in June 2017.


title: Learjet

text: In February 2021, Bombardier announced the end of production for all new Learjet aircraft in 2021, with the continuation of support and maintenance for aircraft currently in service.


title: Learjet

text: Learjet was one of the first companies to manufacture a private, luxury aircraft. Lear's preliminary design was based upon an experimental American military aircraft known as the Marvel, substituting fuselage-mounted turbojet engines for ducted fan turboshaft engines. However, that preliminary design was abandoned and the final Learjet design was instead adapted from an abortive 1950s Swiss ground-attack fighter aircraft, the FFA P-16.


title: Learjet

text: The basic structure of the Swiss P-16 aircraft was seen by Bill Lear and his team as a good starting point to the development of a business jet, and formed the Swiss American Aircraft Corporation, located in Altenrhein, Switzerland, and staffed with design engineers from Switzerland, Germany and Britain. The aircraft was originally intended to be called the SAAC-23. The wing with its distinctive tip fuel tanks and landing gear of the first Learjets were little changed from those used by the fighter prototypes. Although building the first jet started in Switzerland, the tooling for building the aircraft was moved to Wichita, Kansas, in 1962. Bill Jr stated that it took too long to get anything done in Switzerland despite the cheaper labor costs. LearJet was in a temporary office which opened in September 1962 while the plant at Wichita's airport was under construction. On February 7, 1963, assembly of the first Learjet began. The next year, the company was renamed the Lear Jet Corporation.


title: Learjet

text: The original Learjet 23 was a six- to eight-seater and first flew on October 7, 1963, with the first production model being delivered in October 1964. Just over a month later, Lear Jet became a publicly owned corporation. Several derived models followed, with the Model 24 first flying on February 24, 1966, and the Model 25 first flying on August 12, 1966. On September 19 of the same year, the company was renamed Lear Jet Industries Inc.


title: Learjet

text: On April 10, 1967, Bill Lear's approximately 60% share of the venture was acquired by the Gates Rubber Company of Denver, Colorado, for US$ 27,000,000. Lear remained on the company board until April 2, 1969, when the company was merged with Gates Aviation Corporation and was renamed Gates Learjet Corporation. In 1971, the first Model 25 powered by a Garrett TFE731-2 turbofan engine was flown. This aircraft later became the successful Learjet 35. That year, the company was awarded the President's "E" Award for promoting export sales.


title: Learjet

text: In 1974, the worldwide Learjet fleet had exceeded the one-million flight hours mark and, in 1975, the company produced its 500th jet, both industry firsts. By late 1976, the company increased monthly aircraft production to ten.


title: Learjet

text: On August 24, 1977, the Learjet 28 made its first flight. It was based on the Learjet 25, but received a completely new wing fitted with winglets. These resulted in both improved performance and fuel economy and inspired the name "Longhorn" for the short-lived Learjet 28/29 and for some of the more successful models that followed.


title: Learjet

text: On April 19, 1979, the prototype for the Model 54/55/56 series made its first flight, and on July 7, 1983, a standard production Model 55 set six new time-to-climb records for its weight class.


title: Learjet

text: In 1984, Gates Learjet announced the start of their Aerospace Division, a high technology endeavor. However, by the end of the year the company had ceased production of its commercial jets in an effort to reduce inventories. This lasted until February 1986, when the company headquarters were transferred to Tucson, Arizona, and production was restarted both in Wichita and Tucson.


title: Learjet

text: On September 10, 1985, the Aerospace Division was awarded a contract to produce parts for the Space Shuttle's main engines. In 1987, Gates Learjet was acquired by Integrated Acquisition and the next year the name was changed to Learjet Corporation. By January 1989, all production had been moved from the Tucson facility back to Wichita with an employment of 1,250.


title: Learjet

text: In 1990, Canadian company Bombardier Aerospace purchased the Learjet Corporation. The aircraft were then marketed as the "Bombardier Learjet Family". On October 10, 1990, the Learjet 60 mid-sized aircraft had its first flight, followed on October 7, 1995, by the Learjet 45.


title: Learjet

text: In October 2007, Bombardier Learjet launched a brand new aircraft program, the Learjet 85. It was the first FAR Part-25 all-composite business aircraft.


title: Learjet

text: Bombardier celebrated the 45th anniversary of the first flight by a Learjet with 2008's "Year of Learjet campaign". One of its highlights was British Formula One racing driver Lewis Hamilton racing a Learjet and winning an event at the Farnborough Air Show.


title: Learjet

text: On February 11, 2021, Bombardier announced the end production of all Learjet aircraft. Bombardier also announced they would continue to fully support the Learjet fleet well into the future, and launched the Learjet RACER re-manufacturing program for the Learjet 40 and Learjet 45 aircraft.


title: Learjet

text: As Bombardier focuses on its larger Challenger and Global jets, the final aircraft, a Learjet 75, was delivered on 28 March 2022 after 60 years of production, delivering more than 3,000 aircraft, of which more than 2,000 remain in service.


title: Learjet

text: Learjet started off in Wichita, Kansas, and as of 2013 has over 3,200 employees. Wichita was not the only candidate for the location of Lear's project. Grand Rapids, Michigan, and Ohio were also both locations that were being considered. There were already a few other aircraft companies that were located in Kansas, which meant there were many more potential workers who would possess the skills that Lear needed to run his company in the design and manufacturing of the aircraft. Lear was offered an industrial revenue bond of 1.2 million US dollars. This would be known as the first historical industrial revenue bond offered by the city. To this day, the Learjet facility is still located in Wichita, Kansas, and is currently getting ready to be renovated, by expanding the Flight Test Center and building a new center for delivery.


title: CDU/CSU

text: CDU/CSU, unofficially the Union parties (, ) or the Union, is a centre-right Christian-democratic political alliance of two political parties in Germany: the Christian Democratic Union of Germany (CDU) and the Christian Social Union in Bavaria (CSU).


title: CDU/CSU

text: The CSU contests elections only in Bavaria, while the CDU operates in the other 15 states of Germany. The CSU also reflects the particular concerns of the largely rural, Catholic south. While the two Christian Democratic parties are commonly described as sister parties, they have been sharing a common parliamentary group, the CDU/CSU Parliamentary Group, in the German Bundestag () since the foundation of the Federal Republic of Germany in 1949. According to German Federal Electoral Law, members of a parliamentary group which share the same basic political aims must not compete with one another in any federal state.


title: CDU/CSU

text: The parties themselves officially remain completely independent with their own leadership and only few issue- or age-based joint organisations, which makes the alliance informal. However, in practice the committees of the parties harmonise their decisions with each other and the two parties run behind a common candidate for Chancellor, and the leader of one party is usually invited to party conventions of the other party.


title: CDU/CSU

text: Both the CDU and CSU are members of the European People's Party and the International Democrat Union. Both parties sit in the European People's Party group in the European Parliament. The CDU and CSU share a common youth organisation, the Youth Union, a common pupil organisation, the , a common student organisation, the Association of Christian Democratic Students and a common "Mittelstand" organisation, the .


title: CDU/CSU

text: Both the CDU and the CSU were established after World War II and share a perspective based on Christian democracy and conservatism and hold the dominant centre-right position in the German political spectrum. The CSU is usually considered the de facto successor of the Weimar Republic–era Bavarian People's Party (BVP), which itself broke away from the all-German Catholic Centre Party (DZP) after World War I, but the CSU included also parts of the agrarian and liberal Bavarian Peasants' League and parts of the bavarian wing of the DVP. However the CDU's foundation was the result of a major re-organisation of the centre-right political camp compared to the Weimar Republic. Although the CDU was largely built as the "de facto" successor of the Centre Party, it successfully opened out to non-Catholic Christians (many of them affiliated with the German People's Party until 1933) and successfully asserted itself as the only major conservative party (outside of Bavaria) against initial competition from other Catholic, Protestant or national conservative parties such as the German Party during the early years of the Federal Republic.


title: CDU/CSU

text: The BVP became the sister party of the DZP and they did not compete against each other except for the May 1924 German federal election, the 1924 Bavarian state election and the 1925 German presidential election. The DZP and BVP were mostly jointly represented at the Imperial governments. Similarly to the modern CDU/CSU split, the Bavarian People's Party was generally seen as the party further to the political right, as evidenced by the 1925 second round of the presidential election when the Center Party backed Rhenish Catholic and Weimar Coalition candidate Wilhelm Marx while the BVP made common cause with the monarchist and nationalist parties in backing Prussian junker and former general Paul von Hindenburg despite him being a Protestant and the long-standing mutual animosity between Bavaria and Prussia.


title: CDU/CSU

text: Alliance for Germany was a coalition for the 1990 East German general election consisting of the CDU, the DSU and Democratic Awakening which merged into the CDU.


title: CDU/CSU

text: During the 1970s and then again after 2015, several CSU leaders have expressed the wish to make the CSU a truly independent party without formal ties to the CDU. Usually they combined this wish with an expansion to the rest of Germany.


title: CDU/CSU

text: After 1969, CDU and CSU were in the opposition in the Bundestag. CDU leader Kohl wanted to win the liberal FDP again for a coalition with the CDU/CSU, while the CSU leader Strauß had different plans. He aimed for a right wing majority without the FDP. Additionally, Strauß thought little of the current CDU leader Kohl, a more moderate Christian Democrat.


title: CDU/CSU

text: Strauß believed that CDU and CSU should be separate national parties to address different audience: the CDU the moderate, social and liberal voters, the CSU the conservative voters. After the elections they should still form a government together.


title: CDU/CSU

text: In 1975, the federal CDU declared Kohl to be the next CDU/CSU chancellor candidate for the 1976 general elections - without consulting the CSU. Kohl did well in the elections on October 3, 1976, although Social Democrats and FDP had still enough seats to continue their coalition. Kohl decided to leave his post as prime minister of the state of Rhineland-Palatinate for the chairmanship of the CDU/CSU Bundestag faction.


title: CDU/CSU

text: In November that year, the 49 CSU Bundestag members gathered in the party's educational centre in Wildbad Kreuth, Southern Bavaria. 30 of them voted for a proposal to form a CSU Bundestag parliamentary group of its own. CDU leader Kohl was informed only later via the media. This 'Kreuth separation decision' "(Kreuther Trennungsbeschluss)" was a major political earthquake and caused the CDU to react swiftly and resolutely. Kohl threatened the CSU by preparing the creation of a CDU party organization in Bavaria. In March 1977, the "CDU Bayern" was supposed to be founded in Nuremberg.


title: CDU/CSU

text: During the conflict, the Aktionsgemeinschaft Vierte Partei, the Bund Freies Deutschland (West-Berlin), the Christlich Soziale Wähler Union (Saarland), the Deutsche Union (North Rhine-Westphalia) and the Partei Freier Bürger (Bremen) were founded. On 12 December 1976, the vote was rescinded after the CDU had threatened in turn to form local associations within Bavaria and to run in Bavarian elections against the CSU.


title: CDU/CSU

text: Strauß himself polemicised against Kohl in a closed CSU meeting on November 24 (this "Wienerwald speech" was leaked, and published on November 29 in "Der Spiegel"):


title: CDU/CSU

text: It turned out that most local CSU leaders and also conservative CDU state leaders did not approve a separation between CSU and CDU. The CSU Bundestag members revoked their decision. On December 7, the CDU/CSU Bundestag group elected Kohl as its chairman. In 1980, Strauß was the joint CDU/CSU chancellor candidate and lost more than 4 percent of the votes. This ended his ambitions for a federal CSU.


title: CDU/CSU

text: Under the chairmanship of Angela Merkel (2000-2018), the CDU left some right wing positions behind and shifted more to the political centre. Especially the 2015 refugee crisis divided the German population and caused conflict between the more liberal CDU and the more anti migrant party CSU.


title: CDU/CSU

text: Therefore, a federal CSU was discussed again among party members and journalists. For example conservative "Welt" columnist Ansgar Graw wrote in 2016 that CDU and CSU lost its stance as a law and order party. As Merkel's CDU could not move to the right without losing credibility, Graw called the CSU to become a federal party, a right wing party that rigorously deports asylum seekers without right to stay. On the contrary, former CSU leader Theo Waigel warned against a separate election campaign. In such a campaign, CDU and CSU would fight much more each other than the rest of the parties.


title: CDU/CSU

text: In 2018, Interior Minister Horst Seehofer, a former Minister-President of Bavaria and the leader of the CSU, opposed CDU Chancellor Angela Merkel's policy on Syrian refugees in Germany. Seehofer hoped to place restrictions on incoming refugees, many of whom enter the country through Bavaria. His stance was seen as being in part motivated by the 2018 Bavarian state election in which it was feared that the far-right Alternative for Germany would make gains. The dispute threatened to bring down the Merkel government which relied on the CSU for its parliamentary majority as Seehofer had indicated his resignation on 2 July, but he already rescinded it a day later after an agreement over the issue between the coalition parties (the CDU, the CSU and the SPD) had been reached.


title: CDU/CSU

text: In June 2018, CDU and CSU Bundestag members held separate meetings on the topic of refugees, which was highly unusual. A fake Twitter account announced that CSU leader Seehofer had abolished the CDU/CSU alliance and that CDU vice chair Bouffier had called for a CDU in Bavaria. Many journalists published the news, which was interpreted by the "Merkur" as a sign that such events are considered no longer absurd or unlikely. Political scientist Heinrich Oberreuter did not believe in Seehofer's threat to expand the CSU to the rest of Germany. Both parties aim essentially for the same voters. As separate parties in the general elections both would lose voters. The CSU would lose its unique selling point as a Bavarian party. With a CDU in Bavaria, the CSU would fall from 47 to 30 percent in Bavaria.


title: CDU/CSU

text: A federal CSU was again discussed prior to the general elections of 2021. CSU leader Markus Söder was unhappy about the CDU decision to declare CDU leader Armin Laschet the chancellor candidate and successor of Angela Merkel. In September 2020, the CSU created online memberships for people not living in Bavaria. A survey in May 2021 foresaw that a federal CSU may win at least 9 percent of the votes, especially in Eastern Germany and among FDP voters.


title: CDU/CSU

text: Both parties suffered heavy losses in elections after 2017. In the Bavarian state elections of October 2018, the CSU lost 10.5 percent. With 37.2 percent, this was its worst election result since 1950. In the federal elections of 2021, the CDU lost 7.9 percent and the CSU 1.0 percent of the (party list) votes.


title: CDU/CSU

text: The CDU and the CSU usually only differ slightly in their political stances. The CSU is usually considered more socially conservative (especially on family issues, e.g. the CSU favors providing infants' parents with compensation (Betreuungsgeld) if they intend not to use the public day nursery system to work while the CDU favors public funding of day nurseries). The CSU government in Bavaria has implemented one of the strictest regulations for shopping hours in Germany in order to protect employees. The CSU also strongly opposed ideas of an income unrelated system of contributions to public health insurances, a proposal which met a lot of approval in the CDU in 2010.


title: CDU/CSU

text: CSU politicians often make their mark as self-declared defenders of Bavaria's state rights and cultural independence from federal or European Union bureaucrats, even in times of conservative federal governments or conservative presidents of the European Commission. In 1998, then-Chancellor Helmut Kohl of the CDU had to pressure the CSU intensely not to veto the introduction of the euro as the new currency in Germany. On the other hand, the name euro was the idea of former CSU chairman Theo Waigel, who served as finance minister when the euro was introduced and held a very pro-European position in contrast to the Bavarian government of Edmund Stoiber. Since 2016, the CSU has strongly been advocating the idea of a maximum number (Obergrenze) of 200,000 people per year to limit the number of asylum seekers. This is opposed by the CDU because they claim that it is impossible to limit the number through border control.


title: CDU/CSU

text: While both parties officially identify themselves as non-denominational Christian, the Catholic influence on the CSU is stronger than that on the CDU since Bavaria is predominantly Catholic while Christians in Germany as a whole are approximately equally balanced between Catholics and Protestants. There are nevertheless strong regional differences within Bavaria and Germany as a whole with large predominantly Protestant areas in northern Bavaria and large predominantly Catholic areas in North Rhine-Westphalia and South Western Germany having a strong effect on CDU state politicians. Saarland's former CDU Minister-President Annegret Kramp-Karrenbauer heavily opposed same-sex marriages in July 2017 while the CDU in Schleswig-Holstein was in favor, with Saarland having the largest share of Catholic Christians in any German state.


title: CDU/CSU

text: CDU and CSU are two separate parties with separate organization. While the CDU is a federal party with members and local affiliations in 15 of the 16 German states, the CSU has members and affiliations only in Bavaria. (CSU online members live outside of Bavaria but have no vote within the party.) Also, the CDU is running only in regional and local elections outside of Bavaria. Both parties do have party lists for the general (federal) elections to the Bundestag: the CDU has 15 lists in each of the 15 non Bavarian states, the CSU only in Bavaria.


title: CDU/CSU

text: Since 1972, both parties agreed a joint election manifesto for the federal elections. Sometimes the CSU published additionally a manifesto of its own. Both parties always gather behind a joint candidate for the chancellorship. There is no approved procedure to select this candidate, creating tensions between both parties from time to time. During the federal campaign, the CSU may decide to present mainly Bavarian candidates on the election posters and not the CDU joint chancellor candidate, and the popular candidates of the CDU may decide not to show up in the Bavarian campaign.


title: CDU/CSU

text: Both parties together form a parliamentary group ("Fraktion") in the Bundestag. Such a "Fraktionsgemeinschaft" is legal because both parties are no competition of each other during the elections (the voters can nowhere decide between a CDU and a CSU candidate). The "Fraktionsgemeinschaft" (parliamentary group alliance) works on the basis of a "Fraktionsvertrag" (parliamentary group agreement) with some special provisions for the CSU, e.g. with regard to speaking time in the Bundestag.


title: CDU/CSU

text: The parliamentary group has one chair and one or more vice chairs (12 in the 2021 Bundestag). The chair has always been a CDU member. The First Deputy chair is "ex officio" the leader of the "CSU-Landesgruppe". The "Fraktion" is divided in 16 "Landesgruppen" (state groups), comprising the "Fraktion" members per state. The "CSU-Landesgruppenchef" is considered one of the most prolific members of the Bundestag parliamentary group. Historically, most of these politicians have become members of the federal government.


title: CDU/CSU

text: CDU and CSU always take part in coalition negotiations together, although they behave like two different parties. Both parties join a federal government coalition together; there has never been only one of them in government. At least one major government department is 'given' to the CSU. In the past, the CSU often lead the departments for postal services (when this ministry still existed), transportation, constructions, or agriculture.


title: CDU/CSU

text: In European elections, CDU and CSU have separate party lists. In the European Parliament, they form a group within the parliamentary group of the European People's Party.


title: Curtiss P-36 Hawk

text: The Curtiss P-36 Hawk, also known as the Curtiss Hawk Model 75, is an American-designed and built fighter aircraft of the 1930s and 40s. A contemporary of the Hawker Hurricane and Messerschmitt Bf 109, it was one of the first of a new generation of combat aircraft—a sleek monoplane design with a retractable undercarriage making extensive use of metal in its construction.


title: Curtiss P-36 Hawk

text: Perhaps best known as the predecessor of the Curtiss P-40 Warhawk, the P-36 saw little combat with the United States Army Air Forces during World War II. It was the fighter used most extensively and successfully by the French Air Force during the Battle of France. The P-36 was also ordered by the governments of the Netherlands and Norway but did not arrive in time to see action before both were occupied by Nazi Germany. The type was also manufactured under license in China, for the Republic of China Air Force, as well as in British India, for the Royal Air Force (RAF) and Royal Indian Air Force (RIAF).


title: Curtiss P-36 Hawk

text: Axis and co-belligerent air forces also made significant use of captured P-36s. Following the fall of France and Norway in 1940, several dozen P-36s were seized by Germany and transferred to Finland; these aircraft saw extensive action with the Finnish Air Force against the Soviet Air Forces. The P-36 was also used by Vichy French air forces in several minor conflicts; in one of these, the Franco-Thai War of 1940–41, P-36s were used by both sides.


title: Curtiss P-36 Hawk

text: From mid-1940, some P-36s en route for France and the Netherlands were diverted to Allied air forces in other parts of the world. The Hawks ordered by the Netherlands were diverted to the Dutch East Indies and later saw action against Japanese forces. French orders were taken up by British Commonwealth air forces, and saw combat with the South African Air Force (SAAF) against Italian forces in East Africa, and with the RAF over Burma. Within the Commonwealth, the type was usually referred to as the Curtiss Mohawk.


title: Curtiss P-36 Hawk

text: With around 1,000 aircraft built by Curtiss, the P-36 was a commercial success for the company. It also became the basis of the P-40 and two unsuccessful prototypes: the P-37 and the XP-42.


title: Curtiss P-36 Hawk

text: The Curtiss Model 75 was a private venture by the company, designed by former Northrop Aircraft Company engineer Don R. Berlin. The first prototype, constructed in 1934, featured all-metal construction with fabric-covered control surfaces, a Wright XR-1670-5 radial engine developing , and typical United States Army Air Corps armament of one and one machine gun firing through the propeller arc. Also typical of the time was the total absence of cockpit armor or self-sealing fuel tanks. The distinctive landing gear, which rotated 90° to fold the main wheels flat into the thin trailing portion of the wing, resting atop the lower ends of the maingear struts when retracted, was a Boeing-patented design for which Curtiss had to pay royalties.


title: Curtiss P-36 Hawk

text: The prototype first flew on 6 May 1935, reaching at during early test flights. On 27 May 1935, the prototype was flown to Wright Field, Ohio, to compete in the USAAC fly-off for a new single-seat fighter, but the contest was delayed because the Seversky entry crashed on its way there. Curtiss took advantage of the delay to replace the unreliable engine with a Wright XR-1820-39 Cyclone producing and to rework the fuselage, adding the distinctive scalloped rear windows to improve visibility. The new prototype was designated Model 75B with the R-1670 version retroactively designated Model 75D. The fly-off finally took place in April 1936. Unfortunately, the new engine failed to deliver its rated power and the aircraft only reached .


title: Curtiss P-36 Hawk

text: Although the competing Seversky P-35 also underperformed and was more expensive, it was still declared the winner and awarded a contract for 77 aircraft. However, on 16 June 1936, Curtiss received an order from USAAC for three prototypes designated Y1P-36. The USAAC was concerned about political turmoil in Europe, and about Seversky's ability to deliver P-35s in a timely manner, and therefore wanted a backup fighter. The Y1P-36 (Model 75E) was powered by a 900 hp Pratt & Whitney R-1830-13 Twin Wasp engine, and the scalloped rear canopy was further enlarged. The new aircraft performed so well that it won the 1937 USAAC competition with an order for 210 P-36A fighters.


title: Curtiss P-36 Hawk

text: The aircraft's extremely low wing loading of just 23.9 lb/ft gave it outstanding turning performance, and its high power-to-weight ratio of 0.186 hp/lb gave superb climbing performance for the time. The single speed supercharger was a serious handicap at high altitudes. Compared to the later Allison-engined P-40, the P-36 shared the P-40's traits of excellent high-speed handling, roll rate that improved at high speed, and relatively light controls at high speed. However, it was underpowered, affecting its acceleration and top speed, and it did not accelerate in a dive as well as the P-40.


title: Curtiss P-36 Hawk

text: Argentina bought a number of the simplified, fixed landing gear Hawk 75Os, (intended for rough-field operations and ease of maintenance) and purchased a manufacturing license for the type; 30 were built and delivered by Curtiss, and 20 produced locally. These aircraft used the same engine, Wright Cyclone R-1820-G5 as the Martin 139WAA's and Northrop 8A-2s used by the Argentine Army Aviation at the time. Usually armed with one Madsen machine gun heavily modified for aircraft use and three Madsen light machine guns, there was provision for up to 10 bombs on underwing pylons. The last Argentinian Hawks remained in service until November 1954.


title: Curtiss P-36 Hawk

text: The Royal Air Force (RAF) also displayed interest in the aircraft. Comparison of a borrowed French Hawk 75A-2 with a Supermarine Spitfire Mk I revealed that the Hawk had several advantages over the early variant of the iconic British fighter. The Hawk was found to have lighter controls than the Spitfire at speeds over , especially in diving attacks, and was easier to maneuver in a dogfight (thanks to the less sensitive elevator). The Hawk also had better all-around visibility


title: Curtiss P-36 Hawk

text: and was easier to control on takeoff and landing. Not surprisingly, the Spitfire's superior acceleration and top speed ultimately gave it the advantage of being able to engage and leave combat at will.


title: Curtiss P-36 Hawk

text: Although the British decided not to purchase the aircraft, they soon came into possession of 229 Hawks by way of shipments diverted from occupied France and aircraft flown by escaping French pilots. The aircraft received the designations Mohawk I through IV, mirroring French Hawk 75A-1 through A-4, and were fitted with 0.303-cal. Vickers K machine guns and conventional throttles (forward to increase power).


title: Curtiss P-36 Hawk

text: Although the Hawk was considered obsolete, a number saw service with the RAF and Royal Indian Air Force (RIAF) in India and Burma. In April 1941, the government of British India ordered 48 Cyclone-powered Mohawk IVz (Hawk 75A) for the RIAF, to be built by Hindustan Aircraft. The first such aircraft completed was test flown on 31 July 1942. Only four additional aircraft were completed before the project was abandoned. However, Chinese license production of the Hawk 75A-5 was moved to India, and these aircraft were also absorbed into the RAF/RIAF as Mohawk IVs. They were supplemented by 10 Hawk 75A-9s that were war booty captured in Iran, during the Anglo-Soviet invasion of Iran of August 1941. A further 74 Mohawk IVs that had originally been ordered by France were shipped to India from the United Kingdom. The only RAF units to see combat in Mohawks were No. 5 Squadron RAF and No. 155 Squadron RAF, using the type mainly for Bomber escort and ground attack. The type was retired by the RAF/RIAF in 1944.


title: Curtiss P-36 Hawk

text: The South African Air Force received 72 Mohawks. Its first Mohawks were delivered to East Africa in mid-1941, where they were used by 3 Squadron SAAF to support operations in the East African Campaign, taking part in the Battle of Gondar which ended the campaign, and helping to patrol the border with Vichy French held Djibouti. These Mohawks were then sent to South Africa, where, supplemented by fresh deliveries, they were used for training and for home defence.


title: Curtiss P-36 Hawk

text: The prototype of the Hawk 75H—a simplified version with fixed landing gear, like the 75O—was eventually sold to the Chinese Nationalist government who presented it to Claire L. Chennault for personal use. China also received two similar demonstrators, the Hawk 75Q. They also used a number of simplified Hawk 75Ms against the Japanese. On 11 January 1939, five Hawk 75Ms of the veteran CAF 25th Fighter Squadron led by commander Liu Yijun (劉依鈞) were flown to the new wartime capital of Chongqing in preparations for defense duties there; Liu Yijun and his four specially-trained Hawk 75 pilots all died in the crash of transport aircraft in the return flight. These Hawk 75Ms were intended for the newly established 16th and 18th Fighter Squadrons that were previously light attack-bomber squadrons, but did not supersede the increasingly obsolescent Polikarpov I-15 and I-16 that formed the backbone of most of China's fighter squadrons from 1938 to 1941. The Hawk 75A-5 was built under license in China, but production was later moved to India, and these aircraft were absorbed into the RAF as the Mohawk IV.


title: Curtiss P-36 Hawk

text: After the fall of France, Germany agreed to sell captured Curtiss Hawk fighters to Finland in October 1940. In total, 44 captured aircraft of five subtypes were sold to Finland with three deliveries from 23 June 1941 – 5 January 1944. Not all were from the French stocks, 13 were initially sold to Norway and captured when the Germans conquered that country. The aircraft were given serial codes CU-501 to CU-507 (A-4 submodel with Cyclone) and CU-551 to CU-587 (all other submodels with Twin Wasp).


title: Curtiss P-36 Hawk

text: In Finnish service, the Hawk was well liked, affectionately called "Sussu" ("Sweetheart"). The Finnish Air Force enjoyed success with the type, credited with 190⅓ kills by 58 pilots, between 16 July 1941 and 27 July 1944, for the loss of 15 of their own. Finnish Hawk pilots included the type's highest-scoring ace, Altto Kalevi "Kale" Tervo, with between 14¼ and 15¾ victories in the type; another ace, Kyösti "Kössi" Karhila, scored 12¼ or 13¼ of his 32¼ victories in the Hawk.


title: Curtiss P-36 Hawk

text: The Finnish Hawks were initially armed with either four or six 7.5mm machine guns. While sufficient during the early phase of the Continuation War, the increasing speeds and armor of Soviet aircraft soon showed this armament was not powerful enough. From 1942, the State Aircraft Factory replaced the fuselage machine guns with either one or two Colt or Browning FN machine guns and installed two or four Browning machine guns in each wing. The 12.7mm Berezin UB or LKk/42 heavy machine guns were also used. The installation of heavier armament did not change the very good flying characteristics of the fighter, but the armament was much more effective against Soviet aircraft. The Finnish Hawks were also equipped with Revi 3D or C/12D gunsight.


title: Curtiss P-36 Hawk

text: Surviving Finnish aircraft remained in service with the FAF aviation units HLeLv 13, HLeLv 11 and LeSK until 30 August 1948, when the last operational Finnish Hawks were put into storage. In 1953, the stored aircraft were scrapped.


title: Curtiss P-36 Hawk

text: Even before the P-36A entered production, the French Air Force entered negotiations with Curtiss for delivery of 300 aircraft. The negotiating process ended up being very drawn-out because the cost of the Curtiss fighters was double that of the French Morane-Saulnier M.S.406 and Bloch MB.150, and the delivery schedule was deemed too slow. Since the USAAC was unhappy with the rate of domestic deliveries and believed that export aircraft would slow things down even more, it actively opposed the sale. Eventually, it took direct intervention from U.S. President Franklin Roosevelt to give the French test pilot a chance to fly the Y1P-36.


title: Curtiss P-36 Hawk

text: Detroyat's enthusiasm, problems with the MB.150, and the pressure of continuing German rearmament finally forced France to purchase 100 aircraft and 173 engines. The first Hawk 75A-1 (or H75A-1 n°1) arrived in France in December 1938 and began entering service in March 1939. A few months later, this aircraft was part of "Groupe de Chasse II/5 La Fayette" (heir of the Escadrille Lafayette that fought in France during World War I), wearing the famous Sioux Head on its fuselage side. After the first few examples, aircraft were delivered in pieces and assembled in France by the "Société Nationale de Constructions Aéronautiques du Centre".


title: Curtiss P-36 Hawk

text: Officially designated as the Curtiss H75-C1 (the "Hawk" name was not used in France), the aircraft were powered by Pratt & Whitney R-1830-SC-G engines of 900 hp and had instruments calibrated for the metric system, a seat for French dorsal parachutes, a French-style throttle which operated in reverse from U.S. and British aircraft (full throttle was to the rear rather than to the front) and armament of four (later models had six with two firing through the prop and four in the wings) 7.5 mm FN-Browning machine guns, aimed with a French-supplied Baille-Lemaire gun sight. The aircraft evolved through several modifications, the most significant being the installation of the Wright R-1820 Cyclone engine. The H75-C1 variant saw little operational use due to its late delivery and reliability problems with the Wright radial engine. A total of 316 H75s were delivered to France before the German occupation.


title: Curtiss P-36 Hawk

text: On September 20, Sergeant André-Armand Legrand, pilot of the H75A-1 n°1 in the "Groupe de Chasse II/5 La Fayette" was credited of the first Allied air victory of World War II on the Western front with shooting down a Messerschmitt Bf 109E of the "Luftwaffe" 3/JG 53, over Überherrn. During 1939–1940, French H75 pilots claimed 230 air-to-air kills (of a total of 1,009 air-to-air kills by the French Air Force during 1939–1940) and 81 probable victories in H75s against only 29 aircraft lost in aerial combat. While making up only 12.6 per cent of the French Air Force single-seater fighter force, the H75 accounted for almost a third of the air-to-air kills during the 1940 Battle of France.


title: Curtiss P-36 Hawk

text: Of the 11 French aces of the early part of the war, seven flew H75s. The leading ace of the time was Lieutenant Edmond Marin la Meslée with 15 confirmed and five probable victories in the type. H75-equipped squadrons were evacuated to French North Africa before the Armistice to avoid capture by the Germans. While under the Vichy government, these units clashed with British aircraft during the Battle of Mers El-Kebir and the Battle of Dakar. During Operation Torch in North Africa, French H75s fought against U.S. Navy F4F Wildcats, losing 15 aircraft while shooting down seven American aircraft. From late 1942, the Allies started re-equipping the formerly Vichy-controlled French H75 units with P-40s and P-39s.


title: Curtiss P-36 Hawk

text: A total of 10 Hawk 75A-9s were delivered to Persia, but were captured by the British during the Anglo-Soviet invasion of Iran while still in crates. These were then used by the RAF in India as Mohawk IVs.


title: Curtiss P-36 Hawk

text: In October 1939, the Netherlands ordered 24 Hawk 75A-7s for their colonies of the Dutch East Indies ("Oost Indië"). These planes were powered by 1,200 hp Cyclones. Factory armament was one .50 inch and one .303 inch machine gun in the cowl with two .303 machine guns in the wings. After delivery, the .50 weapons were replaced to standardize parts and ammo. The plane could carry six 23 kg bombs. The fighters were shipped in 1940 and almost rerouted to the Netherlands when Germany invaded. But as the mainland surrendered, the aircraft continued to the colonies where they were used extensively against the Japanese attack on the Far Eastern part of the kingdom. By that time, the aircraft had flown so many hours that the engines were showing serious wear and tear.


title: Curtiss P-36 Hawk

text: Most Dutch Hawks were assigned to the "1ste JachtVliegAfdeling - VliegtuigGroep IV" (1ste JaVA - 1-VlG IV; "1st Fighter Squadron - Flying Group IV") of the Royal Netherlands East Indies Army Air Force (ML-KNIL), although some flew with 1-VlG V. These aircraft saw action over Malacca, Sumatra and Java, successfully bombing the railroad and intercepting bombers and participated in the extensive dogfights over Soerabaja, where USAAF, RAF and ML aircraft fought Japanese bombers and fighters together.


title: Curtiss P-36 Hawk

text: Norway ordered 24 Twin Wasp-powered Hawk 75A-6s, of which 19 were delivered and seven assembled at the time of the German invasion. None of the aircraft were combat-ready. The disassembled aircraft were disabled by a single customs employee who smashed the instruments and cut all the wires he could reach. Thirteen Norwegian Hawks captured by the Germans were part of the first batch of 29 P-36s sent to Finland. Norway also ordered 36 Cyclone-powered Hawk 75A-8s. Most of this batch (a total of 30) were delivered as advanced trainers to "Little Norway" near Toronto, Ontario, Canada, a Norwegian training base established by the London-based government-in-exile. Still later, they were resold to the U.S. and redesignated the P-36G model.


title: Curtiss P-36 Hawk

text: In 1943, the U.S. sent 28 Hawks to Peru under the Lend-Lease agreement. These were ex-Norwegian P-36Gs that had served in Canada.


title: Curtiss P-36 Hawk

text: Portugal was officially neutral during World War II, although the Allies were allowed to use or establish ports and airfields on various Portuguese territories. One result of these friendly relations was the transfer by the British government of 12 Hawk 75A variants to the Portuguese Air Force, or "Força Aérea Portuguesa" (FAP), which assigned them to air defense duties in the Azores.


title: Curtiss P-36 Hawk

text: A few Hawk 75Ns were used by Thailand during the French-Thai War. They also fought at the Battle of Prachuab Khirikhan against Japanese forces during the Japanese Invasion of Thailand. On 28 January 1941, the Royal Thai Air Force (RTAF) dispatched nine Ki-30 Nagoyas, escorted by three Hawk 75s, to bomb Pailin and Sisophon in French Indochina. Thailand was perhaps the only country operating both Japanese and American aircraft just before World War II.


title: Curtiss P-36 Hawk

text: The first production P-36As were delivered to the 20th Pursuit Group at Barksdale Field in Louisiana in April 1938. The aircraft's service history was marred by numerous teething problems with the engine exhaust, skin buckling over landing gear, and weak points in the airframe, severely restricting the performance envelope. By the time these issues were resolved, the P-36 was considered obsolete and was relegated to training units and overseas detachments at Albrook Field in the Panama Canal Zone, Elmendorf Field in Alaska, and Wheeler Field in Hawaii.


title: Curtiss P-36 Hawk

text: The P-36s had been delivered to Hawaii in February 1941 by being loaded on the aircraft carrier USS "Enterprise" in California, then in a first for the USAAC, flown off the carrier's deck by the P-36's U.S. Army Air Corps pilots when the "Enterprise" neared the coast of Hawaii. This saved considerable time over the traditional shipping method of having the fighters first disassembled, crated and then loaded by crane in the hold of a freighter, then unloaded and reassembled in Hawaii.