A cement is a binder, a substance used for construction that sets and adheres to other materials to bind them together. Cement is used on its own, but rather to bind sand and gravel together. Cement mixed with fine aggregate produces mortar for masonry, or with sand and gravel, produces concrete. Cement is the most used material in existence and is only behind water as the planet's most-consumed resource. Cements used in construction are inorganic lime or calcium silicate based, can be characterized as either hydraulic or non-hydraulic, depending on the ability of the cement to set in the presence of water. Non-hydraulic cement does not set under water. Rather, it sets as it reacts with carbon dioxide in the air, it is resistant to attack by chemicals after setting. Hydraulic cements set and become adhesive due to a chemical reaction between the dry ingredients and water; the chemical reaction results in mineral hydrates that are not water-soluble and so are quite durable in water and safe from chemical attack.
This allows setting in wet conditions or under water and further protects the hardened material from chemical attack. The chemical process for hydraulic cement found by ancient Romans used volcanic ash with added lime; the word "cement" can be traced back to the Roman term opus caementicium, used to describe masonry resembling modern concrete, made from crushed rock with burnt lime as binder. The volcanic ash and pulverized brick supplements that were added to the burnt lime, to obtain a hydraulic binder, were referred to as cementum, cimentum, cäment, cement. In modern times, organic polymers are sometimes used as cements in concrete. Non-hydraulic cement, such as slaked lime, hardens by carbonation in the presence of carbon dioxide, present in the air. First calcium oxide is produced from calcium carbonate by calcination at temperatures above 825 °C for about 10 hours at atmospheric pressure: CaCO3 → CaO + CO2The calcium oxide is spent mixing it with water to make slaked lime: CaO + H2O → Ca2Once the excess water is evaporated, the carbonation starts: Ca2 + CO2 → CaCO3 + H2OThis reaction takes time, because the partial pressure of carbon dioxide in the air is low.
The carbonation reaction requires that the dry cement be exposed to air, so the slaked lime is a non-hydraulic cement and cannot be used under water. This process is called the lime cycle. Conversely, hydraulic cement hardens by hydration. Hydraulic cements are made of a mixture of silicates and oxides, the four main components being: Belite; the silicates are responsible for the cement's mechanical properties—the tricalcium aluminate and brownmillerite are essential for formation of the liquid phase during the kiln sintering. The chemistry of these reactions is not clear and is still the object of research; the earliest known occurrence of cement is from twelve million years ago. A deposit of cement was formed after an occurrence of oil shale located adjacent to a bed of limestone burned due to natural causes; these ancient deposits were investigated in the 1970s. Cement, chemically speaking, is a product that includes lime as the primary curing ingredient, but is far from the first material used for cementation.
The Babylonians and Assyrians used bitumen to bind together burnt alabaster slabs. In Egypt stone blocks were cemented together with a mortar made of sand and burnt gypsum, which contained calcium carbonate. Lime was used by the ancient Greeks. There is evidence that the Minoans of Crete used crushed potshards as an artificial pozzolan for hydraulic cement. Nobody knows who first discovered that a combination of hydrated non-hydraulic lime and a pozzolan produces a hydraulic mixture —but such concrete was used by the Ancient Macedonians, three centuries on a large scale by Roman engineers. There is... a kind of powder. It is found in the neighborhood of Baiae and in the country belonging to the towns round about Mt. Vesuvius; this substance when mixed with lime and rubble not only lends strength to buildings of other kinds, but when piers of it are constructed in the sea, they set hard under water. The Greeks used volcanic tuff from the island of Thera as their pozzolan and the Romans used crushed volcanic ash with lime.
This mixture could set under water. The material was called pozzolana from the town of Pozzuoli, west of Naples where volcanic ash was extracted. In the absence of pozzolanic ash, the Romans used powdered brick or pottery as a substitute and they may have used crushed tiles for this purpose before discovering natural sources near Rome; the huge dome of the Pantheon in Rome and the massive Baths of Caracalla are examples of ancient structures made from these concretes, many of which still stand. The vast system of Roman aqueducts made extensive use of hydraulic cement. Roman concrete was used on the outside of buildings; the normal technique was to use brick facing material as the formwork for an infill of mortar mixed with an aggregate of broken pieces of stone, potsherds, recycled chunks of concrete, or other building ru
The German Empire known as Imperial Germany, was the German nation state that existed from the unification of Germany in 1871 until the abdication of Kaiser Wilhelm II in 1918. It was founded in 1871 when the south German states, except for Austria, joined the North German Confederation. On 1 January 1871, the new constitution came into force that changed the name of the federal state and introduced the title of emperor for Wilhelm I, King of Prussia from the House of Hohenzollern. Berlin remained its capital, Otto von Bismarck remained Chancellor, the head of government; as these events occurred, the Prussian-led North German Confederation and its southern German allies were still engaged in the Franco-Prussian War. The German Empire consisted of 26 states, most of them ruled by royal families, they included four kingdoms, six grand duchies, five duchies, seven principalities, three free Hanseatic cities, one imperial territory. Although Prussia was one of several kingdoms in the realm, it contained about two thirds of Germany's population and territory.
Prussian dominance was established constitutionally. After 1850, the states of Germany had become industrialized, with particular strengths in coal, iron and railways. In 1871, Germany had a population of 41 million people. A rural collection of states in 1815, the now united Germany became predominantly urban. During its 47 years of existence, the German Empire was an industrial and scientific giant, gaining more Nobel Prizes in science than any other country. By 1900, Germany was the largest economy in Europe, surpassing the United Kingdom, as well as the second-largest in the world, behind only the United States. From 1867 to 1878/9, Otto von Bismarck's tenure as the first and to this day longest reigning Chancellor was marked by relative liberalism, but it became more conservative afterwards. Broad reforms and the Kulturkampf marked his period in the office. Late in Bismarck's chancellorship and in spite of his personal opposition, Germany became involved in colonialism. Claiming much of the leftover territory, yet unclaimed in the Scramble for Africa, it managed to build the third-largest colonial empire after the British and the French ones.
As a colonial state, it sometimes clashed with other European powers the British Empire. Germany became a great power, boasting a developing rail network, the world's strongest army, a fast-growing industrial base. In less than a decade, its navy became second only to Britain's Royal Navy. After the removal of Otto von Bismarck by Wilhelm II in 1890, the Empire embarked on Weltpolitik – a bellicose new course that contributed to the outbreak of World War I. In addition, Bismarck's successors were incapable of maintaining their predecessor's complex and overlapping alliances which had kept Germany from being diplomatically isolated; this period was marked by various factors influencing the Emperor's decisions, which were perceived as contradictory or unpredictable by the public. In 1879, the German Empire consolidated the Dual Alliance with Austria-Hungary, followed by the Triple Alliance with Italy in 1882, it retained strong diplomatic ties to the Ottoman Empire. When the great crisis of 1914 arrived, Italy left the alliance and the Ottoman Empire formally allied with Germany.
In the First World War, German plans to capture Paris in the autumn of 1914 failed. The war on the Western Front became a stalemate; the Allied naval blockade caused severe shortages of food. However, Imperial Germany had success on the Eastern Front; the German declaration of unrestricted submarine warfare in early 1917, contributed to bringing the United States into the war. The high command under Paul von Hindenburg and Erich Ludendorff controlled the country, but in October after the failed offensive in spring 1918, the German armies were in retreat, allies Austria-Hungary and the Ottoman Empire had collapsed, Bulgaria had surrendered; the Empire collapsed in the November 1918 Revolution with the abdications of its monarchs. This left a postwar federal republic and a devastated and unsatisfied populace, which led to the rise of Adolf Hitler and Nazism; the German Confederation had been created by an act of the Congress of Vienna on 8 June 1815 as a result of the Napoleonic Wars, after being alluded to in Article 6 of the 1814 Treaty of Paris.
German nationalism shifted from its liberal and democratic character in 1848, called Pan-Germanism, to Prussian prime minister Otto von Bismarck's pragmatic Realpolitik. Bismarck sought to extend Hohenzollern hegemony throughout the German states, he envisioned a Prussian-dominated Germany. Three wars led to military successes and helped to persuade German people to do this: the Second Schleswig War against Denmark in 1864, the Austro-Prussian War in 1866, the Franco-Prussian War against France in 1870–71; the German Confederation ended as a result of the Austro-Prussian War of 1866 between the constituent Confederation entities of the Austrian Empire and its allies on one side and the Kingdom of Prussia and its allies on the other. The war resulted in the partial replacement of the Confederation in 1867 by a North German Confederation, comprising the 22 states north of the Main; the patriotic fervour generated by the Franco-Prussian War overwhelmed the remaining opposition to a unified Germany in the four stat
Hamburg is the second-largest city in Germany with a population of over 1.8 million. One of Germany's 16 federal states, it is surrounded by Schleswig-Holstein to the north and Lower Saxony to the south; the city's metropolitan region is home to more than five million people. Hamburg lies on two of its tributaries, the River Alster and the River Bille; the official name reflects Hamburg's history as a member of the medieval Hanseatic League and a free imperial city of the Holy Roman Empire. Before the 1871 Unification of Germany, it was a sovereign city state, before 1919 formed a civic republic headed constitutionally by a class of hereditary grand burghers or Hanseaten. Beset by disasters such as the Great Fire of Hamburg, north Sea flood of 1962 and military conflicts including World War II bombing raids, the city has managed to recover and emerge wealthier after each catastrophe. Hamburg is Europe's third-largest port. Major regional broadcasting firm NDR, the printing and publishing firm Gruner + Jahr and the newspapers Der Spiegel and Die Zeit are based in the city.
Hamburg is the seat of Germany's oldest stock exchange and the world's oldest merchant bank, Berenberg Bank. Media, commercial and industrial firms with significant locations in the city include multinationals Airbus, Blohm + Voss, Aurubis and Unilever; the city hosts specialists in world economics and international law, including consular and diplomatic missions as the International Tribunal for the Law of the Sea, the EU-LAC Foundation, the UNESCO Institute for Lifelong Learning, multipartite international political conferences and summits such as Europe and China and the G20. Both the former German Chancellor Helmut Schmidt and Angela Merkel, German chancellor since 2005, come from Hamburg; the city is a major domestic tourist destination. It ranked 18th in the world for livability in 2016; the Speicherstadt and Kontorhausviertel were declared World Heritage Sites by UNESCO in 2015. Hamburg is a major European science and education hub, with several universities and institutions. Among its most notable cultural venues are the Laeiszhalle concert halls.
It paved the way for bands including The Beatles. Hamburg is known for several theatres and a variety of musical shows. St. Pauli's Reeperbahn is among the best-known European entertainment districts. Hamburg is at a sheltered natural harbour on the southern fanning-out of the Jutland Peninsula, between Continental Europe to the south and Scandinavia to the north, with the North Sea to the west and the Baltic Sea to the northeast, it is on the River Elbe at its confluence with the Bille. The city centre is around the Binnenalster and Außenalster, both formed by damming the River Alster to create lakes; the islands of Neuwerk, Scharhörn, Nigehörn, 100 kilometres away in the Hamburg Wadden Sea National Park, are part of the city of Hamburg. The neighborhoods of Neuenfelde, Cranz and Finkenwerder are part of the Altes Land region, the largest contiguous fruit-producing region in Central Europe. Neugraben-Fischbek has Hamburg's highest elevation, the Hasselbrack at 116.2 metres AMSL. Hamburg borders the states of Lower Saxony.
Hamburg has an oceanic climate, influenced by its proximity to the coast and marine air masses that originate over the Atlantic Ocean. The location north of Germany provides extremes greater than marine climates, but in the category due to the mastery of the western standards. Nearby wetlands enjoy a maritime temperate climate; the amount of snowfall has differed a lot during the past decades: while in the late 1970s and early 1980s, at times heavy snowfall occurred, the winters of recent years have been less cold, with snowfall only on a few days per year. The warmest months are June and August, with high temperatures of 20.1 to 22.5 °C. The coldest are December and February, with low temperatures of −0.3 to 1.0 °C. Claudius Ptolemy reported the first name for the vicinity as Treva; the name Hamburg comes from the first permanent building on the site, a castle which the Emperor Charlemagne ordered constructed in AD 808. It rose on rocky terrain in a marsh between the River Alster and the River Elbe as a defence against Slavic incursion, acquired the name Hammaburg, burg meaning castle or fort.
The origin of the Hamma term remains uncertain. In 834, Hamburg was designated as the seat of a bishopric; the first bishop, became known as the Apostle of the North. Two years Hamburg was united with Bremen as the Bishopric of Hamburg-Bremen. Hamburg occupied several times. In 845, 600 Viking ships sailed up the River Elbe and destroyed Hamburg, at that time a town of around 500 inhabitants. In 1030, King Mieszko II Lambert of Poland burned down the city. Valdemar II of Denmark raided and occupied Hamburg in 1201 and in 1214; the Black Death killed at least 60% of the population in 1350. Hamburg experienced several great fires in the medieval period. In 1189, by imperial charter, Frederick I "Barbarossa" granted Hamburg the status of a Free Imperial City and tax-free access up the Lower Elbe into the North Sea. In 1265, an forged letter was presented to or by the Rath of Hamburg; this charter, along with Hamburg's proximity to the main trade routes of the North Sea and Baltic Sea made it a
The United States of America known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U. S. is the third most populous country. The capital is Washington, D. C. and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico; the State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean; the U. S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The diverse geography and wildlife of the United States make it one of the world's 17 megadiverse countries.
Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago. European colonization began in the 16th century; the United States emerged from the thirteen British colonies established along the East Coast. Numerous disputes between Great Britain and the colonies following the French and Indian War led to the American Revolution, which began in 1775, the subsequent Declaration of Independence in 1776; the war ended in 1783 with the United States becoming the first country to gain independence from a European power. The current constitution was adopted in 1788, with the first ten amendments, collectively named the Bill of Rights, being ratified in 1791 to guarantee many fundamental civil liberties; the United States embarked on a vigorous expansion across North America throughout the 19th century, acquiring new territories, displacing Native American tribes, admitting new states until it spanned the continent by 1848. During the second half of the 19th century, the Civil War led to the abolition of slavery.
By the end of the century, the United States had extended into the Pacific Ocean, its economy, driven in large part by the Industrial Revolution, began to soar. The Spanish–American War and World War I confirmed the country's status as a global military power; the United States emerged from World War II as a global superpower, the first country to develop nuclear weapons, the only country to use them in warfare, a permanent member of the United Nations Security Council. Sweeping civil rights legislation, notably the Civil Rights Act of 1964, the Voting Rights Act of 1965 and the Fair Housing Act of 1968, outlawed discrimination based on race or color. During the Cold War, the United States and the Soviet Union competed in the Space Race, culminating with the 1969 U. S. Moon landing; the end of the Cold War and the collapse of the Soviet Union in 1991 left the United States as the world's sole superpower. The United States is the world's oldest surviving federation, it is a representative democracy.
The United States is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, other international organizations. The United States is a developed country, with the world's largest economy by nominal GDP and second-largest economy by PPP, accounting for a quarter of global GDP; the U. S. economy is post-industrial, characterized by the dominance of services and knowledge-based activities, although the manufacturing sector remains the second-largest in the world. The United States is the world's largest importer and the second largest exporter of goods, by value. Although its population is only 4.3% of the world total, the U. S. holds 31% of the total wealth in the world, the largest share of global wealth concentrated in a single country. Despite wide income and wealth disparities, the United States continues to rank high in measures of socioeconomic performance, including average wage, human development, per capita GDP, worker productivity.
The United States is the foremost military power in the world, making up a third of global military spending, is a leading political and scientific force internationally. In 1507, the German cartographer Martin Waldseemüller produced a world map on which he named the lands of the Western Hemisphere America in honor of the Italian explorer and cartographer Amerigo Vespucci; the first documentary evidence of the phrase "United States of America" is from a letter dated January 2, 1776, written by Stephen Moylan, Esq. to George Washington's aide-de-camp and Muster-Master General of the Continental Army, Lt. Col. Joseph Reed. Moylan expressed his wish to go "with full and ample powers from the United States of America to Spain" to seek assistance in the revolutionary war effort; the first known publication of the phrase "United States of America" was in an anonymous essay in The Virginia Gazette newspaper in Williamsburg, Virginia, on April 6, 1776. The second draft of the Articles of Confederation, prepared by John Dickinson and completed by June 17, 1776, at the latest, declared "The name of this Confederation shall be the'United States of America'".
The final version of the Articles sent to the states for ratification in late 1777 contains the sentence "The Stile of this Confederacy shall be'The United States of America'". In June 1776, Thomas Jefferson wrote the phrase "UNITED STATES OF AMERICA" in all capitalized letters in the headline of his "original Rough draught" of the Declaration of Independence; this draft of the document did not surface unti
Aerial victory standards of World War I
During World War I, the national air services involved developed their own methods of assessing and assigning credit for aerial victories. The victory scores of the pilots represented at List of World War I flying aces cannot be definitive, but are based on itemized lists that are the best available sources of information. Loss of records, by mischance and the passage of time – and the detail to which such records were kept in the first place – complicates the reconstruction of the actual count for a given ace. Additionally, the German victory confirmation system began to buckle in February 1918. World War I began the historical experience that has shown that five percent of combat pilots account for the majority of air-to-air victories in warfare, thus showing the importance of flying aces. Enemy aircraft had to fall within friendly lines in a nation occupied by the enemy, or be seen by friendly ground troops falling within German lines, to be counted. Confirmation by fellow friendly pilots was not allowed.
Thus, unconfirmed claims outnumbered official victories. Although the Belgian system of counting victories mirrored the French system more than the British one, victory lists for Belgian aces still contain confirmed claims for FTL and OOC victories. Inspection of the Belgian pilots' victory lists show victories being shared without being fractionally divided. French victory confirmation standards were strict. Credit was given only for the destruction of an enemy aircraft, the destruction had to be witnessed by an independent witness, such as an artillery observer, infantryman, or another pilot; the victories certified fell into one of four categories of destruction: An enemy aircraft independently witnessed falling in flames. Probable victories would not count on a pilot's score. Examples of probable victories could be enemy aircraft falling out of control but not seen to impact, or a claim lacking independent confirmation. Observers as well as pilots could become aces. Victories could be shared, counted as an addition of one to the score of each'victor' rather than being divided fractionally.
In some cases, a single destroyed German or Austro-Hungarian aircraft could add to the scores of half a dozen or more French fliers. Counting of "aerial victories" by the British was shaped by the high command’s determination to sustain an ongoing aerial offensive, as well as the prevailing westerly winds on the Western Front. From the start, the British counted actions, their count system was skewed toward recognizing the moral victory of thwarting enemy offensive actions as well as the physical one of destroying his aircraft. A British or Commonwealth pilot of the Royal Flying Corps and Royal Naval Air Service, or Australian pilots of the Australian Flying Corps could be credited with a victory for destroying an enemy plane, for driving it down out of control, capturing it, or destroying an enemy observation balloon. In the earliest days of aerial combat, in 1915 and 1916, victories could be awarded for forcing an enemy aircraft to land in either Allied or enemy territory. By 1917, the number of "out of control", "driven down" and "forced to land" victories were overloading the scoring system.
As aerial combat soared to the point where British pilots might submit 50 claims on a given day, the count system became overwhelmed. By May 1918, the new Royal Air Force ceased reporting "out of control" victories as part of pilots' scores, but still credited them to pilots for the purposes of awarding decorations. Victories were limited to enemy aircraft destroyed, enemy airplanes driven down out of control if they seemed so damaged they would crash, airplanes captured. Squadron and Wing headquarters all kept track of individual and unit scores; the approval system began with a Combat Report from the Squadron submitted to Wing HQ. They in turn passed the report on to Brigade HQ. Either Wing or Brigade could disapprove it. Victories were reported by RFC HQ via Communiqué; the deadline for the daily Communiqué was 1600 hours. Following a system that did not always report an event on the day it occurred added to the confusion caused by dual reporting. In cases where more than one pilot was involved in a British victory, practice was inconsistent.
Since after all only one enemy aircraft had been destroyed, the victory at unit level was counted as one. On the other hand, in some cases all pilots concerned might receive a full credit to his personal score, as victories at this time were not divided fractionally, in the way that became common practice later; as a striking example of this, no fewer than twelve Royal Flying Corps pilots each claimed a victory because they helped destroy an Albatros D. III on 8 April 1917. However, some squadrons counted such victories only to the unit concerned without crediting them to an individual, or counted "shared" scores separately from a particular pilot’s'solo' victories. In the case of two-seater crews, both pilot and observer might each receive credit for a victory; the usual rule of thumb credited all
The Luftwaffe was the aerial warfare branch of the combined German Wehrmacht military forces during World War II. Germany's military air arms during World War I, the Luftstreitkräfte of the Army and the Marine-Fliegerabteilung of the Navy, had been disbanded in May 1920 as a result of the terms of the Treaty of Versailles which stated that Germany was forbidden to have any air force. During the interwar period, German pilots were trained secretly in violation of the treaty at Lipetsk Air Base. With the rise of the Nazi Party and the repudiation of the Versailles Treaty, the Luftwaffe was established on 26 February 1935, just over a fortnight before open defiance of the Versailles Treaty through German re-armament and conscription would be announced on March 16; the Condor Legion, a Luftwaffe detachment sent to aid Nationalist forces in the Spanish Civil War, provided the force with a valuable testing ground for new tactics and aircraft. As a result of this combat experience, the Luftwaffe had become one of the most sophisticated, technologically advanced, battle-experienced air forces in the world when World War II broke out in 1939.
By the summer of 1939, the Luftwaffe had twenty-eight Geschwader. The Luftwaffe operated Fallschirmjäger paratrooper units; the Luftwaffe proved instrumental in the German victories across Poland and Western Europe in 1939 and 1940. During the Battle of Britain, despite inflicting severe damage to the RAF's infrastructure and, during the subsequent Blitz, devastating many British cities, the German air force failed to batter the beleaguered British into submission. From 1942, Allied bombing campaigns destroyed the Luftwaffe's fighter arm. From late 1942, the Luftwaffe used its surplus ground and other personnel to raise Luftwaffe Field Divisions. In addition to its service in the West, the Luftwaffe operated over the Soviet Union, North Africa and Southern Europe. Despite its belated use of advanced turbojet and rocket propelled aircraft for the destruction of Allied bombers, the Luftwaffe was overwhelmed by the Allies' superior numbers and improved tactics, a lack of trained pilots and aviation fuel.
In January 1945, during the closing stages of the Battle of the Bulge, the Luftwaffe made a last-ditch effort to win air superiority, met with failure. With dwindling supplies of petroleum and lubricants after this campaign, as part of the entire combined Wehrmacht military forces as a whole, the Luftwaffe ceased to be an effective fighting force. After the defeat of Germany, the Luftwaffe was disbanded in 1946. During World War II, German pilots claimed 70,000 aerial victories, while over 75,000 Luftwaffe aircraft were destroyed or damaged. Of these, nearly 40,000 were lost entirely; the Luftwaffe had only two commanders-in-chief throughout its history: Hermann Göring and Generalfeldmarschall Robert Ritter von Greim for the last two weeks of the war. The Luftwaffe was involved in Nazi war crimes. By the end of the war, a significant percentage of aircraft production originated in concentration camps, an industry employing tens of thousands of prisoners; the Luftwaffe's demand for labor was one of the factors that led to the deportation and murder of hundreds of thousands of Hungarian Jews in 1944.
The Luftwaffe High Command organized Nazi human experimentation, Luftwaffe ground troops committed massacres in Italy and Poland. The Imperial German Army Air Service was founded in 1910 with the name Die Fliegertruppen des deutschen Kaiserreiches, most shortened to Fliegertruppe, it was renamed Luftstreitkräfte on 8 October 1916. The air war on the Western Front received the most attention in the annals of the earliest accounts of military aviation, since it produced aces such as Manfred von Richthofen and Ernst Udet, Oswald Boelcke, Max Immelmann. After the defeat of Germany, the service was dissolved on 8 May 1920 under the conditions of the Treaty of Versailles, which mandated the destruction of all German military aircraft. Since the Treaty of Versailles forbade Germany to have an air force, German pilots trained in secret. Civil aviation schools within Germany were used, yet only light trainers could be used in order to maintain the façade that the trainees were going to fly with civil airlines such as Deutsche Luft Hansa.
To train its pilots on the latest combat aircraft, Germany solicited the help of the Soviet Union, isolated in Europe. A secret training airfield was established at Lipetsk in 1924 and operated for nine years using Dutch and Soviet, but some German, training aircraft before being closed in 1933; this base was known as 4th squadron of the 40th wing of the Red Army. Hundreds of Luftwaffe pilots and technical personnel visited and were trained at Soviet air force schools in several locations in Central Russia. Roessing, Fosse, Heini, Makratzki and many other future Luftwaffe aces were trained in Russia in joint Russian-German schools that were set up under the patronage of Ernst August Köstring; the first steps towards the Luftwaffe's formation were undertaken just months after Adolf Hitler came to power. Hermann Göring, a World War I ace, became National Kommissar for aviation with former Luft Hansa director Erhard Milch as his deputy. In April 1933 the Reich Aviation Ministry was established; the RLM was in charge of production of aircraft.
Göring's control over all aspects of aviation became absolute. On 25 March 1933 the German Air Sports Association absorbed all private and national organizations, while retaining its'sports' title. On 15 May 1933, all military aviation organizations in th
Leutnant is the lowest Lieutenant officer rank in the armed forces of Germany, Austrian Armed Forces, military of Switzerland. The German noun (with the meaning “Stellvertreter” from Middle High German «locum tenens» Platzhalter was derived from the French word «Lieutenant» about 1500. In most German-speaking armies it is the lowest officer rank (in German-speaking navies «Leutnant zur See». In the German Bundeswehr the ranks Leutnant OF1b and Oberleutnant OF1a belong to the Leutnant rank group. In some other armed forces there is the lower grade of Unterleutnant. From about 1500 until the middle of the 17th century the designation of «Leutnant» was used for any deputy to a commanding officer. So at the army level there was the appointment of General-Leutnant, at the regimental level there was that of Oberst-Leutnant, at the company level the Leutnant was deputy to a Hauptmann. With the formation of standing armies in the second half of the 17th century, the term came to designate the rank of the least senior commissioned officer.
In the 18th and 19th century, at the unit level several Leutnants served as platoon leaders. At that time the ranks of Premier-Lieutenant and Seconde-Lieutenant came into existence. With effect from January 1, 1899 in the German Empire these ranks were renamed as Oberleutnant and Leutnant; the term «Leutnant» has been used in German armed forces since 1899. In the Bundeswehr today the «Leutnant» will be appointed as platoon leader. However, the rank of «Leutnant» might be held while a junior officer is studying at the University of the German Federal Armed Forces or at another training or education establishment; the «Leutnant» of the Bundeswehr belongs to the Leutnant’s rank group. In Germany Leutnant is the designation of a soldier of the lowest officer rank; the equivalent in the German Navy is the Leutnant zur See. Soldiers with that particular OF1b-rank, are mandated and authorized to provide military orders as to the so-called Superior-subordinate relations to private ranks, NCOs without port épée, as well as to Senior NCOs with port épée.
In the GDR National People's Army the OF1b-rank Leutnant was the second lowest commissioned offer rank until 1990. This was in reference to Soviet military doctrine and in line with other armed forces of the Warsaw Pact; the equivalent rank of the Volksmarine was the Leutnant zur See called Leutnant for short. In reference to the Soviet armed forces and to other armed forces of the Warsaw pact Leutnant was the second lowest officer rank until 1990. In Nazi Germany, within the SS and Waffen-SS, the rank of SS-Untersturmführer was considered to be the equivalent of an Leutnant in the German Army. However, in the SA the equivalent to Leutnant was SA-Sturmführer. In Austria the Leutnant is the second lowest CO rank. Mandatory to be promoted to that OF1b-rank is a six terms course of high school studies with 180 ECTS points on the Theresian Military Academy in the Wiener Neustadt; the studies are focused on “Military Command and Control” and the academy-leaver graduate to Bachelor. The career in the Militia is structured in a different way.
Here the modular education comprises the so-called one-year volunteer year as well as several courses and exercises with a final aptitude test. After an overall service time of five years the promotion to «Leutnant» is possible. Moreover, the appointment designation «Leutnant» is possible for leading officials of the Austrian executive, e.g. the Austrian Federal Police and prison authority personnel. Until 1918 Leutnant was in the Austria-Hungarian Army the lowest CO-rank as well, equivalent to Assistenz-Arzt and Leutnant-Rechnungsführer. In the military of Switzerland the Leutnant is a commissioned officer rank. At the contrary to the so-called Army-95 time a Leutnant / platoon leader might not be promoted to Oberleutnant automatically. However, he remains Leutnant during two reiteration courses. In United Nations missions and in NATO Partnership for Peace the rank Leutnant will be designated in English with Second lieutenant, NATO-Code: OF-1b. Die Streitkräfte der Republik Österreich, 1918-1968, Heeresgeschichtliches Museum, Militärwissenschaftliches Institut, 1968