sentence-transformers/squad huggingface dataset:
Passage: The term air defence was probably first used by Britain when Air Defence of Great Britain (ADGB) was created as a Royal Air Force command in 1925. However, arrangements in the UK were also called 'anti-aircraft', abbreviated as AA, a term that remained in general use into the 1950s. After the First World War it was sometimes prefixed by 'Light' or 'Heavy' (LAA or HAA) to classify a type of gun or unit. Nicknames for anti-aircraft guns include AA, AAA or triple-A, an abbreviation of anti-aircraft artillery; "ack-ack" (from the spelling alphabet used by the British for voice transmission of "AA"); and archie (a World War I British term probably coined by Amyas Borton and believed to derive via the Royal Flying Corps from the music-hall comedian George Robey's line "Archibald, certainly not!").

Question: Which country probably coined the term air defence?

Question: What does ADGB stand for?

Question: What year was the ADGB created?

Question: Who is probably the one who coined the term archie for anti-aircraft guns?

Question: What George Robey line is believed to have started the archie nickname?
Passage: The essence of air defence is to detect hostile aircraft and destroy them. The critical issue is to hit a target moving in three-dimensional space; an attack must not only match these three coordinates, but must do so at the time the target is at that position. This means that projectiles either have to be guided to hit the target, or aimed at the predicted position of the target at the time the projectile reaches it, taking into account speed and direction of both the target and the projectile.

Question: What is the first purpose of air defence?

Question: What is the second purpose of air defence?

Question: What is the critical issue in air defence?

Question: Projectiles must either be guided to the target or aimed where?

Question: What two things must be considered in regards to the projectile and target?
Passage: Passive air defence is defined by NATO as "Passive measures taken for the physical defence and protection of personnel, essential installations and equipment in order to minimize the effectiveness of air and/or missile attack". It remains a vital activity by ground forces and includes camouflage and concealment to avoid detection by reconnaissance and attacking aircraft. Measures such as camouflaging important buildings were common in the Second World War. During the Cold War the runways and taxiways of some airfields were painted green.

Question: What does NATO define as passive measures to protect people, buildings and equipment from air or missile attacks?

Question: Which group is heavily responsible for passive air defence?

Question: Passive air defence includes camouflage and what?

Question: What was camouflaged during World War II?

Question: Some airfield runways were painted green during what war?
Passage: The basic air defence unit is typically a battery with 2 to 12 guns or missile launchers and fire control elements. These batteries, particularly with guns, usually deploy in a small area, although batteries may be split; this is usual for some missile systems. SHORAD missile batteries often deploy across an area with individual launchers several kilometres apart. When MANPADS is operated by specialists, batteries may have several dozen teams deploying separately in small sections; self-propelled air defence guns may deploy in pairs.

Question: How many guns or missile launchers are typically in a battery?

Question: In addition to guns or missile launchers, what else comprises the battery?

Question: Where do batteries typically get deployed?

Question: Which missile batteries often have individual launchers several kilometres from one another?

Question: Several dozen teams can deploy individually in small sections when what is handled by a specialist?
Passage: The first issue was ammunition. Before the war it was recognised that ammunition needed to explode in the air. Both high explosive (HE) and shrapnel were used, mostly the former. Airburst fuses were either igniferious (based on a burning fuse) or mechanical (clockwork). Igniferious fuses were not well suited for anti-aircraft use. The fuse length was determined by time of flight, but the burning rate of the gunpowder was affected by altitude. The British pom-poms had only contact-fused ammunition. Zeppelins, being hydrogen filled balloons, were targets for incendiary shells and the British introduced these with airburst fuses, both shrapnel type-forward projection of incendiary 'pot' and base ejection of an incendiary stream. The British also fitted tracers to their shells for use at night. Smoke shells were also available for some AA guns, these bursts were used as targets during training.

Question: It was understood that ammunition needed to explode where?

Question: In addition to high explosive, what else was used?

Question: Airburst fuses could be which two things?

Question: What were hydrogen filled balloons called?

Question: What was used as targets in training practices?
Passage: Two assumptions underpinned the British approach to HAA fire; first, aimed fire was the primary method and this was enabled by predicting gun data from visually tracking the target and having its height. Second, that the target would maintain a steady course, speed and height. This HAA was to engage targets up to 24,000 feet. Mechanical, as opposed to igniferous, time fuses were required because the speed of powder burning varied with height so fuse length was not a simple function of time of flight. Automated fire ensured a constant rate of fire that made it easier to predict where each shell should be individually aimed.

Question: What was the primary method for HAA fire?

Question: Along with predicting the gun data from tracking the target, what else needed to be known about the target to enable the aimed fire?

Question: Another assumption was that the target would maintain a steady course along with what other two factors?

Question: Targets could be how many feet for the HAA to engage them?

Question: What kind of fuses were needed?
Passage: The US ended World War I with two 3-inch AA guns and improvements were developed throughout the inter-war period. However, in 1924 work started on a new 105 mm static mounting AA gun, but only a few were produced by the mid-1930s because by this time work had started on the 90 mm AA gun, with mobile carriages and static mountings able to engage air, sea and ground targets. The M1 version was approved in 1940. During the 1920s there was some work on a 4.7-inch which lapsed, but revived in 1937, leading to a new gun in 1944.

Question: When were improvements developed for these guns?

Question: What year was the M1 version approved?

Question: Only a few of the 105 mm static mounting AA guns were produced because work had started on which other gun?

Question: When did work begin on the 105 mm static mounting AA gun?

Question: What kind of guns did the United States end WW I with?
Passage: In some countries, such as Britain and Germany during the Second World War, the Soviet Union and NATO's Allied Command Europe, ground based air defence and air defence aircraft have been under integrated command and control. However, while overall air defence may be for homeland defence including military facilities, forces in the field, wherever they are, invariably deploy their own air defence capability if there is an air threat. A surface-based air defence capability can also be deployed offensively to deny the use of airspace to an opponent.

Question: Which country's air defence and aircraft has been under integrated command and control?

Question: What other group has also been under this integrated command and control?

Question: Who will deploy their own air defence if their is an air threat?

Question: What can be deployed as an offensive measure to refuse airspace use to an opponent?
Passage: After World War I the US Army started developing a dual-role (AA/ground) automatic 37 mm cannon, designed by John M. Browning. It was standardised in 1927 as the T9 AA cannon, but trials quickly revealed that it was worthless in the ground role. However, while the shell was a bit light (well under 2 lbs) it had a good effective ceiling and fired 125 rounds per minute; an AA carriage was developed and it entered service in 1939. The Browning 37mm proved prone to jamming, and was eventually replaced in AA units by the Bofors 40 mm. The Bofors had attracted attention from the US Navy, but none were acquired before 1939. Also, in 1931 the US Army worked on a mobile anti-aircraft machine mount on the back of a heavy truck having four .30 caliber water-cooled machine guns and an optical director. It proved unsuccessful and was abandoned.

Question: What did the United States Army begin to develop after the first World War?

Question: Who designed this cannon?

Question: How many rounds did this cannon fire per second?

Question: What replaced the Browning 37nn because of jamming issues?

Question: What other US group was interested in the Bofors?
Passage: Germany's high-altitude needs were originally going to be filled by a 75 mm gun from Krupp, designed in collaboration with their Swedish counterpart Bofors, but the specifications were later amended to require much higher performance. In response Krupp's engineers presented a new 88 mm design, the FlaK 36. First used in Spain during the Spanish Civil War, the gun proved to be one of the best anti-aircraft guns in the world, as well as particularly deadly against light, medium, and even early heavy tanks.

Question: High altitude needs in Germany were going to be handled by what?

Question: Who also collaborated in the design of the 75 mm gun?

Question: Because higher performance was needed, Krupp's workers designed what?

Question: Where was the first place the FlaK 36 was used?

Question: What war was the FlaK first used in?
Passage: A plethora of anti-aircraft gun systems of smaller calibre were available to the German Wehrmacht combined forces, and among them the 1940-origin Flakvierling quadruple-20 mm-gun antiaircraft weapon system was one of the most often-seen weapons, seeing service on both land and sea. The similar Allied smaller-calibre air-defence weapons systems of the American forces were also quite capable, although they receive little attention. Their needs could cogently be met with smaller-calibre ordnance beyond using the usual singly-mounted M2 .50 caliber machine gun atop a tank's turret, as four of the ground-used "heavy barrel" (M2HB) guns were mounted together on the American Maxson firm's M45 Quadmount weapons system (as a direct answer to the Flakvierling),which were often mounted on the back of a half-track to form the Half Track, M16 GMC, Anti-Aircraft. Although of less power than Germany's 20 mm systems, the typical 4 or 5 combat batteries of an Army AAA battalion were often spread many kilometers apart from each other, rapidly attaching and detaching to larger ground combat units to provide welcome defence from enemy aircraft.

Question: What was one of the most often seen weapons that was used both on land and sea?

Question: What weapons system did American troops use but received minute attention?

Question: How many of the M2HB guns were mounted together on the M45 Quadmount weapons system?

Question: This system was a direct answer to what?

Question: The combat batteries of an Army AAA battalion were often spread how far apart from each other?
Passage: Another aspect of anti-aircraft defence was the use of barrage balloons to act as physical obstacle initially to bomber aircraft over cities and later for ground attack aircraft over the Normandy invasion fleets. The balloon, a simple blimp tethered to the ground, worked in two ways. Firstly, it and the steel cable were a danger to any aircraft that tried to fly among them. Secondly, to avoid the balloons, bombers had to fly at a higher altitude, which was more favorable for the guns. Barrage balloons were limited in application, and had minimal success at bringing down aircraft, being largely immobile and passive defences.

Question: What acted as a physical obstacle to anti-aircraft defence?

Question: What were barrage balloons initially used as an obstacle to?

Question: How was a barrage balloon tethered to the ground?

Question: What did pilots have to do to avoid the barrage balloons?

Question: What kind of success did barrage balloons have as far as bringing down aircraft?
Passage: The maximum distance at which a gun or missile can engage an aircraft is an important figure. However, many different definitions are used but unless the same definition is used, performance of different guns or missiles cannot be compared. For AA guns only the ascending part of the trajectory can be usefully used. One term is 'ceiling', maximum ceiling being the height a projectile would reach if fired vertically, not practically useful in itself as few AA guns are able to fire vertically, and maximum fuse duration may be too short, but potentially useful as a standard to compare different weapons.

Question: What is an important number when it comes to guns engaging an aircraft?

Question: What can be used to determine the maximum distance for an AA gun?

Question: What is the term used to describe the height that a projectile would go to if it was fired vertically?

Question: Few AA guns are able to fire which way?
Passage: As this process continued, the missile found itself being used for more and more of the roles formerly filled by guns. First to go were the large weapons, replaced by equally large missile systems of much higher performance. Smaller missiles soon followed, eventually becoming small enough to be mounted on armored cars and tank chassis. These started replacing, or at least supplanting, similar gun-based SPAAG systems in the 1960s, and by the 1990s had replaced almost all such systems in modern armies. Man-portable missiles, MANPADs as they are known today, were introduced in the 1960s and have supplanted or even replaced even the smallest guns in most advanced armies.

Question: The missile started being used more often instead of what weapon?

Question: Small missiles were designed that could be mounted on what?

Question: When did these missiles start to supplant gun-based SPAAG systems?

Question: What are man-portable missiles better known as?

Question: When were MANPADs introduced?
Passage: Unlike the heavier guns, these smaller weapons are in widespread use due to their low cost and ability to quickly follow the target. Classic examples of autocannons and large caliber guns are the 40 mm autocannon and the 8.8 cm FlaK 18, 36 gun, both designed by Bofors of Sweden. Artillery weapons of this sort have for the most part been superseded by the effective surface-to-air missile systems that were introduced in the 1950s, although they were still retained by many nations. The development of surface-to-air missiles began in Nazi Germany during the late World War II with missiles such as the Wasserfall, though no working system was deployed before the war's end, and represented new attempts to increase effectiveness of the anti-aircraft systems faced with growing threat from [bomber]s. Land-based SAMs can be deployed from fixed installations or mobile launchers, either wheeled or tracked. The tracked vehicles are usually armoured vehicles specifically designed to carry SAMs.

Question: Smaller weapons are able to be used because of their low cost as well as what other factor?

Question: Who designed the 40 mm autocannon?

Question: When were the surface-to-air missile systems introduced?

Question: Where were surface-to-air missiles first developed?

Question: How can land-based SAMs be deployed?
Passage: Smaller boats and ships typically have machine-guns or fast cannons, which can often be deadly to low-flying aircraft if linked to a radar-directed fire-control system radar-controlled cannon for point defence. Some vessels like Aegis cruisers are as much a threat to aircraft as any land-based air defence system. In general, naval vessels should be treated with respect by aircraft, however the reverse is equally true. Carrier battle groups are especially well defended, as not only do they typically consist of many vessels with heavy air defence armament but they are also able to launch fighter jets for combat air patrol overhead to intercept incoming airborne threats.

Question: What kind of weapons can usually be found on smaller boats and ships?

Question: These weapons can be deadly to aircraft that is low if it is linked to what?

Question: What type of ships are particularly well defended?

Question: Carrier battle groups can launch what to intercept incoming threats?
Passage: Rocket-propelled grenades can be—and often are—used against hovering helicopters (e.g., by Somali militiamen during the Battle of Mogadishu (1993)). Firing an RPG at steep angles poses a danger to the user, because the backblast from firing reflects off the ground. In Somalia, militia members sometimes welded a steel plate in the exhaust end of an RPG's tube to deflect pressure away from the shooter when shooting up at US helicopters. RPGs are used in this role only when more effective weapons are not available.

Question: What type of weapon can be used against hovering helicopters?

Question: What did some militia members in Somalia weld in the exhaust of the RPG tube to protect the shooter?

Question: What were the Somalian militia members firing RPGs at?

Question: An RPG fired at a steep angle has what reflecting off the ground?

Question: When an RPG is fired at a steep angle, who is in danger?
Passage: The British adopted "effective ceiling", meaning the altitude at which a gun could deliver a series of shells against a moving target; this could be constrained by maximum fuse running time as well as the gun's capability. By the late 1930s the British definition was "that height at which a directly approaching target at 400 mph (=643.6 km/h) can be engaged for 20 seconds before the gun reaches 70 degrees elevation". However, effective ceiling for heavy AA guns was affected by non-ballistic factors:

Question: What term is used to describe the altitude for a gun to shoot shells against a target that is moving?

Question: Who adopted the use of the term, effective ceiling?

Question: Along with other factors, how long must a target be engaged to have effective ceiling?

Question: What affected the effective ceiling for heavy AA guns?
Passage: Until the 1950s guns firing ballistic munitions were the standard weapon; guided missiles then became dominant, except at the very shortest ranges. However, the type of shell or warhead and its fuzing and, with missiles the guidance arrangement, were and are varied. Targets are not always easy to destroy; nonetheless, damaged aircraft may be forced to abort their mission and, even if they manage to return and land in friendly territory, may be out of action for days or permanently. Ignoring small arms and smaller machine-guns, ground-based air defence guns have varied in calibre from 20 mm to at least 150 mm.

Question: What was the standard weapon until the 1950s?

Question: After guns firing ballistic munitions lost their appeal, what weapon took their place?

Question: Which range did not use guided missiles?

Question: Damaged aircraft can be out of action for days or what?

Question: What is the largest calibre ground-based air defence guns?
Passage: The British recognised the need for anti-aircraft capability a few weeks before World War I broke out; on 8 July 1914, the New York Times reported that the British government had decided to 'dot the coasts of the British Isles with a series of towers, each armed with two quick-firing guns of special design,' while 'a complete circle of towers' was to be built around 'naval installations' and 'at other especially vulnerable points.' By December 1914 the Royal Naval Volunteer Reserve (RNVR) was manning AA guns and searchlights assembled from various sources at some nine ports. The Royal Garrison Artillery (RGA) was given responsibility for AA defence in the field, using motorised two-gun sections. The first were formally formed in November 1914. Initially they used QF 1-pounder "pom-pom" (a 37 mm version of the Maxim Gun).

Question: When did the British see the need to add anti-aircraft capability?

Question: Where did the New York times report say towers with guns should go?

Question: What was built around naval installations?

Question: Who manned AA guns and searchlights?

Question: Who used motorised two-gun sections?
Passage: In Britain and some other armies, the single artillery branch has been responsible for both home and overseas ground-based air defence, although there was divided responsibility with the Royal Navy for air defence of the British Isles in World War I. However, during the Second World War the RAF Regiment was formed to protect airfields everywhere, and this included light air defences. In the later decades of the Cold War this included the United States Air Force's operating bases in UK. However, all ground-based air defence was removed from Royal Air Force (RAF) jurisdiction in 2004. The British Army's Anti-Aircraft Command was disbanded in March 1955, but during the 1960s and 1970s the RAF's Fighter Command operated long-range air -defence missiles to protect key areas in the UK. During World War II the Royal Marines also provided air defence units; formally part of the mobile naval base defence organisation, they were handled as an integral part of the army-commanded ground based air defences.

Question: Who provided part of the air defence of the British Isles in WWI

Question: Who protected airfields in WWII?

Question: The United States Air Force helped protect the UK during what 'war'?

Question: What year was ground-based air defence taken from RAF?

Question: What was disbanded in 1955?
Passage: The British dealt with range measurement first, when it was realised that range was the key to producing a better fuse setting. This led to the Height/Range Finder (HRF), the first model being the Barr & Stroud UB2, a 2-metre optical coincident rangefinder mounted on a tripod. It measured the distance to the target and the elevation angle, which together gave the height of the aircraft. These were complex instruments and various other methods were also used. The HRF was soon joined by the Height/Fuse Indicator (HFI), this was marked with elevation angles and height lines overlaid with fuse length curves, using the height reported by the HRF operator, the necessary fuse length could be read off.

Question: What helped with better fuse setting?

Question: What was the first model of HRF (Height Range Finder) used by the British?

Question: The HRF measured target distance and what else?

Question: What was the HRF used with to set fuses?

Question: The fuse length could be set using height reported by whom?
Passage: By the early 20th century balloon, or airship, guns, for land and naval use were attracting attention. Various types of ammunition were proposed, high explosive, incendiary, bullet-chains, rod bullets and shrapnel. The need for some form of tracer or smoke trail was articulated. Fuzing options were also examined, both impact and time types. Mountings were generally pedestal type, but could be on field platforms. Trials were underway in most countries in Europe but only Krupp, Erhardt, Vickers Maxim, and Schneider had published any information by 1910. Krupp's designs included adaptations of their 65 mm 9-pounder, a 75 mm 12-pounder, and even a 105 mm gun. Erhardt also had a 12-pounder, while Vickers Maxim offered a 3-pounder and Schneider a 47 mm. The French balloon gun appeared in 1910, it was an 11-pounder but mounted on a vehicle, with a total uncrewed weight of 2 tons. However, since balloons were slow moving, sights were simple. But the challenges of faster moving airplanes were recognised.

Question: What kind of guns started attracting attention?

Question: In addition to ammo proposals, what other need was articulated?

Question: The impact and time types of what were analyzed?

Question: As of 1910, who had published info available for gun designs?

Question: What gun made the scene in 1910?