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Footage has been:
- Researched
- Edited
- Narrated
by Look in The Past channel.
Check my Youtube channel for more original history footage videos: https://www.youtube.com/@LookinThePast
Music: Epic Blockbuster 2 by Rafael Krux
Category
📚
LearningTranscript
00:00:10A very interesting topic, which is kind of neglected, is the history and development of
00:00:15helicopters during World War II. In this compilation, I have collected my videos about
00:00:20the different types of the era. So without further ado, let's begin with chapter 1, the
00:00:26Kellett XR-8 and the XR-10, the so-called Flying X. The concept of the helicopter is as old
00:00:34as the concept of flying. Many experimented with it since the beginning of the century,
00:00:39and between the two world wars, the engineers tried several different designs. At that time,
00:00:45it was not clear yet, if the helicopter or the autogyro will be the better approach.
00:00:50The Kellett Autogyro company was betting on the latter, and developed several different
00:00:54types during the 1930s. Their KD-1 design was bought by the US Army in 1935 for evaluation,
00:01:02and was tested under the designation YG-1. Later the prototypes were re-designated as XR-2 and XR-3.
00:01:11These autogyros seemed perfect for the observation role, with their near-vertical takeoff and slow
00:01:17splits. Though the test flights continued on the type until 1943, leading to the XO-60 military type,
00:01:24but by that time the advances in helicopter design made the autogyro concept obsolete.
00:01:31The Kellett company already realized this years before, as by 1939 the Sikorsky VS-300 helicopter
00:01:37appeared. The first designed to use a single engine to drive the main rotor and the rotor on the tail
00:01:43as well.
00:01:45So Kellett, after more than a decade of building autogyros, now concentrated their efforts to the
00:01:50helicopter development, and in November 1942 they proposed their new twin rotor helicopter design
00:01:56to the Army Air Force. They opted for a different approach than Sikorsky, and their design used two
00:02:02counter-rotating intermeshing rotors, eliminating the need for a separate rotor on the tail.
00:02:08A similar design was developed in Germany, the Flattner FL-282 Colibri, which used the same
00:02:14intermeshing rotor concept, and was actually used operationally by the Luftwaffe during World War II.
00:02:22The Army initially dismissed the Kellett design as being too complicated,
00:02:26but soon the decision was reversed, and the proposal was accepted in January 1943.
00:02:32In September the same year, a 1 million dollar contract was awarded to them to build two prototypes.
00:02:39Apart from the intermeshing rotor concept, the helicopter's fuselage was unusual as well,
00:02:44being a short egg shape. Though it looked unusual, it used conventional building methods,
00:02:50fabric covering over a steel tube frame, and featured a two-man glazed cockpit. The first prototype was
00:02:57ready at the summer of 1944, and made its maiden flight in August. The first test flights were successful,
00:03:04but it was discovered the helicopter-legged directional stability. So two vertical tail fins were added,
00:03:10which fixed this problem. But the type had trouble with its intermeshing rotor system as well.
00:03:15After a month, it was discovered the rotor blades from the two rotors are sometimes touching during flight.
00:03:21So the Air Force ordered Kellett to develop a separate rigid rotor system to fix this problem.
00:03:28The second prototype started its test flights in March 1945, and this type featured two bladed rotors,
00:03:35unlike the first model, that had a three-bladed design. But the new variant caused severe vibrations,
00:03:40and its performance was way below the expectations. So it was dropped. The development of the new rigid
00:03:47rotor system, designed for the first prototype, was soon also cancelled, as it turned out the
00:03:53implementation would require the extensive redesign of the whole drivetrain.
00:03:58In the end, the XR-8 was sent to service trials with its original rotor system in early 1946. But
00:04:05since the
00:04:06Sikorsky R-4 helicopters at this time were in service for more than two years, and even the newer R
00:04:11-5 and R-6 models
00:04:13entered service, it was soon decided the Kellett design is not worth the time and effort anymore.
00:04:19The program was cancelled, and the prototypes were handed over to the National Air Museum.
00:04:25But that was not the end of Kellett's intermeshing rotor design. Already in 1945, a bigger version of the XR
00:04:32-8 was on
00:04:33the drawing board. This new variant, the XR-10, was the company's answer to an Air Force request for a
00:04:41helicopter, which should be able to carry at least 10 passengers or similar cargo weight. The XR-10 followed
00:04:47the design principles of the earlier model, but it was much larger and stronger. While the XR-8 was 22
00:04:55feet 7
00:04:55inches long, with two 36 feet diameter rotors, an empty weight of 2,320 pounds, and a maximum takeoff
00:05:04weight of 2,975 pounds, and it was powered by just one 6-cylinder engine, developing 245 horsepower.
00:05:13The bigger XR-10 was 28 feet 8 inches long, with two 65 feet diameter rotors, an empty weight of
00:05:209,570 pounds,
00:05:23and a maximum takeoff weight of 15,410 pounds. And it was powered by two 15-cylinder
00:05:30Continental engines, each of them developing 525 horsepower. The new design was the biggest
00:05:38and most powerful helicopter when it appeared, able to carry 10 fully equipped troops or 4,000 pounds of
00:05:45cargo, and reach 120 miles an hour speed in horizontal flight. But maybe its best feature was that it could
00:05:53fly on just one engine with normal gross weight, at altitudes up to 4,600 feet. The helicopter's two
00:06:02engines were mounted on outside nassals, so the whole interior of the airframe could be used for
00:06:07cargo space, and the engines drove the rotors through long driveshafts.
00:06:15The XR-10 made its maiden flight in April 1947, and though it proved itself of being a very versatile
00:06:21and capable aircraft, the same problems were noticed with the rotor system as on its predecessor.
00:06:27This time the company managed to fix the problems, the test flights were deemed successful,
00:06:32when the helicopter was delivered to Wrightfield in June 1948.
00:06:38The testing continued there until October 1949, when the prototype crashed due a control failure.
00:06:44Despite the crash, the Air Force planned to order 10 of these helicopters for further testing,
00:06:49and finally it seemed the Kallet Egg Beeters might enter service. But sadly for the type,
00:06:54the budget of the Air Force was reduced by the Congress in that year,
00:06:57the Kallet XR-10 became one of the victims of the budget cuts. The company even planned the 16-seat
00:07:04civilian version, but sadly because of the termination of the project, this never made
00:07:09it further than the mock-up stage. Only two units were built from the XR-8 design,
00:07:15and two from the XR-10, which were tested by the military. But sadly, technical problems and the
00:07:20budget cuts prevented these interesting helicopters to enter mass production.
00:07:26One of the surviving XR-8 models is under restoration at the National Museum of the United States Air Force.
00:07:35Chapter 2. The German Focke Achilles F8223
00:07:42Many countries around the world were interested in helicopters between the two world wars,
00:07:46and Germany was no exception. Many successful and less successful designs were developed at that time.
00:07:53But the first practical usable helicopter was the Focke-Wulf FW-61, which was first revealed in 1936.
00:08:01This design could take off vertically, hover, and had good directional control,
00:08:05and it used the pitch-on-the-rotor blades for the control of the aircraft, just like modern helicopters do.
00:08:12The only two prototypes were built, these showed a glimpse of what helicopters are capable of,
00:08:16and made the army and especially the navy interested in the new vehicles.
00:08:21After Heinrich Focke was forced out from the Focke-Wulf company in 1936,
00:08:25the next year he established a new company with Gert-Achkelis to develop helicopters,
00:08:30as the Air Ministry was interested in an improved version of the FW-61.
00:08:36The first plans were drawn up for two designs. A training version of the new type, which would have been
00:08:41a
00:08:41slightly larger two-seat version of the earlier model, and a bigger cargo variant, basically an
00:08:47enlarged version of the FW-61, with similar twin-rotor layout, but bigger size and featuring an enclosed
00:08:54cockpit and cargo bay. This was the F8-266, the civilian version, which was planned to be able to
00:09:01carry six passengers, or same amount of cargo. The German Lufthansa was very interested in the type,
00:09:07and ordered it in 1938. But not just civilian use was planned for the new aircraft. Both the German
00:09:14Navy and the Air Ministry were interested in the military applications. The military version of the
00:09:18type received a new designation, F8-223, and the requirements it had to meet were the ability to
00:09:25carry 700 kg of cargo and reach at least 160 km an hour speed. The first military modification,
00:09:33the V-1 prototype was finished in September 1939, and after the war broke out, the civilian variance
00:09:39development was stopped altogether. The prototype went through countless ground tests, as initially
00:09:46it had many problems to work out. One of the main ones was the unwanted vibrations and low service life
00:09:51of the originally planned Brahmo 323D engine, which was then changed to the newer 323Q type. After the
00:09:58ground tests and many hours of tethered flight tests, the first free flight happened in August 1940.
00:10:04Two months later in October, the prototype was presented as a demonstration flight,
00:10:08where it managed to reach 182 km an hour speed and an altitude of 4880 m, well above the required
00:10:16numbers.
00:10:21The new helicopter was much bigger than its predecessor. With a length of 12.25 m and a wingspan
00:10:27of 24.5 m from rotor end to rotor end, it was similar sized as a light bomber.
00:10:32It had an empty weight of 3,180 kg and a maximum take-off weight of 4,315 kg.
00:10:46The helicopter used a single Brahmo 323 radial engine, producing 1,000 hp.
00:10:53The maximum speed of the production variant was 176 km an hour, and its cruise speed was 134 km an
00:11:01hour.
00:11:02With 490 liters of fuel capacity, it had a range of 437 km, or 2 hours and 20 minutes of
00:11:09flight time.
00:11:10And it had a service ceiling of 4,875 meters.
00:11:16Some of the production variants featured one 7.92 mm machine gun in the nose,
00:11:21and the helicopter had a cargo capacity of around 1,000 kg.
00:11:26And if needed, they could carry two 250 kg bombs, or two depth charges against submarines.
00:11:35The demonstration was very successful, and the Air Ministry had initial plans to order 100 units,
00:11:40in 5 different variants. Though the V-1 prototype crashed in February 1941 during a test flight,
00:11:47but the V-2 was finished soon after. This variant featured a new cockpit design as well.
00:11:52And it didn't take long for the V-3 variant to arrive, which was built incorporating the new
00:11:57Ministry requirements. By this time the plan to build 5 different variants was dropped,
00:12:01and one single multi-purpose aircraft was needed. The V-3 variant was chosen to be used as a base
00:12:07for
00:12:07the production variants. The manufacturing of the new helicopters however was very problematic,
00:12:13and hampered by the Allied bombings from the beginning. The factory at Delmenhorst was destroyed
00:12:19in 1942 in an Allied bombing raid, together with the units in production and the V-2 and V-3
00:12:25prototypes.
00:12:27Though the manufacturing was moved to Laubheim, a year later this facility was bombed too,
00:12:32and only 7 aircraft survived. The finished helicopters were tested and used in various tasks.
00:12:39The V-11 participated in a search and rescue operation in 1944 in Holland,
00:12:44when a DO-17 bomber crashed there, but the helicopter was damaged in the process.
00:12:48The V-14 was sent to help recover the V-11 and the crashed plane.
00:12:55The V-16 was tested in various mountain operations in Austria.
00:12:59This is the actual unit in the background footage you are watching now.
00:13:03It was tested how the helicopters perform at higher altitudes,
00:13:06and how usable are they in the transport role. The F-223 could easily transport a cannon,
00:13:12weighting 840 kg to a position at several thousand meters of altitude,
00:13:17which without a helicopter would have taken 20 men and a day and a half to deliver.
00:13:24The production again was moved to Tempelhof, where though the plans were to establish a production line
00:13:29to assemble several hundred of the new helicopters. In the end, only four additional units were finished.
00:13:34And only one of them entered service, the rest was captured by the advancing Red Army.
00:13:40At the end of 1944, only five of these machines were in usable state.
00:13:44Three of them were assigned to the 40th Cargo Transport Group, flying supplies to
00:13:48surrounded cities and performing rescue missions.
00:13:53Not only the F-223 type flu missions though.
00:13:56In the same unit, they were paired with several of the Flattner FL-2A2 Colibri type.
00:14:04After the war ended, one of them, the V-14, was flown from France to England in September 1945,
00:14:10and landed at the RAF Beely base, making it the first helicopter to cross the Channel.
00:14:15The British used the aircraft for test flights to examine the type, but in October it crashed
00:14:20in an accident. At least one unit was ferried over to the US, but its fate is unknown.
00:14:26After the war, two incomplete units were taken over and finished in Czechoslovakia,
00:14:30and flown under the designation VR-1.
00:14:35In France, with the assistance of Henry Focke, a development of the F-223 was built,
00:14:40under the name SE-3000, for civilian use. Only three of these were built.
00:14:50Though the F-223 was built in very small numbers, and didn't have a big part in the war,
00:14:55they demonstrated the possibilities of the use of the helicopter in many tasks,
00:14:59like search and rescue, cargo delivery to hard to reach areas, and so on.
00:15:03So they definitely earned their spot as one of the most unique vehicles of World War II.
00:15:17The first US helicopter tested by the US Armed Forces.
00:15:23Two experiments with helicopters and autogyrals were conducted since the beginning of flight,
00:15:28with different interesting designs, but the biggest steps in this field were made in the 1930s,
00:15:33with the appearance of stronger, more reliable engines, and advances in aerodynamics.
00:15:39The Germans were the ones who managed to build the first actually successful design,
00:15:43which was even stable enough to be presented in a sports arena to the audience.
00:15:48The Focke-Wulf FW-61 model appeared in 1936, and it could land and take off vertically,
00:15:55and showed good directional control.
00:15:58A young American engineer, Winn LePage witnessed one of these demonstrations during his travels in Europe,
00:16:04and he was very impressed. Earlier he already worked on some autogyro projects at various companies,
00:16:10and on several ideas partnered with another engineer, Havilland H. Platt.
00:16:15Platt actually tried to purchase the license to build the Focke-Wulf design in America,
00:16:19but they couldn't reach an agreement with the German company.
00:16:24After returning to the US, LePage started lobbying with the helicopter idea at the US Army Air Corps,
00:16:30and at the end of 1938 joined up with Platt to start a new company together to develop their own
00:16:35helicopter as a private venture following the design principles of the Focke-Wulf FW-61.
00:16:42Their timing actually was perfect, as before that year the Army Air Corps had no funding for
00:16:47helicopter research. But with war looming over Europe, the Army gained more funding for new
00:16:52developments, and just in 1938 a new bill was passed supporting the research of helicopters for
00:16:58military use. Now with the funding available, the US Army published specifications for a helicopter design
00:17:05in August 1939, calling for new Rotary Wing aircraft designs with at least £1200 load capacity.
00:17:13By this time, LePage and Platt already made good progress in the design work of their PL-3 model,
00:17:19which they modified to the Army specifications to participate in the competition.
00:17:24In May 1940, the Army Evaluation Board started to review the entire designs.
00:17:30Undeniably, after the success of the FW-61, the Platt-LePage PL-3, which closely followed its design,
00:17:36had an advantage. After reviewing the entire designs, the PL-3 was chosen
00:17:41over the Sikorsky proposal, and accepted under the designation XR-1.
00:17:49A contract was awarded to the company in July to build a flying prototype and a static testbed,
00:17:54and delivered them by January the next year. The arrangement of their design was very similar to
00:18:00the FW-61, using a conventional metal tube framework covered by fabric, and a single
00:18:06400hp Pretend Whitney radial engine positioned in the fuselage, driving two rotors mounted side-by-side
00:18:13on wing-shaped pylons. These pylons were designed to generate some lift during forward flight.
00:18:21The helicopter featured a two-seat tandem cockpit, with the pilot sitting in the front and the observer
00:18:26behind him.
00:18:30Though the company made good progress earlier with the design work, they failed to keep to the contract,
00:18:35and the prototype was only delivered almost three months late. And this gave an opportunity to Sikorsky
00:18:40to secure funding from the Army for his work. The XR-1 made its first lettered flight in May 1941,
00:18:48which was followed by several more, until finally, at the end of June, the first free flight happened.
00:18:54But the design showed problems right from the start. It suffered from excessive vibrations,
00:18:59and the helicopter was hard to control. The automatic collective pitch control
00:19:03could even cause control reversal during tight turns.
00:19:07Though several different solutions were tried to fix these problems, the company couldn't fully
00:19:11get rid of them before the prototype was delivered to Wright Field in early 1943 for the early acceptance
00:19:17trials. The problems continued to slow down the progress of the development,
00:19:22and the whole year was spent trying to resolve them, by installing a new rigid rotor system,
00:19:27new blades, giving the aircraft greater range of control, and many more.
00:19:34But the company's test pilot Lou Levitt had still no confidence in the helicopter,
00:19:38and the critical close-circuit flight test was delayed many times.
00:19:43Finally, May 1943, Cornel Frank Gregory, the director of the Rotary Wing projects,
00:19:48himself visited the Platte-LePage airfield to inspect the development.
00:19:53After spending some time observing the test flights, in early June, he finally had enough of the
00:19:58constant delays, and climbed into the pilot seat himself, and completed the close-circuit flight with
00:20:03around 100 miles an hour average speed, without any major difficulties.
00:20:09This might sound bad at first, but it was actually good news for the project.
00:20:12As it showed, the problem was not with the machine, but rather with the men at the controls.
00:20:17And this led to the company very soon signing up a new test pilot, Jim Ray.
00:20:22Things were looking up, and finally the tests were underway.
00:20:26Until, during a test flight in July, a rotor broke, and a helicopter crashed.
00:20:32As it turned out, the cause of the crash was a basic human error.
00:20:36A ferrying on the rotor hub was not secured, and failed.
00:20:40But the aircraft was so seriously damaged, it took more than a year to return it to flyable condition again.
00:20:46Luckily for the project, back in October 1941,
00:20:50the Army Air Force already approved funding for a second prototype.
00:20:54This variant, the XR-1A, incorporated many changes and improvements,
00:20:59based on the test flights of its predecessor.
00:21:02The most prominent was the changing of the cockpit and the seating arrangement.
00:21:08In the new bubble canopy, now the observer occupied the front seat,
00:21:12and the pilot was sitting behind him.
00:21:14The new model also received a stronger variant of the Platt & Whitney engine,
00:21:19now producing 450 horsepower.
00:21:29The XR-1A was 29 feet 4 inches long, with a wingspan of 65 feet.
00:21:34It had a weight of around 3,500 pounds empty, and 4,730 pounds loaded.
00:21:45The helicopter was powered by a single pretend Whitney radial air-cooled engine,
00:21:49developing 450 horsepower.
00:21:51And with this engine, it could reach a maximum speed of 110 miles an hour.
00:22:04The new XR-1A made its first flight in October 1943, with Buck Miller at the pilot seat.
00:22:10The upgrades on the new variant seemed to work, as the helicopter showed better performance,
00:22:15and more importantly, more precise controls than the first variant.
00:22:19Testing continued at the Platt-LePage factory until summer 1944,
00:22:23when the helicopter completed a cross-country flight from Ediston to Wrightfield.
00:22:28Here the Army Air Force test pilots took over, and the helicopter performed numerous flights until October,
00:22:34when during a test, the right rotor hub failed, and the prototype crashed.
00:22:38Instead of being scrapped, the rack was sold to former test pilot Lou Leavitt,
00:22:42who restored it to be used in his company, Helicopter Air Transport.
00:22:48But soon the helicopter was sold again to another former Platt-LePage employee,
00:22:51Frank Piasetsky.
00:22:53He did not plan to fly the aircraft, instead the Aftrain was modified,
00:22:57and served as a base for the mock-up of his design, the PA-2B Ringwing.
00:23:03The crash of the second prototype seemed to be the end of the XR-1 project.
00:23:07But the company actually received another contract from the Army Air Force,
00:23:11just before delivering the XR-1A to Wrightfield.
00:23:14To avoid looking to be biased towards the Sikorsky design, the Army ordered seven units from the
00:23:20Platt-LePage helicopter in January 1944.
00:23:24The first of the YR-4A models should have been delivered a year later in January 1945,
00:23:29but this actually never happened.
00:23:31The company was on the verge of bankruptcy after years of development,
00:23:35and this hampered the production greatly.
00:23:39Finally, in March 1945, the contracts with the Platt-LePage company were terminated.
00:23:44By this time, the Sikorsky R-4 helicopters were in service with the armed forces,
00:23:49and already a hundred of them were delivered.
00:23:52But the design principle of the XR-1 made a faint comeback a few years later,
00:23:57in the form of another helicopter.
00:24:00Back in 1943, when the Platt-LePage company sought capital investment,
00:24:05McDonnell invested in exchange for the Wright of the twinrotal concept,
00:24:09and later used it in the development of their XH GD-1 whirl-away design.
00:24:14But this helicopter was plagued with the same problems as the XR-1,
00:24:18and in the end lost out to the Piassetsky H-RP-1.
00:24:24Though the Platt-LePage XR-1 in the end was unsuccessful,
00:24:28and the company went bankrupt soon after the cancellation of the army contracts,
00:24:31it still stands as the first experimental US Army helicopter,
00:24:35and its development was a great training ground for many young engineers.
00:24:42Chapter 4. The Sikorsky R-4
00:24:44The first helicopter used in combat by the US armed forces.
00:24:50The concept of the helicopter was not new by the 1940s.
00:24:53Many experimented with it since the beginning of the century.
00:24:57And between the two world wars, the engineers tried several different designs
00:25:00to build a commercially usable helicopter.
00:25:04The first actually successful design was built by the Focke-Wulf company in 1936,
00:25:09with their FW-61 model, which could land and take off vertically,
00:25:14used the rotor pitch for control, just like on modern helicopters,
00:25:17and had good directional movement.
00:25:21It's no surprise, the military mines also closely followed the development of helicopter designs.
00:25:26And there were several different types developed in Germany before and during World War II,
00:25:30such as the Focke-L Galis F8223 or the Flattner FL-282 Colibri.
00:25:38But the first single engine, single rotor helicopter was developed on the other side of the Atlantic,
00:25:44by Igor Sikorsky.
00:25:46In 1938, while he worked at the United Aircraft Corporation,
00:25:50he managed to convince the directors that he could achieve a breakthrough in the rotary aircraft field,
00:25:54and got their permission to work on his own design and build a prototype.
00:26:00His design, the VS-300, was finished about a year later,
00:26:03and made its maiden flight in September 1939, with Sikorsky at the controls.
00:26:09He was the first designer to use a single engine to power both the main rotor and the anti-torque
00:26:14one
00:26:14on the tail.
00:26:15This proved to be so successful, most modern helicopters still use a similar setup.
00:26:21The VS-300 was tested in different trials and with different configurations and controls,
00:26:26and set several world records.
00:26:28But when the US Army Air Corps had a design competition in early 1940 for a helicopter design,
00:26:33at first the plot de page PL-3 was chosen, which was a more conventional design,
00:26:38very reminiscent to the FW-61 or the F-223, with its engine positioned in the fuselage,
00:26:45and using twin rotors in a side-by-side arrangement.
00:26:49This design was accepted by the Army Air Corps as XR-1.
00:26:53A contract was signed in July, which specified the flying prototype to be delivered by January next year.
00:26:59But slow construction and problems caused a three months delay,
00:27:02and this gave an opportunity to Sikorsky to secure funding for his work.
00:27:08He visited Wrightfield in May 1940, and presented his new design, then called VS-316,
00:27:14and showed film recordings about his VS-300 model,
00:27:18demonstrating its controls and agility through various tasks.
00:27:22The Army liked his new design, but since the funding for the new helicopter project
00:27:26was already allocated for the plot de page XR-1, they had very limited resources to fund further designs.
00:27:32Three months later Sikorsky submitted a proposal to build the first prototype of the VS-316 for
00:27:38just $50,000, which the Army accepted, and they signed the contract in January 1941,
00:27:44and the design received the Army designation, XR-4.
00:27:48It was named number 4, because the XR-2 and XR-3 designations were given to two Kelet designs.
00:27:57While Sikorsky worked on his new design, the XR-1 went through his testing,
00:28:01and turned out to be a very troublesome aircraft, with numerous folds.
00:28:05So much so, that the design problems were still not fully fixed when the war ended.
00:28:11If you are interested in the detailed history of the XR-1, keep an eye on the channel,
00:28:15because we will take a look at that helicopter in a separate video soon.
00:28:19If you haven't subscribed yet, now is the time to do it.
00:28:24The new Sikorsky helicopter quickly took form,
00:28:26as most of its features were based on the earlier VS-300 design.
00:28:31It had a tube frame body, covered with fabric, and a fully enclosed cockpit, featuring dual controls.
00:28:37The prototype was powered by a 165 horsepower engine, and made its maiden flight in January 1942.
00:28:45The initial design featured two additional lifting rotors on the tail, but these were soon dropped.
00:28:51During the following months, the new helicopter went through various trials,
00:28:54to demonstrate the accuracy of the controls.
00:28:57Some of them might seem funny today, but back then, helicopters were all new.
00:29:01So the demonstrations included lifting a bag of eggs, then returning them to the ground,
00:29:06delivering a ring to the hands of Sikorsky, or picking up and landing passengers on a rope ladder.
00:29:12A more practical test was conducted in April, to demonstrate the helicopter's capabilities,
00:29:17including vertical and horizontal maneuvers, speed and altitude demonstrations,
00:29:22and to prove the helicopter is still controllable in autorotation, with the engine turned off.
00:29:28The Sikorsky design passed all these tests safely, with the test pilot Les Morris in the cockpit.
00:29:34After these tests, the Army observers deemed the prototype ready,
00:29:38and requested it to be flown to Wright Field for further trials, instead of delivered by truck.
00:29:43The preparations for the 761 mile flight were soon underway.
00:29:48First by testing the helicopter on shorter flights,
00:29:51then on 13th of May, the long trip from the Sikorsky side to Ohio began.
00:29:56The flight to Wright Field took five days, with 16 hours and 10 minutes spent in the air,
00:30:00and setting two unofficial records.
00:30:02A distance record of 92 miles, and a 1 hour and 50 minutes endurance one.
00:30:09After further testing conducted at Wright Field, the Army officially accepted the helicopter as XR-4
00:30:15at the end of May, and in December they ordered initially 15 YR-4A models for service testing,
00:30:21later adding 14 additional units to the order in January 1943.
00:30:26These variants featured a stronger, 185 horsepower engine, and a larger 38 feet rotor,
00:30:32and with additional modifications implemented during testing and production.
00:30:37In the end, three of them were finished as YR-4A, and 27 as YR-4B variants.
00:30:45The B version originally featured a bomb rack, with the ability to carry 300 pound bombs,
00:30:51but on the production variants this was deleted.
00:30:56In May 1943, another demonstration was held, when a landing target was painted on the deck of a tanker ship.
00:31:03The helicopter first practiced landings and takeoffs with the ship anchored,
00:31:07and later as the ship was underway, first at 5 knots, then the speed was raised up to 15 knots.
00:31:13Despite the increasing speed and difficulty, it proved itself,
00:31:17performing numerous landings and takeoffs without problems.
00:31:20In this demonstration, the pilot of the Air Force was Colonel Frank Gregory,
00:31:24who was actually a key figure in the success of the design.
00:31:28He also flew Sikorsky's earlier VS-300 helicopter, and gave valuable feedback on it.
00:31:33And he also had a big part in the decision for the Army to invest in the VS-316 design,
00:31:38as a backup for the failed XR-1.
00:31:42Later the same year a contract was signed for 100 R-4B variants.
00:31:46From these, 40 were assigned to the Army Air Force,
00:31:4919 to the US Navy and Coast Guard, under the designation HNS-1,
00:31:53and 41 were sent to Britain under land lease.
00:32:03The Sikorsky R-4 was 48 feet 4 inches long, including the rotors, and 12 and a half feet tall.
00:32:10It had an empty weight of 2,011 pounds, and a maximum takeoff weight of 2,540 pounds.
00:32:21The helicopter was powered by a Warner Super Scarab R-550 engine, producing 200 horsepower.
00:32:27With this engine, the R-4 could reach a top speed of 82 miles an hour, and a cruise speed
00:32:33of 65 miles an hour.
00:32:35It had a range of 153 miles, and a service ceiling of 12,000 feet.
00:32:49The XR-4 was the original prototype, powered by a 165 horsepower engine.
00:32:56The following YR-4A were further test versions, using a stronger 185 horsepower engine and larger
00:33:03rotors.
00:33:04Three of them were built.
00:33:07The YR-4B variants featured further improvements, and originally featured a bomb rack.
00:33:1227 were built.
00:33:15The R-4B was the production variant, using a 200 horsepower engine,
00:33:19and the larger diameter rotors, similar to the YR-4A variants.
00:33:24100 units were built.
00:33:26The H-N-S-1 was the US Navy designation of the helicopter.
00:33:31In British service, the type was named Hoverfly-1, and was used by the Royal Air Force and the Royal
00:33:37Navy.
00:33:38The S-54 model was a single modified type, with a third seat for an observer behind the rotor.
00:33:53The Sikorsky R-4 was the first successful helicopter used by the US armed forces,
00:33:58and they started flying missions soon after they entered service.
00:34:02Though their use was very much experimental.
00:34:06The first notable mission of the type happened in January 1944, still on US soil.
00:34:11When the USS Turner destroyer on the way back to New York, suffered an internal explosion and sunk.
00:34:17The survivors were taken to the Sandy Hook hospital, and Lieutenant Commander Erickson flew his
00:34:22helicopter there, carrying blood plasma, delivering it in less than 15 minutes,
00:34:27which could have taken hours by car.
00:34:31During World War II, these new helicopters were used around the Pacific,
00:34:35and mostly in the Burma-China-India theater.
00:34:37For reconnaissance, observation and career missions, they delivered parts to repair units,
00:34:43and were also used for medical evacuations.
00:34:46The first air rescue mission was flown in April 1944,
00:34:49when an R-4 rescued a downed pilot and his three passengers.
00:34:53They had to be carried one by one because of the limited lifting capacity of the helicopter.
00:34:58Later during the war, many similar rescue missions followed,
00:35:01and the number of men evacuated by the type during its short service life in World War II
00:35:05is probably more than a hundred.
00:35:09From the originally ordered hundred units, the final one was delivered to the armed forces in January 1945.
00:35:15Though this type was the first successful and mass-produced helicopter used by the US forces,
00:35:20it was very basic and underpowered, but it paved the way for its successors.
00:35:26It was quickly replaced with newer types, like the Sikorsky R-6 and the bigger R-5,
00:35:32which both made their maiden flights back in 1943, and were introduced before the end of World War II.
00:35:38The R-6 by most measures was just an improved version of the R-4 model,
00:35:43keeping the main rotor and transmission, but using a stronger 240hp engine and a new streamlined fuselage.
00:35:51The R-5 on the other hand was designed as a more robust, bigger and stronger aircraft,
00:35:56with higher speed carrying capacity and endurance than its predecessor,
00:36:00using a much stronger 450hp engine.
00:36:05We will also take a look at these helicopters in future videos.
00:36:10The Sikorsky R-4, though it had a relatively short service life, laid down the basics for the controls
00:36:15and layout for the helicopters that followed, and it was a milestone in aviation.
00:36:20It was quickly replaced by newer designs, but as the first mass-produced helicopter,
00:36:24and the first type used by the US armed forces in combat, it will always be remembered.
00:36:32Chapter 5. The Piasecki H-RP-1, H-RP-2 and H-21.
00:36:37The so-called Flying Bananas, the first tandem rotor helicopters of the world.
00:36:44Though helicopter developments were well on the way on both sides of the Atlantic during World War II,
00:36:48the resulting designs were mostly smaller vehicles, like the Sikorsky R-4 in the US,
00:36:54or the Flattner FL-282 in Germany.
00:36:57There were experiments with larger twin-autor helicopters as well,
00:37:01like the Platte LePage XR-1 or the German FA-223,
00:37:05but these often run into problems because of their insufficient engine power and complicated construction.
00:37:12While the US Army and the Air Force actively pursued helicopter developments,
00:37:16the Navy neglected this area for quite a while.
00:37:19But after a 1943 Senate hearing, they were instructed to look for suitable designs.
00:37:25But since the main helicopter manufacturers, Sikorsky and Platte LePage already worked on
00:37:30Army contracts, and had no free manufacturing or development capacity,
00:37:33the Navy turned towards smaller designers.
00:37:36One of those was Frank Piasecki, a young engineer who earlier worked at the Kelet Autogyro Company,
00:37:42and later at Platte LePage as a control engineer on the XR-1 design,
00:37:46and built years of experience with autogyros and helicopters.
00:37:51His first working design, the PV-2, was a small single rotor aircraft, which flew in April 1943.
00:37:58Though this flight was actually not intentional.
00:38:01The helicopter was lifted off accidentally during a tune-up test,
00:38:04and thus by accident it became the second helicopter to fly in the US.
00:38:10The Navy was interested in more powerful designs,
00:38:13which could be used for troop transport or rescue missions.
00:38:15So when Piasecki proposed an unprecedented large twin rotor transport helicopter to them,
00:38:21which could carry 8 passengers or around 2000 pounds of cargo at 100 miles an hour speed,
00:38:26they were very interested.
00:38:29In October 1943, the Piasecki PV-2 was demonstrated at the Washington National Airport,
00:38:35and its construction and flight performance impressed the Navy officials.
00:38:38So in January 1944, his company was awarded a contract to develop his large twin rotor design.
00:38:45Though the new design, the PV-3, had a fairly strange look,
00:38:49it was a combination of Piasecki's earlier experiences.
00:38:52While he was working at the Platte LePage company on the XR-1 design,
00:38:56he noticed that the side-by-side twin rotor configuration worked better flying sideways,
00:39:01and it also needed strong pilots to support the rotors, which added unwanted weight and drag.
00:39:06Two problems which could be both avoided if the rotors would be installed in tandem.
00:39:12He also raised the tail of his helicopter to keep the two rotors from touching,
00:39:16and to keep the downwash of the front rotor away from the rear one,
00:39:20resulting in the distinctive look of the helicopter, which soon earned the nickname the Flying Banana.
00:39:26The PV-3 was the largest helicopter when it was completed, with 47 feet 3 inches length,
00:39:32and using two 41 feet rotors, and having an empty weight of 4,279 pounds.
00:39:39The design had a conventional construction with a steel tube frame and fabric covering,
00:39:44and it was powered by a single 450 horsepower continental radial engine,
00:39:49mounted at the rear of the helicopter.
00:39:52Though this design was different from earlier experiments, and had a lot of promise,
00:39:57this didn't mean it was simple. The long fuselage housed a two-man cockpit with tandem seating,
00:40:03and to drive the two main rotors with a single engine, it used a series of driveshafts and free transmissions.
00:40:11As the complicated design came from a small company, the navy chose a backup in case it fails.
00:40:17Interestingly, the backup model they picked was the McDonnell X-HJD-1 Whirlaway,
00:40:22a design based on the earlier failed Platte LePage XR-1, which Piasetsky also worked on.
00:40:28But the McDonnell design showed the same problems the XR-1 had in the past, and it was eventually cancelled.
00:40:36Meanwhile the PV-3 made its maiden flight in March 1945,
00:40:40and during the test flights it managed to reach a speed of 95 miles an hour and lift 1800 pounds
00:40:46of weight.
00:40:48The first unit was kept as a company property,
00:40:50so it received the navy designation X-HRP-X, where the second X indicated it was a company prototype,
00:40:57while later navy models were designated X-HRP-1.
00:41:02During this time the company received another contract from the navy, for a smaller six-seat helicopter.
00:41:08This design was the X-HJ-P-1, which became the H-UP-1 retriever,
00:41:14but we will take a look at that model in a separate video later.
00:41:18The first flights of the PV-3 were done without the fabric covering on the body,
00:41:23which was later applied improving the speed of the aircraft.
00:41:27As with most early helicopters, this design had many teething problems as well.
00:41:31The first prototype had very heavy controls, but that was quickly corrected by the engineers.
00:41:36And as it was found over the testing, the transmissions needed much higher quality parts,
00:41:41than the initially used automotive components, which caused several malfunctions until they were replaced.
00:41:48By 1946 two additional prototypes were finished for the navy,
00:41:52from which the second one was the pre-production version for the H-HRP-1.
00:41:56These variants were upgraded to 600 horsepower Pratt & Whitney engines.
00:42:02The testing was satisfactory, and the navy ordered 20 production models in 1947.
00:42:08Most of these were supplied to the Marine Corps, where being the first helicopter with sufficient
00:42:12carrying capacity, they were used to develop helicopter assault tactics.
00:42:17They remained in service until 1953, but the experiences with the H-RP-1 soon led to an improved variant,
00:42:24the H-RP-2, which featured a revised, more streamlined fuselage, with an all-metal skin, and more importantly, an
00:42:32improved cockpit.
00:42:34The original design's cockpit was positioned closer to the center of gravity.
00:42:38However, experiences on the H-RP-1 showed that the pilots usually pivoted the helicopter around the cockpit.
00:42:45So on the new variant, it was moved forward, giving better visibility to the pilots, who were now sitting side
00:42:51by side.
00:42:52The H-RP-2 was 7 feet longer than its predecessor, and thanks to its better aerodynamics, its speed increased
00:42:58to 105 miles an hour.
00:43:01But the redesign and the new fuselage increased the weight of the H-RP-2 with more than a thousand
00:43:06pounds.
00:43:07And because it used the same 600 horsepower engine, it could now only carry five troops,
00:43:12which given the size of the helicopter, was not economical.
00:43:16In the end, only five units were built from this variant.
00:43:19But the new fuselage and cockpit arrangement served as a base for the new, more powerful H-21 model.
00:43:27After the success of the H-RP-1, in 1949, Piasetsky proposed their new H-21 model to the US
00:43:33Air Force.
00:43:35This helicopter was based on the H-RP-2 design, and was initially intended as an Arctic rescue aircraft,
00:43:40to operate in harsh weather conditions and temperatures as low as minus 54 Celsius.
00:43:47The new design was an all-metal construction, and finally featured a powerful engine, to fit the size of the
00:43:52fuselage.
00:43:54The new 1,250 horsepower Wright R-1820 engine greatly increased the helicopter's lifting capacity and speed over its predecessor.
00:44:04The new model made its maiden flight in April 1952, and lived up to the expectations.
00:44:10The speed of the new helicopter increased to 125 miles an hour, and its cargo capacity to 20 troops.
00:44:17The Air Force was interested in the design, and after the test flights, they ordered 32 search and rescue H
00:44:23-21A variants,
00:44:24and 163 H-21B troop transport variants.
00:44:29The production A version used a 1250 horsepower engine, while the B model featured an even more powerful variant,
00:44:37developing 1425 horsepower, resulting in a lifting capacity fitting for its size, as it could carry 20 troops.
00:44:47The Army also placed orders for the new helicopter, which they designated H-21C.
00:44:53The type was accepted into service in 1953, and in the same year it set an altitude record,
00:44:59with 22,100 feet, and 2 days later a speed record, with 146 miles an hour.
00:45:07In August 1956, it became the first helicopter to accomplish a non-stop cross-country flight in 37 hours.
00:45:14Sadly, Piasetsky was not able to enjoy the success, as in the same year he was forced out of his
00:45:20company,
00:45:20which became the Vertol Corporation, and later in 1960 it was acquired by Boeing.
00:45:36This helicopter was 52 feet 6 inches long, and used two 44 feet diameter rotors.
00:45:43It had an empty weight of 8,650 pounds, and a maximum takeoff weight of 15,200 pounds.
00:45:52It was powered by a single air-cooled Wright R-1820 engine, producing 1425 horsepower.
00:46:01With this engine it could reach a top speed of 127 miles an hour, and had a cruise speed of
00:46:0698 miles an hour.
00:46:08Its combat range was 265 miles, and had a service ceiling of 9,450 feet.
00:46:17The helicopter could carry 20 fully equipped troops,
00:46:21and optionally they were armed with 50 caliber or 7.62 mm door machine guns.
00:46:36The YH-21 models were the service test variants. 18 were built.
00:46:41The following H-21A model was the production, service and rescue variant, with upgraded 1250 horsepower engines.
00:46:51The H-21B model was the troop transport version, featuring 1,400 and 25 horsepower engine, and limited armor protection.
00:47:01163 were built for the US forces, 10 for Japan, and 10 for France.
00:47:07The SH-21B was a rescue version of the H-21B.
00:47:13The Army version was the H-21C model.
00:47:17333 were built for the US forces, and 98 for the French air force.
00:47:22The X-H-21D was a test version, built with two Tull-Bosheft engines, but it didn't go to production.
00:47:31And finally the civilian variants of the helicopter were named Model 42A and 44A, B and C.
00:47:48The Army version of the H-21B was used in many different roles, mostly as a transport,
00:47:52but it was also used in the cold northern regions, by the US Air Force and the Royal Canadian Air
00:47:58Force,
00:47:58to maintain the early warning radar sites.
00:48:01There were also medieval variants, the Marine Corps evaluated them for aerial assault,
00:48:05and several experimental versions were tested for gunship operations,
00:48:09with different door guns and even flexible guns under the nose.
00:48:15The first combat use of the type however, happened in the Algerian war by the French forces,
00:48:20who ordered 98 of the type.
00:48:23Flying missions along with the smaller Sikorsky H-34 types,
00:48:27the H-21 was tested as a gunship, featuring fixed machine guns and rocket pots.
00:48:31But soon it was found, they lacked maneuverability for those missions,
00:48:35and they were just used as troop transports, equipped with different door guns,
00:48:39either 50 caliber machine guns or 20 millimeter cannons.
00:48:46In 1961, the type was deployed to South Vietnam, where again they flew transport missions,
00:48:52being the only big helicopter that could transport the whole squadron together.
00:48:57They were again armed with different door guns, either 7.62 millimeter or 50 caliber machine guns.
00:49:04But despite using self-sealing fuel tanks, the big helicopter proved to be vulnerable to enemy fire,
00:49:09especially its unprotected control cables and fuel lines.
00:49:15In 1962, the type was re-designated to CH-21.
00:49:20Originally designed for cold weather conditions, the CH-21 also run into performance and reliability issues
00:49:26in the hot and dusty South Vietnam.
00:49:29The engines had lower output in the hot climate, resulting in reduced lifting capacity,
00:49:34so they were often overstressed, and only lasted about 200 hours.
00:49:40By 1964, the new Bell UH-1 Huey entered service, which could perform many of the roles better than the
00:49:46CH-21.
00:49:48But the smaller Bell design couldn't fully replace them, as it could only carry a maximum of 5 troops.
00:49:54The CH-21 was used alongside the Huey until the arrival of the new CH-47 Chinook in 1965,
00:50:02which was a true replacement for the type.
00:50:05Later that year, they were called back from Vietnam, and finally in 1967, the type was fully retired.
00:50:14Interestingly, their replacement, the Chinook, was actually a descendant of the CH-21,
00:50:19as by that time Boeing acquired the former Piasetsky Corporation.
00:50:25Though the flying bananas were early designs, and they had a relatively short service life,
00:50:30the helicopters built by Boeing after them, like the CH-47 Chinook and the CH-46 Sea King,
00:50:37all carried their legacy, and many of them are still in use today.
00:50:45Chapter 6. The Flattner 282. A German WWII inter-mashing rotor helicopter.
00:50:53Just like in many other countries around the world, the Germans were interested in the helicopter concept
00:50:57between the two world wars, and many successful and less successful designs were developed at that time.
00:51:03But the first practically usable helicopter was the FA-61, which was first revealed in 1936.
00:51:09It could take off vertically, hover, and had good directional control,
00:51:13and used the pitch-on-the-rotor blades for the control of the aircraft, just like modern helicopters do.
00:51:20Though only two prototypes were built, these showed a glimpse of what helicopters are capable of,
00:51:25and made the Army, and especially the Navy, curious.
00:51:29The Flattner helicopter came from a line of experimental designs,
00:51:32developed by Anton Flattner during the 1930s, with the support of the German Navy.
00:51:38The Navy at that time was looking for a small aircraft, which can land on ships,
00:51:41and fly between the shore and the ships with ease.
00:51:43So they supported Flattner's experiments, hoping his designs could be what they are looking for.
00:51:50The first of this family was the FL-184, developed in the mid-1930s,
00:51:54but this aircraft was actually not a real helicopter, but an autogyro.
00:51:59In 1935 Flattner received a contract from the RLM to build the prototype.
00:52:03Though this experimental aircraft was a successful design, and showed promise,
00:52:07it was cancelled when the only prototype was destroyed in a fire.
00:52:11Flattner's work however didn't stop here, and the next variant, the FL-185, was an evolution of the concept.
00:52:17He developed the autogyro into a gyrodine, featuring a free-bladed lifting rotor,
00:52:22and two horizontal pulling ones on each sides.
00:52:25The FL-185 could take off and land vertically and hover in place,
00:52:29which was possible because in flight the two side propellers worked in opposing directions,
00:52:34giving the same effect as the single tear-roton on modern helicopters.
00:52:38The prototype was built and testing began in 1937, and though the design showed promise,
00:52:43it was considered too complicated and was abandoned.
00:52:46But the test results led to newer designs, and the next in line was the FL-265.
00:52:52This aircraft developed in 1938 was the first of Flattner's designs to use intermeshing rotors.
00:52:59The German Navy already ordered six prototypes to be built, even before the design was finalized.
00:53:05They were excited about the new aircraft, because this new design left the autogyro concept,
00:53:10and put the emphasis on the main lifting rotors,
00:53:12and was a big step towards the modern helicopters we know today.
00:53:16The first flight was concluded in May 1939, piloted by Richard Perlia,
00:53:21which was followed by many other tests, including naval trials, landing on cruisers and U-boats.
00:53:28The Wehrmacht also tested these new vehicles, not just as reconnaissance,
00:53:32but for lifting heavy loads or towing barges during river crossings.
00:53:39The new aircraft is not as vulnerable and helpless as many were suspecting, tests were conducted.
00:53:45Fighter planes simulated attack rounds on the FL-265, but they failed to score any hits
00:53:49after several attempts, thanks to the maneuverability of the helicopter.
00:53:54The aircraft was actually seen as such a success, it was meant to go into large-scale production,
00:53:59but by that time its successor was already in the works, and that was the FL-282 Colibri.
00:54:05The FL-282 was a completely new design. It used similar intermeshing rotors as the FL-265,
00:54:12and it was a fully operational helicopter without any horizontal puller engines.
00:54:17It had a lightweight tubular welded frame, featuring a tricycle landing gear and a center pilot compartment.
00:54:23It used the SH-14 7-cylinder air-cooled engine, which was lightweight and low maintenance.
00:54:30This engine, though it had relatively low output, of only 160 horsepower, needed low maintenance,
00:54:35and it could run up to 400 hours without servicing.
00:54:40The FL-282 was a small aircraft, only weighting 760 kg, and had a length of 6.5 meters.
00:54:47So this low power engine still allowed the helicopter to reach 150 km an hour maximum speed,
00:54:53and have a range of 170 km. At the rear of the aircraft a big horizontal stabilizer was added,
00:55:00and the steering of the FL-282 was done by the combination of the rudder and the changing of the
00:55:05rotor pitch.
00:55:08The rudder was also a necessity, as the Colibri was able to go into autorotation if needed,
00:55:13which made it a very safe machine, but when the rotors were not turning,
00:55:15the only way to control the aircraft was with the rudder. The helicopter was too small to carry any
00:55:21weapons, but by design the landing gear and rotors could be removed, so it could be stored in tight
00:55:25spaces, as there were plans to even use them on submarines. The first three prototypes were built
00:55:32with fully enclosed cockpits, but interestingly the later production models were only partly enclosed or
00:55:37completely open. The new helicopter made its maiden flight in October 1941,
00:55:45with Ludwig Hoffmann at the controls. The test continued all the way through 1942,
00:55:50with different modifications applied to newer prototypes, different tail surfaces and changes
00:55:55to the propeller drives. After the installation of the second seat at the rear, the internal fuel tank
00:56:02was changed to two smaller tanks on the sides. They also tested new three-bladed rotors, and though
00:56:08they resulted in smoother operation, they were deemed unnecessary. Similar tests against fighter aircraft
00:56:15aircraft were conducted, as on the former FL-265 version, as the military staff still had no experience
00:56:20how the fragile, slow-moving aircraft could survive an attack from the faster, well-armed fighter planes.
00:56:26A test against Focke-Bulf-190 fighters resulted in the conclusion that at higher altitude, above 700 meters,
00:56:32the aircraft could aim at the helicopter, though given the big speed difference only for brief moments,
00:56:37especially if the helicopter performs evasive maneuvers. At low levels and on difficult terrain, the helicopter
00:56:43can outmaneuver the fast fighter planes easily. They were tested against ground fire as well,
00:56:49shooting several different caliber weapons at an unmanned hovering FL-282. It was found that the moving
00:56:55rotors had a very slim chance to be hit, and even when hit, the bullets did little damage to them.
00:57:02After the first flights, the Navy immediately ordered 45 units for evaluation. They were tested and used
00:57:08under different climates, from the Baltic Sea to the Mediterranean. The Navy planned to use the Colibri
00:57:15as a submarine spotter. It was a very stable and very maneuverable aircraft, and it could land on warships
00:57:21even in bad weather and strong winds. The landing and takeoff were tested many times, sometimes on heavy
00:57:28seas, but the FL-282 managed to land safely on the ships every time. Special landing platforms were
00:57:35constructed on different ships, and the Colibri had to land on these roughly 5x5 meter platforms on the
00:57:41moving ships. The FL-282 actually flew more hours than any other World War II German helicopter design,
00:57:49as it went through very strict testing. By 1943, some of them were used operationally, protecting
00:57:55convoys in the Mediterranean, though at that time only around 20 of them were built in total.
00:58:01Later in the war the Wehrmacht planned to use them as artillery spotters. Luckily the FL-282 was
00:58:06designed as a two-seater from the beginning, so it was no problem adding a second seat at the rear.
00:58:14The big plans for using these helicopters for many different roles were hindered by the constant
00:58:18Allied bombings though, as the manufacturing had to be relocated several times. In 1943 the operations
00:58:24were moved to the east, because of the intensifying Allied bombings near Berlin. But later in 1945 they
00:58:30were moved back, as the Red Army was approaching from the east. Though in 1944 a contract was signed to
00:58:37build a thousand units, their factory was destroyed by Allied bombings, so large-scale production of these
00:58:42great helicopters never happened. By the end of the war most of them were destroyed, though the Allied
00:58:48nations raced to get their hands on one. Only three of them survived. One was taken to the Soviet Union,
00:58:56another one to the USA, but both of them seemed to vanish. The only restored model today is on display
00:59:01in the Midlands Air Museum in England. After the FL-282 Flattner was already working on other designs,
00:59:09including the bigger FL-285. This helicopter was a larger version of the 282, able to carry bombs and
00:59:17using the more powerful AS-10C engine. After World War II, Flattner was moved to the US under Operation Paperclip.
00:59:27Later he became the lead designer for Kemen Aircraft Corporation, and some of the designs still carry the
00:59:32legacy of the World War II FL-282. A good example for that is the Kemen K-MAX.
00:59:39Which is still available today.
00:59:45Hope you guys enjoyed this video. Please leave a like, subscribe to my channel,
00:59:48and in the comments let me know if there's any interesting events or vehicles you'd like to see.