114 Sentences With "bombsights" | Random Sentence Generator

Bombsights used on Lancasters included:Black, Henry. "Bombsights." lancaster-archive.com, 2001. Retrieved 14 November 2010.

Then, in World War II, tachometric bombsights were often combined with radar systems to allow accurate bombing through clouds or at night. When postwar studies demonstrated that bomb accuracy was roughly equal either optically or radar-guided, optical bombsights were generally removed and the role passed to dedicated radar bombsights. Finally, especially since the 1960s, fully computerized bombsights were introduced, which combined the bombing with long-range navigation and mapping. Modern aircraft do not have a bombsight but use highly computerized systems that combine bombing, gunnery, missile fire and navigation into a single head-up display.

Sperry moved into related devices such as bombsights, fire control, radar, and automated take off and landing.

They were replaced by the earliest custom-designed systems, normally iron sights that could be set based on the aircraft's airspeed and altitude. These early systems were replaced by the vector bombsights', which added the ability to measure and adjust for winds. Vector bombsights were useful for altitudes up to about 3,000 m and speeds up to about 300 km/h. In the 1930s, mechanical computers with the performance needed to "solve" the equations of motion started to be incorporated into the new tachometric bombsights, the most famous of which is the Norden.

By the end of the war, Norden and its subcontractors had produced 72,000 M-9 bombsights for the U.S. Army Air Force alone, costing $8,800 each.

The Glasgow Army Airfield Norden Bombsight Vault was listed on the National Register of Historic Places in 2011. It is a one-story concrete shed with a projection that has -thick walls and a poured concrete floor. It protected Norden bombsights at the Glasgow Army Airfield during World War II. The bombsights were top-secret and were used on B-29 bombers. It had steel vault doors which have been removed.

The Carl Zeiss Lotfernrohr 7 (Lot meant "Vertical" and Fernrohr meant "Telescope"), or Lotfe 7, was the primary series of bombsights used in most Luftwaffe level bombers, similar to the United States' Norden bombsight, but much simpler to operate and maintain. Several models were produced and eventually completely replaced the simpler Lotfernrohr 3 and BZG 2 bombsights. The Lotfe 7C, appearing in January 1941, was the first one to have gyroscopic stabilization.

The conversion of Norden Laboratories Corporation's New York City engineering lab to a production factory was a long process. Before the war, skilled craftsmen, most of them German or Italian immigrants, hand-made almost every part of the 2,000-part machine. Between 1932 and 1938, the company produced only 121 bombsights per year. During the first year after the Attack on Pearl Harbor, Norden produced 6,900 bombsights, three-quarters of which went to the U.S. Navy.

As the effectiveness of a bomber was dependent on the weight and accuracy of its bomb load, ever larger bombers were developed starting in World War I, while considerable money was spent developing suitable bombsights.

The Norden Bombsight and Sperry Bombsight were both used onboard Army and Navy bombers during the war. Both bombsights used gyroscopes, telescopes and analog computers to calculate the release point for bombers to drop their payloads accurately onto ground targets. The A-5 had the ability to be integrated with these bombsights. Once the bombardier found the target and adjusted the bombsight, the autopilot would be engaged to fly the aircraft straight and level to the target, where the bombsight would automatically calculate the release point of the bombs.

The small force destroyed a transport ship, bombed Hong Kong's vital Kowloon Harbor and claimed 27 enemy aircraft for the loss of one bomber and one fighter. Haynes asked Bissell for more Norden bombsights—the Mitchell mediums shared only two between all the squadrons, and their supplied D-8 bombsights were ones Haynes considered to be of no value. He sent a small force of eight B-24s to bomb Mandalay on November 8 followed in two days with a repeat visit by six of the heavy bombers.

When the Korean War opened, these aircraft were pressed into service and the Norden once again became the USAF's primary bombsight. This occurred again when the Vietnam War started; in this case retired World War II technicians had to be called up in order to make the bombsights operational again. Its last use in combat was by the Naval Air Observation Squadron Sixty-Seven (VO-67), during the Vietnam War. The bombsights were used in Operation Igloo White for implanting Air-Delivered Seismic Intrusion Detectors (ADSID) along the Ho Chi Minh Trail.

Alternately, Oboe was sometimes used for attacks on point targets by single aircraft, or a small number dropping one after the other. In tests, Oboe demonstrated accuracies greater than those of optical bombsights during daylight in good weather.

In many early bombsights, the first two inputs were adjusted by separately setting the front and back sights of an iron sight, one for the altitude and the other for the speed. Terminal velocity, which extends the fall time, can be accounted for by raising the effective altitude by an amount that is based on the bomb's measured ballistics. When windage is accounted for, the calculations become more complex. As the wind can operate in any direction, bombsights generally re-calculate the windage by converting it into the portions that act along the flight path and across it.

Messerschmitt Bf 110 Bombsights Over England: Erprobungsgruppe 210 in the Battle of Britain by John Vasco However, there was no national electricity network in the UK at this time, only the local generation of electricity for each city/town and surrounding area.

An early use of fire-control systems was in bomber aircraft, with the use of computing bombsights that accepted altitude and airspeed information to predict and display the impact point of a bomb released at that time. The best known United States device was the Norden bombsight.

In order to assemble the formations to carry out these bombing campaigns, assembly ships were used to quickly form defensive combat boxes. The RAF concentrated its efforts on night bombing. But neither force was able to develop adequate bombsights or tactics to allow for often-bragged "pinpoint" accuracy.

A good example of its replacement was the refitting of the Doolittle Raiders with a simple iron sight. Designed by Capt. C. Ross Greening, the sight was mounted to the existing pilot direction indicator, allowing the bombardier to make corrections remotely, like the bombsights of an earlier era."Doolittle Raid".

Typically, the aircraft was armed with two machine guns on board: one placed in the nose to by operated by the observer and the other in the rear gunner's cockpit. Bombsights were made in Yugoslavia and the bombing of Viro in low flight also Brilet local sights.Isaić, Vladimir; Frka Danijel (2010.).

For simplicity, consider that 5% to be a 5 degree angle. Using simple trigonometry, 5 degrees at 20,000 feet is approximately 1,750 feet, an error that would place the bombs far outside their lethal radius. In tests, accuracies of 3 to 4 degrees were considered standard, and angles as high as 15 degrees were not uncommon. Given the seriousness of the problem, systems for automatic levelling of bombsights was a major area of study before World War II, especially in the US.All of the USAAC's pre-war bombsights featured some system for automatically levelling the sight; the Estopery D-series used pendulums, Sperry designs used gyroscopes to stabilize the entire sight, and the Norden used gyroscopes to stabilize the optics.

Through simple mechanical means, it performs continual integration of the value of an input. Typical uses were the measurement of area or volume of material in industrial settings, range- keeping systems on ships, and tachometric bombsights. The addition of the torque amplifier by Vannevar Bush led to the differential analysers of the 1930s and 1940s.

Rapid production lines established a rate of overhaul on accessories, bombsights, guns, and electrical equipment that set records for both military and commercial repair agencies. By 1944, Kelly's workforce had grown tremendously. In 1939, old Duncan Field had 1,100 civilian employees and only 10 military personnel. By 1945, over 15,000 civilians and 16,000 military worked at Kelly.

Incendiary bombs created massive damage in many cities due to fires started by the thermite. Cities that primarily consisted of wooden buildings were especially susceptible. These incendiary bombs were utilized primarily during nighttime air raids. Bombsights could not be used at night, creating the need to use munitions that could destroy targets without the need for precision placement.

An He 177 in a shallow dive. The He 177 was meant to have dive-bombing capabilities. The inaccuracy of horizontal bombing during the Ural bomber program demonstrated weaknesses in German bombsights and created doubts about the effectiveness of level bombing of factories. While Wever had been advocating the Ural Bomber concept, others in the Luftwaffe were growing increasingly interested in dive bombing.

On the night of 30 January 1943, thirteen Stirlings and Halifaxs of the "Pathfinder" force used H2S to drop incendiaries or flares on a target in Hamburg. One hundred Lancasters following the Pathfinders used the flares as the target for their bombsights. Seven of the Pathfinders had to turn back, but six marked the target, and the results were considered "satisfactory".

This allowed the autopilot to detect the velocity and acceleration of the change. The calculated change was then communicated quickly to the control surfaces by independent electro-hydraulic servos. This led to faster, more stable corrections of the aircraft. The faster stabilization of the aircraft by the A-5 autopilot made it possible for new bombsights to be used on military aircraft.

The original V1 became a transport in 1938. The Dornier Do 19 had a disappointing performance: it was slow, carried only a 1,600 kg bombload, and had only medium range. In fact, the whole Ural bomber concept had already been abandoned, not only because the required range was impossible, but also because existing navigation and bombsights were not up to the task.

Cameras were also fitted to the aircraft so the bombs' trajectory and effect could be recorded. Testing of the Disney bombs began in early 1945. Bombs were initially dropped on a bombing range near Southampton to photographically record their trajectory and calibrate bombsights. This was necessary as the flight-path of a rocket-accelerated bomb differed considerably from that of a free–falling bomb.

CENCO dominated the field of selling science education equipment through their mail order catalog. By 1935, the company established itself as one of the leading national suppliers of science equipment. During World War II, part of the manufacturing facility was turned over to the production of war necessities, making bombsights for airplanes and fuses for large bombs. After 1968, the company began having financial difficulties.

Boyle 1962:p. 163 In December 1915, Haig replaced Sir John French as Commander of the British Expeditionary Force and the Haig-Trenchard partnership resumed, this time at a higher level.Lyall 1976:p. 179 During the early stages of the Battle of Verdun in 1916, Trenchard supplied Lewis guns, bullets and bombsights to the French Air Service which was under the command of Paul-Fernaud du Peuty.

This sight combined the images of the radar and a lens system in front of the aircraft, allowing them to be directly compared at once through a binocular eyepiece.Y-4 Horizontal Periscopic Bombsight. National Museum of the United States Air Force. 2 June 2015 Bombsights on older aircraft, like the Boeing B-29 Superfortress and the later B-50, were left in their wartime state.

Another advantage, perhaps more important, was that the measurement was made simply by aligning a sight on an object on the ground through a small telescope or reflector sight. All of the complicated calculations and setup of the vector designs were eliminated and the chance of user error along with it. These tachometric or synchronous bombsights were an area of considerable research during the 1930s.

The Mk. X had to be abandoned, and Mk. VII's and Mk. IX's hurriedly re-fit to aircraft. Thus the older versions of the CSBS soldiered on long after they were due to be replaced, and remained the primary British bombsights into 1942. The Mk. VII was widely found on slower aircraft and training schools, while the Mk. IX was used in higher speed aircraft.

The Norden then equipped almost all US high-level bombers, most notably the B-17 Flying Fortress. In tests, these bombsights were able to generate fantastic accuracy. In practice, however, operational factors seriously upset them, to the point that pinpoint bombing using the Norden was eventually abandoned.Geoffery Perrett, "There's a War to Be Won: The United States Army in World War II", Random House, 1991, p.

Crewed by four or five, the BR.20's two pilots sat side by side with the engineer/radio operator/gunner behind. The radio operator's equipment included a R.A. 350-I radio-transmitter, A.R.5 receiver and P.3N radio compass.Green and Swanborough 1982, p. 292. The navigator/bomb-aimer sat at a station located within the nose; this position was equipped with both bombsights and a vertical camera.

A US version of the CSBS was used by Billy Mitchell on his famous attack on the Ostfriesland in 1921. The basic design was adapted by almost all air forces and used well into World War II. It was eventually replaced in British service by more advanced designs like the Mark XIV bomb sight and the Stabilized Automatic Bomb Sight. Other services used vector bombsights throughout the war.

Over 1,400 companies produced everything from field rations to parachutes to torpedoes, while new aircraft plants employed 100,000 in the construction of engines, aluminum sheeting, bombsights, and other components. The Great Migration, which had been on pause due to the Depression, resumed at an even faster pace as the 1910 - 1930 period, as hundreds of thousands of black Americans arrived in the city to work in the steel mills, railroads, and shipping yards.

38 Norden bombsights were removed from unit B-24s and a modified gunsight, optimized for low level attacks, replaced them. Liberators that had been modified for night operations were sent to another unit and bomb bay tanks were installed in others.Freeman, pp. 86–89 B-24 on target in Operation Tidal Wave In June, the air echelon returned to Libya and initially supported Operation Husky, the invasion of Sicily, flying ten missions.

The introduction of Strike Wings led to some use of the Mk. III, as well as older bombsights. Late in the war, Bomber Command passed off its obsolete Handley Page Halifax bombers to Coastal Command, who re-equipped them with the Mk. III and used them in long-range strikes against German ships in the Skagerrak and Kattegat. The Mk. XIV was ultimately never used by Coastal Command in the anti-shipping role.

In the postwar era, the development of new precision bombsights essentially ended. At first this was due to the military drawdown, but as budgets increased again during the opening of the Cold War, the bomber mission had passed to nuclear weapons. These required accuracies on the order of , well within the capabilities of existing radar bombing systems. Only one major bombsight of note was developed, the Y-4 developed on the Boeing B-47 Stratojet.

Initial probes in this direction were also rebuffed. When a report stated that the Norden's results were three to four times as good as their own bombsights, the Air Ministry decided to sweeten the pot and suggested they offer information on radar in exchange. This too was rebuffed. The matter eventually worked its way to the Prime Minister, Neville Chamberlain, who wrote personally to President Roosevelt asking for the Norden, but even this was rejected.

In January 1942 Russ Baker rescued the crews of three B-26 bombers that had made an emergency landing between Fort Nelson, British Columbia and Watson Lake, Yukon where there was a refueling station. The mishap occurred the 16th of January, and Russ eventually located the planes and crews. To an improvised runway he flew a dozen missions over several days to extract 24 crewmen and two officers. The Norden bombsights were recovered from the downed aircraft.

The squadron also detached Mitchells to act as navigation ships for Douglas A-20 Havocs of the 312th Bombardment Group attacking targets in southwestern New Guinea. The A-20s were not equipped with bombsights and could only make medium altitude attacks by "dropping on leader" (releasing their bombload at the same time as the lead aircraft, equipped with a bombsight, in a formation). Squadron aircraft also dropped food and supplies to isolated parties in the interior of the island.

Some German crews had been trained in new bombing techniques. A small number of bomb-aimers were to use their Lotfernrohr 7 bombsights on individual flares to increase the accuracy of the attack. The attack followed the typical pattern; a northerly course, and a turn to the south east at High Wycombe across London and out across the eastern Channel. Pilots were ordered to reach the coast at 16,000 ft and descend to 13,000 ft over the target.

The second station was used, as in Y-Gerät, to time the bomb drop. Unlike Y-Gerät, Oboe was deliberately built to offer very high accuracy, as good as 35 m, much better than even the best optical bombsights. One problem with Oboe was that it allowed only one aircraft to be guided at a time. This was addressed in the later Gee-H system by placing the transponder on the ground and broadcaster in the aircraft.

The Norden saw reduced use in the post-World War II period after radar-based targeting was introduced, but the need for accurate daytime attacks kept it in service, especially during the Korean War. The last combat use of the Norden was in the U.S. Navy's VO-67 squadron, which used them to drop sensors onto the Ho Chi Minh Trail as late as 1967. The Norden remains one of the best- known bombsights ever invented.

The trail adjustment, set by dialling in the measured terminal velocity for the bombs being dropped, used a cam to move the height bar forward away from the vertical, reducing the range angle and thereby reducing the range to account for this effect. Many thousands of CSBSs were sold around the world, and many other sights were developed from the basic idea. In the mid-1930s, the basic CSBS concept was largely universal for production bombsights.

It was not until January 1942 that it was given priority. This was aided by Sperry Gyroscope, who re-designed the system to U.S. production methods. They sub-contracted construction to A.C. Spark Plug who built tens of thousands as the Sperry T-1. It did not offer the level of accuracy of tachometric bombsights like the Norden or ABS, but for night area bombing from medium altitude as practiced by RAF Bomber Command this was not an issue.

The bomb aimer then watched the target in the sight until it crossed the pointer, and dropped the bombs. Similar bombsights were developed in France and England, notably the Michelin and Central Flying School Number Seven bombsight. While useful, these sights required a time-consuming setup period while the movement was timed. A great upgrade to the basic concept was introduced by Harry Wimperis, better known for his later role in the development of radar in England.

Some 5,000 men underwent a complex training process that prepared them to rebuild the vessels and operate them once on the water. By the end of the year, the vessels departed Mobile. One of the keys to Allied victory in Europe was the Norden Bomb Sight, which enabled bomber squadrons to target Germany's war-making industry and infrastructure much more accurately. The military repaired and calibrated the bombsights at Brookley in a secret facility, still standing and in use today.

As the technique required the aircraft to fly at very low altitudes directly at the ship, it made shooting down the aircraft easier as well. In the immediate pre-war era, there was considerable effort to develop new bombsights that would allow the aircraft to remain at higher altitudes. The most notable was the US Navy's Norden bombsight, which was fit to most Navy aircraft. In practice, these proved largely useless, and the skip-bombing technique was soon introduced operationally.

Production quickly followed, and by 1918 about 720 had been produced. The Royal Flying Corps (RFC) started using the Mark I sight as soon as supplies were available, and by April 1918 were also fully converted to this type. For his work on the CSBS and the Drift Sight Wimperis was awarded £2,100 by the Royal Commission on Awards to Inventors. In the post-war era, work on new bombsights was seriously curtailed, and little new development had taken place by 1930.

Born to American Civil War veteran William Hoffman and his wife Mary E Aearn on 17 December 1884 at Fort Slocum, Davids Island, New Rochelle, New York. Edward L. Hoffman after enlisting in the infantry 21 July 1909, commissioned as an officer on 9 October 1911. In 1917 he transferred to the Aviation Section, Signal Corps with assignment as Engineering Division Chief at McCook Field. As Chief, Hoffman's division worked on all aspects of aviation including parachutes, bombsights, and aerial refueling.

Torrey p. 72 Vector bombsights remained the standard by most forces well into the Second World War, and was the main sight in British service until 1942.Sir Arthur Travers Harris, "Despatch on war operations, 23rd February, 1942, to 8th May, 1945", Routledge, 1995. See Appendix C, Section VII This was in spite of the introduction of newer sighting systems with great advantages over the CSBS, and even newer versions of the CSBS that failed to be used for a variety of reasons.

In early testing in September 1941, an aircraft flying along the arc from Dover demonstrated an accuracy of , better than any bombing method then in use. Accuracy with bombs was not quite as good, as the bombs themselves were not identical and had slightly different trajectories. In a demonstration for senior officials on 2 July 1942, the system demonstrated a real-world accuracy of . In contrast, even using advanced visual bombsights like the Norden, average accuracies in 1942 were on the order of .

That has led to a series of increasingly sophisticated bombsight designs, dedicated to high- altitude level bombing. Bombsights were first used before World War I, and have since gone through several major revisions. The earliest systems were iron sights, which were pre-set to an estimated fall angle. In some cases, they consisted of nothing more than a series of nails hammered into a convenient spar, lines drawn on the aircraft, or visual alignments of certain parts of the structure.

In practice, it was generally simpler to have the aircraft fly in such a way to zero out any sideways motion before the drop, and thereby eliminate this factor. This is normally accomplished using a common flying techniques known as crabbing or sideslip. Bombsights are sighting devices that are pointed in a particular direction, or aimed. Although the solution outlined above returns a point in space, simple trigonometry can be used to convert this point into an angle relative to the ground.

79 After each completed mission, bomber crews left the aircraft with a bag which they deposited in a safe ("the Bomb Vault"). This secure facility ("the AFCE and Bombsight Shop") was typically in one of the base's Nissen hut (Quonset hut) support buildings. The Bombsight Shop was manned by enlisted men who were members of a Supply Depot Service Group ("Sub Depot") attached to each USAAF bombardment group. These shops not only guarded the bombsights but performed critical maintenance on the Norden and related control equipment.

Grumman was also prominent in the US space program, being the producer of the Apollo Lunar Excursion Module. In their early decades, aerospace-related companies were concentrated on Long Island, especially in eastern Nassau County in the Bethpage area. Over the years, the industry also diversified to other locations. The Sperry Gyroscope company did very well during WW-II as military demand skyrocketed; it specialized in high technology devices such as gyrocompasses, analog computer-controlled bombsights, airborne radar systems, and automated take-off and landing systems.

The development and operation of naval fire-control systems is extensively covered throughout Friedman and Baker, 2008. This system of progressive estimation is easily adapted to the bombsight role. In this case, the unknown measurement is not the target's speed or heading, but the bomber's movement due to the wind. To measure this, the bomb aimer first dials in estimates of the wind speed and direction, which causes the computer to begin moving the bombsights to stay pointed at the target as the bomber moved toward it.

The US Navy began a bombsight development program with Carl Norden during the 1920s, initially focused on a gyroscopically stabilized sight of otherwise unadvanced design. The Navy had found that bombsights were almost always used with the sights not properly leveled with respect to the ground, so any angles measured through the sight were wrong. An error of only a few degrees represents an error of hundreds of feet when bombing from high altitudes. Stabilization, which automatically levels the sight, was found to roughly double overall accuracy.

Unfortunately, the ABS was even larger than the CSBS, and the demands for new bombsights to be stabilized would make it even larger and meant it would take some time before it could be brought into service. Something was needed in the meantime. The physicist and scientific advisor Patrick Blackett took up the challenge of fixing all of these problems at once, producing the Blackett sight with the Royal Aircraft Establishment. First, the manual calculator was replaced by an external box operated by a new crew member.

At the time of Dahlgren's establishment, the area was extremely remote and relatively unpopulated. Thus, to recruit and retain the highly specialized work force required, the Navy promised to supply housing, food and medical services, schools, recreation, and other socially needed infrastructure. In the 1920s and 1930s, Dahlgren was involved in testing bombsights, including the Norden bombsight, for the Navy's fledgling air forces. But, until World War II, much of the principal work at Dahlgren surrounded the proofing and testing of every major gun in the Navy's arsenal.

RAF Wing Commander Willie Tait (at left) and an Australian officer standing on the wreck of Tirpitz in late 1945 The British military undertook several analyses of the attack. In December 1944, No. 5 Group's headquarters investigated the accuracy of the bombing. This analysis found that No. 617 Squadron had been much more accurate than No. 9 Squadron, possibly due to the latter squadron's bombardiers inputting an inaccurate wind speed into their bombsights. The superior Stabilized Automatic Bomb Sight fitted to No. 617 Squadron's aircraft may have also contributed to the difference.

Winds at typical bombing altitudes tend to be fairly strong, and it was not uncommon for there to be a wind. Compared to the aircraft's typical speed, this represents 20% of the overall velocity of the aircraft when it drops its bombs. Measuring this wind is accomplished by looking through the bombsight at objects on the ground, and then calculating the angle needed to fly to offset this motion. High-level bombsights generally spent a considerable amount of their design complexity on trying to account for the effect of wind.

To improve the calculation time, the Norden used a mechanical computer inside the bombsight to calculate the range angle of the bombs. By simply dialing in the aircraft's altitude and heading, along with estimates of the wind speed and direction (in relation to the aircraft), the computer would automatically, and quickly, calculate the aim point. This not only reduced the time needed for the bombsight setup but also dramatically reduced the chance for errors. This attack on the accuracy problem was by no means unique; several other bombsights of the era used similar calculators.

It was the way the Norden used these calculations that differed. Conventional bombsights are set up pointing at a fixed angle, the range angle, which accounts for the various effects on the trajectory of the bomb. To the operator looking through the sights, the crosshairs indicate the location on the ground the bombs would impact if released at that instant. As the aircraft moves forward, the target approaches the crosshairs from the front, moving rearward, and the bombardier releases the bombs as the target passes through the line of the sights.

It was an early tachometric design that directly measured the aircraft's ground speed and direction, which older bombsights could only estimate with lengthy manual procedures. The Norden further improved on older designs by using an analog computer that continuously recalculated the bomb's impact point based on changing flight conditions, and an autopilot that reacted quickly and accurately to changes in the wind or other effects. Together, these features promised unprecedented accuracy for daytime bombing from high altitudes. During prewar testing the Norden demonstrated a circular error probable (CEP) of , an astonishing performance for that period.

Typical bombsights of the pre-war era worked on the "vector bombsight" principle introduced with the World War I Course Setting Bomb Sight. These systems consisted of a slide rule-type calculator that was used to calculate the effects of the wind on the bomber based on simple vector arithmetic. The mathematical principles are identical to those on the E6B calculator used to this day. In operation, the bombardier would first take a measurement of the wind speed using one of a variety of methods, and then dial that speed and direction into the bombsight.

As the sight was not stabilized, any manoeuvres to correct for misalignment interfered with the ability to measure the heading, so these corrections further extended the bomb run. The CSBS generally required the bomber to fly straight and level for a lengthy time. Although the need for an improved CSBS was known in the 1930s, little work on developing such a sight was carried out. That was because an entirely new class of tachometric bombsights were being developed, which offered dramatically improved accuracy and automated much of the setup.

A great debate broke out in the RAF about the relative merits of the two bombsights; although the SABS was more accurate, the Mk. XIV was generally easier to use and offered greater tactical flexibility. In the end the point was moot, as the war ended before Tiger Force was deployed. Those Lincolns that were equipped with SABS, including those of 9 and 44 Squadron, continued use in the post-war era. The SABS were not used after the Lincolns were withdrawn from service, replaced by the English Electric Canberra jet bomber and other types.

The Encyclopedia of Military Aircraft, 2006 Edition, Jackson, Robert Parragon Publishing 2002 Variations on the design were common, like the US Estoppey bombsight. All of these bombsights shared the problem that they were unable to deal with wind in any direction other than along the path of travel. That made them effectively useless against moving targets, like submarines and ships. Unless the target just happened to be travelling directly in line with the wind, their motion would carry the bomber away from the wind line as they approached.

Versions for different speeds, altitudes and bomb types were introduced as the war progressed. After the war, the CSBS continued to be the main bombsight in British use. Thousands were sold to foreign air forces and numerous versions were created for production around the world. A number of experimental devices based on a variation of the CSBS were also developed, notably the US's Estoppey D-1 sight,"Interwar Development of Bombsights" , US Air Force Museum, 19 June 2006 developed shortly after the war, and similar versions from many other nations.

With the exception of operational considerations – limited resolution of the radar and limited range of the navigation systems – the need for visual bombsights quickly disappeared. Designs of the late-war era, like the Boeing B-47 Stratojet and English Electric Canberra retained their optical systems, but these were often considered secondary to the radar and radio systems. In the case of the Canberra, the optical system only existed due to delays in the radar system becoming available."Biographical memoirs of fellows of the Royal Society", Royal Society, Volume 52, p.

50 U-37 reported the convoy to Bordeaux- Mérignac Air Base and commenced shadowing the convoy providing beacon signals for Kampfgeschwader 40. Five Focke-Wulf Fw 200 Condor bombers took off at dawn and found the convoy at noon southwest of Lisbon. The Fw 200s bombed from an altitude of because they lacked bombsights. Each flight mechanic fired at their target ship with a ventral machine gun during the approach to discourage anti-aircraft gunners; but one of the bombers was hit in a wing fuel tank and crash-landed in Spain when fuel was exhausted on the return trip.

The Lotfernrohr 7 bombsights, which became the standard bombsight for German bombers, were also fitted to the P-2. The P-2 was also given "field equipment sets" to upgrade the weak defensive armament to four or five MG 15 machine guns. The P-2 had its bomb capacity raised to 4 ESA-250/IX vertical magazines. The P-2 thus had an empty weight of 6,202 kg (13,272 lb), a loaded weight increased to 12,570 kg (27,712 lb) and a maximum range of 2,100 km (1,305 mi). The P-3 was powered with the same DB601A-1 engines.

Despite the "lite" tag, a fair amount of realism has been built in; 60s-style bombsights are simulated for the pre 1970's aircraft rather than modern computer-aided aiming reticules. Dive bombing and level bombing techniques have to be worked out by the game player if they are to have success at completing missions. Aircraft that come into service after 1970 have advanced Head-Up-Displays that allow the player to aim bombs with more accuracy than manual dive bombing techniques. The A and B versions of the AGM-65 Maverick, allowing much easier ground target destruction for the late 1970s aircraft.

The aircraft had crude bombsights and carried six to ten bombs that had been converted from shells, and were released through metal tubes on each side of the cockpit. On 5 September, during the first successful operation, two Farman seaplanes dropped several bombs on the Bismarck battery, the main German fortifications in Tsingtao. The bombs landed harmlessly in the mud, but the aircraft were able to confirm that was not at Tsingtao, this was intelligence of major importance to Allied naval command. On 30 September Wakamiya was damaged by a mine and later sent back to Japan for repairs.

Many of its workers were exempted from the draft during World War II since they were doing vital defense work, including making Norden bombsights and even some work on the atomic bomb. By the early 1960s, the mill town had a movie theatre, an AM radio station (WESO), and an airport. New immigrants from Puerto Rico, Laos, and Vietnam began arriving in the 1970s and 1980s, and the town now has a significant Hispanic and Puerto Rican population. The American Optical Company shut down in 1984, and Southbridge is still struggling from the loss of these and other manufacturing jobs.

Chapter 16 Through January 1945, it bombed airfields and installations on New Guinea, Celebes, and Halmahera, and flew reconnaissance missions. The group also detached Mitchells to act as navigation ships for Douglas A-20 Havocs of the 312th Bombardment Group attacking targets in southwestern New Guinea. The A-20s were not equipped with bombsights and could only make medium altitude attacks by "dropping on leader" (flying in formation and releasing their bombload at the same time as the lead aircraft, equipped with a bombsight). Group aircraft also dropped food and supplies to isolated parties in the interior of the island.

Advanced training in bombardment and observation, like that in pursuit, entailed work in classrooms and hangars as well as in the air. Students flew DH-4s and were schooled in flying, bombsights, camera obscura, gunnery, and, among other things, the history of the development of aviation. At the Observation School, students transitioned to and learned DH-4 airplanes. There were courses on formation and cross-country flying; visual and photographic reconnaissance; surveillance; intelligence; liaison with ground forces; observation and adjustment of artillery fire; map reading; meteorology; maintenance and operation of radio, telephone, and telegraph; Liberty engines; and rigging.

Prior to the introduction of the CSBS, bombsights were generally very simple systems of limited accuracy suitable only for low-level use. The primary pre-war device in RNAS service was the Lever Sight, which the pilot had to hold out of the cockpit in one hand while flying the aircraft with the other. The Central Flying School Sight replaced this in 1915, but was difficult to install in the cockpit. The CFS was in turn replaced by the Equal Distance Sight (EDS) designed in 1916 by F. W. Scarff, better known for the development of the Scarff ring.

An early bombsight, 1910s 1923 Norden MK XI Bombsight Prototype A bombsight is a device used by military aircraft to drop bombs accurately. Bombsights, a feature of combat aircraft since World War I, were first found on purpose- designed bomber aircraft and then moved to fighter-bombers and modern tactical aircraft as those aircraft took up the brunt of the bombing role. A bombsight has to estimate the path the bomb will take after release from the aircraft. The two primary forces during its fall are gravity and air drag, which make the path of the bomb through the air roughly parabolic.

Bombardiers were required to crawl down shafts that gave way to the "bubble," from which they had bird's-eye views of the ground below. The bombardier's job was to feed the bombsight the needed information, air speed, wind speed, wind direction, altitude, and the angle of drift. As the aircraft approached the target, the pilot turned the aircraft over to the bombardier and the Norden bombsight, which was also an automatic pilot that flew the aircraft as bombs were released over the target. Classroom instruction at the Albuquerque base was held at night and training missions were flown during the day to bombsights around Albuquerque.

The squadron was awarded its first Distinguished Unit Citation (DUC) for this action. This award to group headquarters and three of the 44th's squadrons, was the first made to an Eighth Air Force bomber unit. 44th Group Liberator on Operation Tidal Wave In late June 1943, a large detachment of the squadron moved to Soluch Airfield, Libya, ostensibly to assist in Operation Husky, the invasion of Sicily, by attacking airfields and marshalling yards in Italy. However, prior to deploying to Africa, the squadron had engaged in extensive low level training in England, and the Norden bombsights in its planes had been replaced by a simpler sight.

The ships were used on an eastbound route from Bordeaux to Singapore (then in Japanese, thus Axis, hands) with cargoes of mercury, steel and aluminum bars, welding steel, bomb prototypes, 20 mm guns, blueprints for tanks and bombsights, and up to a dozen passengers. Return trip loadings were 110-155 tons of rubber, 44-70 tons of zinc, five tons of tungsten, two tons of quinine, two tons of opium, bamboo, rattan, and passengers. Comandante Cappellini, Reginaldo Giuliani, and Enrico Tazzoli departed Bordeaux in May 1943. The first two completed their voyages in July and August, but Enrico Tazzoli was destroyed by Allied bombers in the Bay of Biscay.

The pilot would follow the PDI as before. To time the drop, Norden used an idea already in use on other bombsights, the "equal distance" concept. This was based on the observation that the time needed to travel a certain distance over the ground would remain relatively constant during the bomb run, as the wind would not be expected to change dramatically over a short period of time. If you could accurately mark out a distance on the ground, or in practice, an angle in the sky, timing the passage over that distance would give you all the information needed to time the drop.

Despite the "Lite" tag, a fair amount of realism has been built in; 1960s-style bombsights are simulated rather than modern computer-aided aiming reticules. Dive bombing and level bombing techniques have to be worked out by the game player if they are to have success at completing missions. US Air to Air missiles in the game consist of early versions of the AIM-9 Sidewinder, AIM-7 Sparrow, and AIM-4 Falcon which are simulated to be as unreliable as the real missiles were. So regardless of having a "good lock on the target" there is a good chance the missile will miss.

The opening of World War II led to significant expansion as the company produces optics for range finders, bombsights, and reconnaissance systems. This work led to the US Navy awarding them the first "E" for Excellence award in 1942. Perkin-Elmer retained a strong presence in the military field through the 1960s and became a primary supplier of the optical systems used in many reconnaissance platforms, first in aircraft and high-altitude balloons, and then in reconnaissance satellites. A significant advance was 1955's Transverse Panoramic Camera, which took images on wide frames that provided single-frame images from horizon to horizon from an aircraft flying at 40,000 ft altitude.

There was some interest in this sight after World War I but reflector sights in general were not widely adopted for fighter and bomber aircraft until the 1930s, first by the French, then by most other major airforces. These sights were not only used for aiming fighter aircraft, they were used with aircraft defensive guns and in bombsights. Reflector sights as aircraft gun-sights have many advantages. The pilot/gunner need not position their head to align the sight line precisely as they did in two-point mechanical sights, head position is only limited to that determined by the optics in the collimator, mostly by the diameter of the collimator lens.

"Visual Flight Planning and Procedure" Compounding this inaccuracy is that it is made using the instrument's airspeed indication, and as the airspeed in this example is about 10 times that of the wind speed, its 5% error can lead to great inaccuracies in wind speed calculations. Eliminating this error through the direct measurement of ground speed (instead of calculating it) was a major advance in the tachometric bombsights of the 1930s and 40s. Finally, consider errors of the same 5% in the equipment itself, that is, an error of 5% in the setting of the range angle, or a similar 5% error in the levelling of the aircraft or bombsight.

One of the main problems using vector bombsights was the long straight run needed before dropping the bombs. This was needed so the pilot would have enough time to accurately account for the effects of wind, and get the proper flight angle set up with some level of accuracy. If anything changed during the bomb run, especially if the aircraft had to maneuver in order to avoid defences, everything had to be set up again. Additionally, the introduction of monoplane bombers made the adjustment of the angles more difficult, because they were not able to slip-turn as easily as their earlier biplane counterparts.

Most bombsights until this time required that the plane maintain a constant attitude (usually level), though dive-bombing sights were also common. The LABS system was originally designed to facilitate a tactic called toss bombing, to allow the aircraft to remain out of range of a weapon's blast radius. The principle of calculating the release point, however, was eventually integrated into the fire control computers of later bombers and strike aircraft, allowing level, dive and toss bombing. In addition, as the fire control computer became integrated with ordnance systems, the computer can take the flight characteristics of the weapon to be launched into account.

This captured USAAF Boeing B-17D, in Japanese livery, was flown to Japan for technical evaluation Three damaged B-17s, one "D" model and two "E" models, were rebuilt to flying status by Japanese technicians and mechanics with parts stripped from B-17 wrecks in both the Philippines and Indonesia. The three bombers, containing captured top secret Norden bombsights, were then flown to Japan where they underwent extensive technical evaluation by the Imperial Japanese Army Air Force's Air Technical Research Laboratory (Koku Gijutsu Kenkyujo) at Tachikawa. The "D" model was later deemed an obsolescent design. The two "E" models were used to develop B-17 air combat counter- tactics and also as enemy aircraft in several Japanese propaganda films.

America's entry into World War II brought a dramatic increase in demand for all types of engineering and construction, and Stone & Webster became intensely involved in the war effort. According to former Stone & Webster president Allen, "Few elements of war production were not impacted in a significant way by Stone & Webster." Typical Stone & Webster wartime assignments included the design and construction of cartridge case plants, a complete steel foundry, a plant to produce bombsights and other equipment, a plant furnishing fire-control instruments, a facility producing aircraft superchargers, and three TNT-production plants, in addition to meeting demands for infrastructure and power facilities. The company was also called upon to engage in more creative projects.

The aim point was fed back to the sight, which automatically rotated the telescope to the correct angle to account for drift and aircraft movement, keeping the target still in the view. When the bomb aimer sighted through the telescope, he could see any residual drift and relay this to the pilot, or later, feed that information directly into the autopilot. Simply moving the telescope to keep the target in view had the side effect of fine-tuning the windage calculations continuously, and thereby greatly increasing their accuracy. For a variety of reasons, the Army dropped their interest in the Sperry, and features from the Sperry and Norden bombsights were folded into new models of the Norden.

The strategic bombing role was following an evolution over time to ever-higher, ever-faster, ever-longer-ranged missions with ever- more-powerful weapons. Although the tachometric bombsights provided most of the features needed for accurate bombing, they were complex, slow, and limited to straight-line and level attacks. In 1946 the US Army Air Force asked the Army Air Forces Scientific Advisory Group to study the problem of bombing from jet aircraft that would soon be entering service. They concluded that at speeds over 1,000 knots, optical systems would be useless – the visual range to the target would be less than the range of a bomb being dropped at high altitudes and speeds.

Boy from Chicago, 1941 When general prosperity returned in 1940, Chicago had an entrenched Democratic machine, a fully solvent city government, and a population that had enthusiastically shared mass culture and mass movements. Over one-third of the workers in Chicago's manufacturing sector were unionized. During World War II, the city of Chicago alone produced more steel than the United Kingdom every year from 1939 - 1945, and more than Nazi Germany from 1943 - 1945. The city's diversified industrial base made it second only to Detroit in the value—$24 billion—of war goods produced. Over 1,400 companies produced everything from field rations to parachutes to torpedoes, while new aircraft plants employed 100,000 in the construction of engines, aluminum sheeting, bombsights, and other components.

Factory building, Brooklyn The Sperry Horizon, Sperry Gyroscope Co. Brooklyn N.Y. M2 gun director 1932 in production Coverall for female war workers Sperry Corporation (1910−1986) was a major American equipment and electronics company whose existence spanned more than seven decades of the 20th century. Through a series of mergers it exists today as a part of Unisys, while some other of its former divisions became part of Honeywell, Lockheed Martin, Raytheon Technologies, and Northrop Grumman. The company is best known as the developer of the artificial horizon and a wide variety of other gyroscope-based aviation instruments like autopilots, bombsights, analog ballistics computers and gyro gunsights. In the post-WWII era they branched out into electronics, both aviation related, and later, computers.

Somewhat desperate were Banquet Alert which called for the employment of Fleet Air Arm training aircraft under Coastal Command and Banquet Training which called for the absorption of aircraft from RAF Training Command into the operational striking force of Bomber Command. Aircraft allocated under Banquet would, in many cases, lack bombsights, armour protection, guns and self-sealing fuel tanks. While these were to be fitted where possible, RAF instructions made it clear that no aircraft was to be considered unfit for want of such niceties; anything that could fly and drop bombs would suffice. Early in July, about 1,000 aircraft, from Tiger Moths to Wellington bombers, at training schools, were ready for anti-invasion operations, with hope of another 1,000 aircraft when the scheme was complete.

During the day the bomber could use its bombsights to attack point targets, but only at the risk of being attacked by enemy fighters and anti-aircraft artillery. During the early 1930s the debate had been won by the night-bombing supporters, and the RAF and Luftwaffe started construction of large fleets of aircraft dedicated to the night mission. As "the bomber will always get through", these forces were strategic in nature, largely a deterrent to the other force's own bombers. However, new engines introduced in the mid-1930s led to much larger bombers that were able to carry greatly improved defensive suites, while their higher operational altitudes and speeds would render them less vulnerable to the defences on the ground.

In the case of Oboe, these calculations were carried out before the mission at the ground bases. But as daylight visual bombing was still widely used, conversions and adaptations were quickly made to repeat the radar signal in the existing bombsights, allowing the bombsight calculator to solve the radar bombing problem. For instance, the AN/APA-47 was used to combine the output from the AN/APQ-7 with the Norden, allowing the bomb aimer to easily check both images to compare the aim point. Analysis of the results of bombing attacks carried out using radio navigation or radar techniques demonstrated accuracy was essentially equal for the two systems – night time attacks with Oboe were able to hit targets that the Norden could not during the day.

Early strategic bombing attempts led to the development of specialized bomber aircraft, during World War I. Initially bombs were dropped by hand and aimed by the naked eye, but by the end of the war bombsights had been developed. The introduction of air raid warnings and shelters can be dated to World War I, as can the design of anti-aircraft artillery and the development of methods for coordinated aerial defence. Many of the advocates of strategic bombing during the interwar period, such as Italy's Giulio Douhet, America's Billy Mitchell, and Britain's Hugh Trenchard, had commanded aircraft during World War I. The improvements in aircraft technology during and after the war convinced many that "the bomber will always get through", and this belief influenced planning for strategic bombing during World War II.

A problem with early bombsights was that they could only correct for the effects of the wind in a simple way and required the bomber to fly directly up- or down-wind from the target, to minimise the complexity of the required calculations. This made it difficult to attack moving targets and allowed anti-aircraft artillery to sight their weapons along the wind line. In 1917 Harry Wimperis introduced the Course Setting Bomb Sight (CSBS), which replaced the tables and timings used in earlier sights with a simple mechanical calculator capable of solving the sideways drift due to the wind. As the bomb aimer turned a wind direction knob, the main portion of the sight was pushed to the left or right, indicating the required angle to fly to take the aircraft over the target.

For instance, a wind on the nose will reduce the ground speed of the aircraft, and cause bombs to fall short of the target. Some early bombsights had adjustments that could account for wind directly on the nose or tail, but this seriously hampered operational use. Not only did it make attacks on moving targets like ships almost impossible unless they just happened to be moving in the same direction as the wind, it also allowed the anti-aircraft gunners to pre-sight their weapons along the wind line, knowing that aircraft would be flying that direction. Using vector algebra to solve for the effect of wind is a common problem in air navigation, and its calculation was semi-automated in the Course Setting Bomb Sight of late World War I vintage.

In early operations, RAF Bomber Command concluded that their existing bombsights, updated versions of the World War I-era CSBS's, were hopelessly outdated in modern combat. During low-level attacks, the bombers had only moments to spot the target and then manoeuvre for an attack, and often had to dodge fire all the while. When the bomber was turning, the bombsight, fixed to the frame of the aircraft, pointed out to the sides and could not be used to adjust the approach. On 22 December 1939, at a pre-arranged meeting on bombsight policy, Air Chief Marshal Sir Edgar Ludlow- Hewitt stated flatly that the CSBS did not meet RAF requirements and asked for a bombsight that would allow the bomber to take any sort of evasive action throughout the bomb run.

Arthur "Bomber" Harris's strategy for the RAF Bomber Command was to attack area targets that the bombers could be more certain of hitting at night, while the U.S. preferred daylight, precision bombing techniques."The Bomber War" by Robin Neillands, , p.23 The development since the 1930s of gyroscope- stabilised optical bombsights, such as the Norden bombsight, also helped the Allied air forces' ability to accurately strike their targets with medium- to high-altitude level bombing attacks. Nazi Germany used high level bombers such as the Heinkel He 111, the Dornier Do 17 and multi-role aircraft such as the Junkers Ju 88 against the Allies in the Battle of Britain,"The Bomber War" by Robin Neillands, , Chapter 2 both for carpet bombing and for precision attacks on British radar stations as part of Operation Eagle.

At the same time, the ever-increasing power levels of new jet engines led to fighter aircraft with bomb loads similar to heavy bombers of a generation earlier. This generated demand for a new generation of greatly improved bombsights that could be used by a single- crew aircraft and employed in fighter-like tactics, whether high-level, low- level, in a dive towards the target, or during hard maneuvering. A specialist capability for toss bombing also developed in order to allow aircraft to escape the blast radius of their own nuclear weapons, something that required only middling accuracy but a very different trajectory that initially required a dedicated bombsight. As electronics improved, these systems were able to be combined together, and then eventually with systems for aiming other weapons.

Mechanical computers can be either analog, using smooth mechanisms such as curved plates or slide rules for computations; or digital, which use gears. Mechanical computers reached their zenith during World War II, when they formed the basis of complex bombsights including the Norden, as well as the similar devices for ship computations such as the US Torpedo Data Computer or British Admiralty Fire Control Table. Noteworthy are mechanical flight instruments for early spacecraft, which provided their computed output not in the form of digits, but through the displacements of indicator surfaces. From Yuri Gagarin's first manned spaceflight until 2002, every manned Soviet and Russian spacecraft Vostok, Voskhod and Soyuz was equipped with a Globus instrument showing the apparent movement of the Earth under the spacecraft through the displacement of a miniature terrestrial globe, plus latitude and longitude indicators.

Creepback (or creep-back) is the tendency of bomber aircraft using optical bombsights to release their weapons aimed at target markers before time, leading to a gradual spread backwards along the bombing path of the concentration of bombing. It was a particularly noted phenomenon of the Royal Air Force's Bomber Command night attacks during World War II. The most dangerous time of a bombing raid in World War II was during the bombing run, the approach to the target. The bomber pilot was required to hold the aircraft straight and level, unable to take evasive action in the face of fierce enemy air defences over the target, including searchlights, night fighters and anti- aircraft fire. The temptation was strong for the bomber crew to 'flinch' and release their bombs slightly before reaching the target indicator flares that marked the aiming point.

These "vector bombsights" all shared the basic vector calculator system and drift wires, differing primarily in form and optics. As bombers grew and multi-place aircraft became common, it was no longer possible for the pilot and bombardier to share the same instrument, and hand signals were no longer visible if the bombardier was below the pilot in the nose. A variety of solutions using dual optics or similar systems were suggested in the post-war era, but none of these became widely used."Target Following Bomb Sight", US Patent 1,389,555"Pilot Direction Instrument and Bomb Dropping Sight for Aircraft", US Patent 1,510,975"Airplane Bomb Sight", US Patent 1,360,735 This led to the introduction of the pilot direction indicator, an electrically driven pointer which the bomb aimer used to indicate corrections from a remote location in the aircraft.

Unfortunately for the Americans, the Stratus clouds covering the city that day were impossible for the men operating their respective Norden bombsights to spot through, forcing the various bomber groups, under the command of Brigadier General Robert F. Travis, to circle over the city three times with their bomb bay doors open, slowly using up fuel and being subjected to the German anti-aircraft guns. Before the fourth run, the 96th and 388th Bomb Groups began leaving to attack the secondary objective of Strasburg, but again failed to spot it and instead deposited their bombs into the Black Forest. Moments later, Luftwaffe fighters returned to engage the bombers, and would continue to harry them until they returned to fighter range. 45 bombers were lost during the mission, and the American doctrine of daylight precision bombing would die after the second raid on Schweinfurt later that year.

During the Second World War, Barnes Wallis developed two large "earthquake" bombs for the Royal Air Force: the five-tonne Tallboy and the ten-tonne Grand Slam, for use against targets too heavily protected to be affected by conventional high explosive bombs. These enormous weapons were designed to strike close by their target, to penetrate deeply into the earth, and to cause major structural damage by the shock waves transmitted through the ground.After sliding into the soil or rock beneath or around the target, the energy of detonation is transferred into the structure or creates a camouflet (cavern or crater) into which the target would fall. In practice, they proved capable of penetrating a significant thickness of concrete if they scored a direct hit, despite not being designed for that purpose by Wallis, who had to work within the accuracy limitations of current bombsights and the resulting low accuracy of the bombings.

The B 18A entered service in June 1944, and quickly became Sweden's standard medium bomber aircraft.Flight International volume 52, 1947. p. 284. As license-built Daimler-Benz DB 605 liquid-cooled, inline engines had become available, they were incorporated into the improved Saab 18B, which first flew on 10 July 1944. Ordered into production as the B 18B dive bomber, the 18B design was further developed into the T 18B, which was planned to be a torpedo bomber variant. Due to difficulties with the torpedoes, however, the T 18B was instead developed into a heavy ground-attack aircraft, mounting a automatkanon m/47 autocannon under the nose. By the late 1940s, the third crewmember's position had been eliminated, reducing the crew of the aircraft to two; the provision of air-to-ground rockets and improved bombsights had removed the requirement for a bombardier. By this time the Saab 18 had established a reputation for suffering a serious rate of attrition, and this led to the decision to outfit all of the surviving aircraft with ejection seats for the pilot and navigator/gunner.Fredriksson, Urban. (1996) "Early Swedish Ejection Seats".