A trebuchet could crash a helicopter

The Flettner helicopter Fl 282 Kolibri

Transcript

1 The Fl 282 V12, trunk identification CJ + SF, had a two-thirds high glass paneling of the driver's cab in the nose of the fuselage. All machines built had numbered gearbox covers, here the number 03. The Flettner helicopter Fl 282 Kolibri Theodor Mohr (ADL sponsor) reviewed and expanded version of the first publication in FLUGZEUG No. 4/1987 to 4/1988 This documentation deals with one During the Second World War little known aircraft, more correctly a helicopter, by Anton Flettner. Its type designation was Fl, the machine received the name of a humming bird as an appropriate epithet, namely KOLIBRI. In memory of ADL sponsor Theodor Mohr, who died a decade and a half ago, his work on the first German helicopter to be deployed at the front is presented here on the ADL website. The presentation of the work has been adapted to the medium of the Internet and more illustrations have been added. Some passages were rearranged or summarized in an appendix, such as overview drawings, identification sheets and tables. Günter Frost (ADL) Contents Contents ... 1 Preliminary remark ... 2 The beginnings in Germany ... 2 Establishment of our own company and first helicopter developments ... 5 The creation of the Flettner Fl Die Fl 282 test model The Technical Office and the Fl page 1

2 The large-scale production of 1000 Fl 282s at BMW The Navy and the Fl 282 development The Fl 282 in the General of the Air Force's war diary at the Commander-in-Chief of the Navy Front testing on the ship Drache and U-Jäger KUJ Airborne Squadron 3./196 for special aircraft Das inglorious end of the hummingbirds, whereabouts of Fl 282 after the war Overview drawings and identification sheets Building description Fl 282 B-0 and B-1 (Status:) Airplane program (V-Muster, Anton Flettner) Delivery plan No. 222 Edition Compilation of flight times, take-offs and Terms of the FL Acknowledgment List of sources Abbreviations used Illustrations Preliminary remark The interested reader should not only be provided with technical data from the cell manual and the data sheet of the E -stelle Travemünde, but also that previously unpublished RLM and OKM documents should be made accessible, either indirectly or directly related to the development, testing and manufacture of this helicopter. A detailed part is devoted to the extremely great interest of the Navy in the KOLIBRI and its testing with the Navy as well as with the E -stelle Travemünde (under verifiable Fl 282), whereby the protocols are partly quoted verbatim. Likewise, the testing of the Fl 282 by the on-board pilot squadron 3/196 (for on-board special aircraft) with excerpts from the war diary of the 196 on-board pilot's group is mentioned. The large-scale order for 1000 pieces Fl 282 from the B.M.W.-Werke should also be discussed, because the previous publications only briefly refer to it and mostly in identical texts. It is noticeable that all publications have one thing in common: Nowhere is there any hint at least of the date of this very unusual construction contract for an aircraft engine plant. The present elaboration cannot claim to be complete because the authentic material available to the author is not extensive enough. However, despite the gaps that became apparent when working on the material at hand, he hopes that this publication will help to complete the history of the development of German aircraft construction up to 1945. (Please note: Numbers in square brackets indicate the source at the end of the documentation). The beginnings in Germany In December 1934, the development group in the RLM (LC II, 1) held lectures in the presence of State Secretary Milch, which were to lead to important decisions for future air armament. In the protocol under section 4) rotary wing aircraft, the following is noted: The development of rotary wing aircraft is to be given priority. All work that has already started must be accelerated accordingly, as these aircraft are likely to be important for land and sea use in the future [1]. How true this prognosis was to become was only fully confirmed in the many armed conflicts after the Second World War, particularly in the Korean and Vietnamese wars. In the civilian sector, too, and especially in the rescue sector, the helicopter has become indispensable nowadays, although this type of aircraft has been technically perfected more and more over the course of time. At that time, however, the field of helicopters, their development and construction as well as basic research in this sector was still completely new territory to which the technicians and designers embarked. The rotary wing aircraft appeared in the overview plan of the processing areas at LC II, 1 (Dec, 1935) under the heading: Sports, training, training and special aircraft (Referat II / 1a). The following samples are listed: Fl 184, FW 61, Project FW (later FW 186) and LC 30 license Focke-Wulf [2]. Page 2

3 The C 30 should be discussed briefly because the Navy was already interested in using it as an on-board aircraft. The C 30 was a pure gyroplane construction (Autogiro) by the Spaniard Juan de la Cierva from the year For license building at Focke-Wulf (FW) it should be noted that the rights for the replica of the C 30 were not granted as early as 1933 from FW, as can be read in a recent publication on helicopters. From February 1935, the license negotiations initially took place with the Hamburger Flugzeugbau GmbH (abbreviation Ha, later B&V), but failed for financial reasons. From July 1935, the Focke-Wulf-Werke entered negotiations. As a result of foreign exchange difficulties, FW could only start building under license in December 1935, after the foreign exchange had been secured for 36 C 30 units [3]. The preliminary attempts to use the gyroplane C 30 for on-board purposes began on at the E -stelle See Travemünde. They ended with a negative result, due to the inadequate performance, the more than inadequate flight characteristics in gusty weather and the poor visibility for the pilot during deck landings on small platforms. A further development of the C 30 for military use was therefore abandoned [4]. (left and below): Two photos from a series of images that were taken in October 1944 at the new company headquarters of Anton Flettner GmbH in Schweidnitz (Silesia) and show nine Fl 282 helicopters in parade position. In the first picture, Anton Flettner proudly presents his products. The second photo shows that the machine in the foreground is the V14 CJ + SH. The factory halls of the Flettner company appear on the left edge of the picture. Page 3

4 (left): Dipl.-Ing. Emil Arnolt, chief designer at Flettner-Werke, and Hans Fuisting, chief airman of the company, as well as a mechanic in front of the halls of Anton Flettner GmbH. (Carsten Arnolt Coll.) (Bottom left): Chief pilot Hans Fuisting, Dr.-Ing. Kurt Hohenemser, Anton Flettner and Dipl.-Ing. Emil Arnolt. (bottom right): Anton Flettner, taken in the late 1920s. (Photo Encyclopaedia Britannica) page 4

5 Establishing your own company and first helicopter developments In order to give an overview of Anton Flettner's work, the history of his helicopter development should first be briefly discussed. Anton Flettner () made a name for himself as the inventor of the Flettner oar as early as 1917. The Flettner rotor, conceived as a ship propulsion system by wind, was his idea, but it was unsuccessful. In the early thirties, Flettner began work on his first test helicopter. A two-blade rotor with a diameter of 30.5 m was arranged above the relatively small fuselage, the blades of which were held by tension wires that ran over a tensioning tower that rotated along the rotor's axis of rotation. A 30 HP Anzani motor with a lag screw was mounted quite far out on each blade. This direct drive of the rotor blades meant that no torque had to be compensated. The fuel was supplied from a tubular tank in front of or behind the engine. The experimental device was made in wood and plywood in 1934 at the company Segelflugzeugbau Edmund Schneider, Grunau (Riesengebirge). In the same year it broke during a tethered flight. Flettner's first test helicopter of the year It is worth noting the spinning tower above the driver's seat, over which the four huge rotor blades were held by means of tensioning wires. Two 30 HP Anzani motors were used for the drive, which were mounted on two opposite blades about 2/3 of the blade length and each had a lag screw. Below is a photo of the crash landing, which ended in a total write-off. page 5

6 The establishment of the Anton Flettner G.m.b.H. as a small development company especially for helicopters is said to have taken place in Berlin in 1935. As the earliest, dated document, the author has a letter from the Wehrwirtschafts-Inspektion (W.I.) III, Berlin, to the RLM, which concerns companies that manufacture air forces. It is noted in this that the W.I. III was only informed that this company had been assigned important tasks by the RLM (LC II) [9]. The same inspection sent the confidentiality agreements to Flettner, Berlin-Johannisthal, Segelfliegerdamm 27, for signature. In the following years, the Fl 184, 185 and 265 were created in Berlin as the forerunners of the Fl 282. Fl 184 In January 1935, Flettner received the development order from the RLM for an autogiro test aircraft (gyroplane with three-blade rotor), of which three SV samples were provided. The dummy inspection took place in June 1935. Only one test sample, the Fl 184 V1 D-EDVE, was used. It was destroyed by an operator error on its first flight in December 1936. Its design was still somewhat similar to the Autogiro C 30, which was built under license by Fokke-Wulf at the time. A Sh 14 with a normal propeller was used for propulsion [5, 5a]. Gyroplane Fl 184 V1, registration D-EDVE. A Siemens SAM 14 A radial engine (145/160 hp) with a normal propeller provided the propulsion. The rotor blades were without a drive and only provided lift when the head wind made them rotate. page 6

7 Fl 185 The development order for this came from the RLM in February 1937; two SV samples were planned. Its designation in the aircraft development program was: Helicopter conversion 184, because the planned Fl 184 V3 was used in the construction of the FI 185 V1. It was financed by the sum insured for the destroyed Fl 184 V1 and around RM as a grant from the RLM. The dummy inspection was in April 1937 [6]. The Fl 185, a flight wrench with a three-blade rotor, had a boom on both sides of the fuselage for torque compensation, at the ends of which sat adjustable pusher propellers driven by long-distance shafts. The right one produced rearward thrust, the left one forward, so that the total moment exerted by both on the fuselage was balanced with that of the main rotor. The Fl 185 V1 D-EFLT was completed, which carried out various flights in 1938 with good results, albeit at low altitudes. Flight screwdriver Fl 185 V1, registration D-EFLT, from the year A radial engine Bramo Sh 14A (Bramo 314) was used. The engine power was distributed to the three-blade rotor via a gearbox and to two adjustable side propellers via connecting shafts. The latter sat on horizontal outriggers and served primarily to compensate for torque, for this purpose they were designed in a push-pull arrangement on the port side and in a pull arrangement on the starboard side; in addition, they also generated propulsion. The front of the engine was equipped with a cooling propeller. Page 7

8 Fl, with the design and construction of the helicopter Fl 265, the future conception of the Fl 282 was already apparent. The Fl 265 showed considerable improvements over its predecessor models. E.g. the double rotor with intermeshing rotor blades. In addition, the automatic switchover from helicopter to gyroplane flight (auto-rotation, from the V4) and the option to switch back to helicopter flight. 6 test samples (serial number) were used. The Fl 265 V1 D-EFLV completed its maiden flight in May 1939 after extensive ground testing (first full throttle run, first tethered flight at a height of 20 cm) under flight captain Richard Perlia. (top left): The Fl 265 V1, here already with the D-EFLV approval, completed its maiden flight in May 1939. Captain Richard Perlia was at the wheel. (at the top right and below): The Fl 265 V1 originally had a three-bladed cooling propeller, but was later equipped with a six-bladed fan. (right): Captain Perlia on a demonstration flight in front of political dignitaries and members of the Air Force and Navy. page 8

9 An extensive military test was carried out in cooperation with the Kriegsmarine, e.g. Deck landings on an approx. 25 m 2 landing platform on the cruiser KÖLN (see also page 25). The Fl 265 V1 was decommissioned on. The V3 was lost due to operating errors due to an impact fire. The Fl 265 V5 (out of service) and the Fl 265 V6 (out of service) were still parked at the Flettner company in November 1942. Its repair was postponed several times and ultimately no longer carried out [7]. The Fl 265 with the registration TK + AN was tested in the summer of 1940 in the large wind tunnel at Chalais Meudon (Paris). (top and left): A Fl 265 with the registration TK + AN was examined in the Chalais-Meudon wind tunnel (near Paris) in the summer of 1940. The exact identity of this machine is unknown. In any case, it is not about the Fl 265 V3, which has been found in various publications, because the V3 was verifiably lost in August 1939 and was therefore no longer available for wind tunnel investigations in the summer of 1940. (below): Winter flight operations with the Fl 265 TK + AN. Page 9

10 Three-sided view Flettner Fl 265 page 10

11 (right): The Fl 265 V5 had the trunk identification GI + SB. What is striking about this machine is the chassis with the aerodynamically shaped wheel and strut covers. The picture was taken around Berlin-Johannisthal. Single images from a color film dating from around 1940/41. The Fl 265 TK + xx (possibly the TK + AN shown on the previous page) is shown during a rescue exercise at an inland lake surrounded by forests: a life-size doll is recovered from a rubber dinghy. The film can be found on the Internet at the address bordhubschrauber-für-km /. Unfortunately, the film sequence is shown reversed, so that the beginning of the trunk identifier can only be identified as TK if the images are flipped horizontally, as is the case here. (Source: Romano Archives) Page 11

12 The Flettner Company's Last Years of War Caused by the increased Allied air raids on Berlin, the relocation of Anton Flettner GmbH to Schweidnitz in Silesia (approx. 50 km southwest of Breslau) began in August 1943, which took several months due to the deterioration in transport options took. The Fl 282s available at the company were also flown over there to continue the test program. In February 1944, the workforce was around 120, which was also the highest. Due to the approach of the Soviet Army in Silesia, the relocation back to Berlin-Tempelhof took place in January / February 1945. Under these circumstances, of course, orderly work or even production was out of the question. In addition, because a few days after the arrival, the rest of the company's equipment was destroyed by a night attack on Tempelhof. The rest of the Flettner company was then evacuated to Bad Tölz (Upper Bavaria), where two Fl 282s were also flown. The story of Anton Flettner G.m.b.H. ended there when American troops marched in, insofar as it is of interest for this documentation. The Flettner Fl 282 Kolibri and its winged competition, the Fieseler Storch - successor Fi Another photo from the series of pictures that were taken in October 1944 at the Flettner company headquarters in Schweidnitz (Silesia) and show nine Fl 282 helicopters in parade position. In the foreground is the V14 with the trunk code CJ + SH. page 12

13 The creation of the Flettner Fl 282 The Fl 282 was probably Anton Flettner's most successful helicopter development. It is no exaggeration to say today: It was the best helicopter of its time. The exact date when the RLM issued the development order for the Fl 282 is not known. However, it can be assumed with certainty that construction work began as early as 1939 in addition to the ongoing testing of the Fl 265. All test results and experiences that had been gained with the Fl 265 experiments were reflected in this. Work on the Fl 282 V1 had progressed so far in mid-August 1941 that it could be used as a gear trainer on the ground. For this purpose, the test vehicle was anchored (tied), but could lift and float up to a certain height depending on the length of the bondage.125 hours 39 minutes were used for this test. In the event that this device was destroyed or the tests were to be interrupted for a longer period as a result of any breakdowns, the FL 282 V4 was intended as a replacement test stand. The test pilot Ludwig Hoffmann, who joined Flettner in 1939 as the successor to the company aviator Perlia, was able to carry out the first free flight on the Fl 282 V2. As a result of design changes to the cardan shafts, further flight tests from March 1942 resulted in significant improvements in the handling of this helicopter. The Fl 282 V2 was taken out of flight operations and parked on. The rotor gearbox and the motor were removed for use in other V-designs. With the Fl 282 V3, Hoffmann was able to perform two high-altitude flights on. With the first it reached m above the starting point, with the second (from to o'clock) m in 36 minutes. The Fl 282 V2 had a fully glazed driver's cabin and carried out its maiden flight on, the pilot was Ludwig Hoffmann. Page 13

14 In the Fl 282 V3, the driver's cab was only glazed in a narrow frontal area. The machine had end caps on the horizontal stabilizer and had the trunk identification GF + YC. In addition, it should be noted that the Fl 282 V2 and V3 were provided with a fully or partially glazed cabin. From the V5 onwards, the driver's seat was either completely open or only had a plexiglass cladding on the front and sides. Various versions of the horizontal stabilizer were also tested. The V3 had an end cap on the right and left on the straight fin. A V-shaped fin, similar to that on the Cierva C 30, was installed on the V23. From January 1942 the Fl 282 V5 flew, which had various changes compared to the V3 (tail unit, fuselage, driver's seat). View into the driver's cab of the Fl 282 V12: (top left): The instrument panel behind the half-height front panel: variometer, airspeed indicator, turn indicator, rotor tachometer, rotor blade angle indicator; below it guide compass. (top right): The device board on the left contained the following fixtures from diagonally above to diagonally below: Altimeter, double pressure gauge for gasoline and lubricant, double display for oil temperature (above and below transmission), double display for engine oil (inlet and outlet) , Ignition switch. (left): on the left side wall the FuG 19 (above), throttle and blade adjustment lever, rope release lever, trim lever (next to the FuG 19.) page 14

15 The Fl 282 V12, trunk code CJ + SF, when shunting by 2 MS. Rolling under your own steam was generally prohibited on the Flettner helicopter. The driver's cab was provided with a two-thirds high glass cladding and allowed a good view in all directions with the exception of the rear. Calculations showed that by reversing the direction of rotation of the rotor, the directional stability would have to be significantly better, especially when the flight is throttled and in gyroplane flight. To confirm this, the V8 was set up as a transmission test stand. Flight tests from September 1942 with the V9 and V15 proved the theoretical knowledge. The course stability was still so good that the V9 simply left out the entire fuselage behind the engine firewall. The flight attempts went perfectly. This V9 was the project for use on large submarines as seen by the Navy and designated as a modification pattern in the form of a standing cylinder (Fl 282 U). In addition, a rotor version with three rotor blades each was on the test stand, which ran particularly smoothly, which, however, was of no consequence for military use. The Fl 282 V6 had a completely open driver's seat without any glass paneling. Although this gave the pilot excellent all-round visibility, it should have been a very uncomfortable affair in bad weather. Above the nose wheel, the landing light was helpful, especially when landing on ships. Page 15

16 The Fl 282 V21 and V23 were designed as two-seaters, with the observer sitting with his back to the pilot behind the engine mount in the fuselage. To do this, it was necessary to remove the fuselage tank and replace it with two unprotected, cylindrical containers on the outside of the fuselage, on both sides of the driver's seat. The Fl 282 V21, trunk identification CI + TU, was designed as a two-seater. (above): Factory pilot Fuisting is at the wheel, Anton Flettner looks over the side of the ship in the rear seat. (left): The second crew member sat with his back to the pilot behind the engine in the fuselage. The fuel supply had to be moved to two cylindrical tanks to the left and right of the driver's seat. (below): In an emergency, two people could fit into the rear crew compartment for a short time. Page 16

17 The entire technical testing of the Fl 282 did not take place in Rechlin, as is usually the case with land aircraft, but from August 1942 at the E -stelle See Travemünde. The responsible head of the helicopter and gyroplane testing there was Fl.Stabs-Ing. Dipl.-Ing. Hans Fischer, his colleague Fl.Stab-Ing. Dipl.-Ing. Otto Dumke. After Fischer's crash with a Do 217 (RB + YH) at the E -stelle, in which he was seriously injured, Fl.Stabs-Ing. Dipl.-Ing. Gerhard Geike is in charge of working on this group. Air traffic control and rescue ship GREIF, assigned to the E -stelle Travemünde. The ship was 72 m long and measured at 775 GRT. (Drawing E. Gröner) The Travemünde location was chosen because the air traffic control ship of the E -stelle GREIF, on which the deck tests could be carried out, was located there. There, in cooperation with the Navy, the helicopter testing at sea was less problematic. On the other hand, there was an urgent need to postpone the testing at Flettner from Berlin, which was exposed to an increased risk due to the increasing Allied air raids. Crash landing of Fl 282 V17 on April 13, 1944 on the site of the E -stelle See Travemünde. A wooden platform (approx. 16 m 2) was built on the banks of the Pötenitzer Wiek on the Lufthansa bridge to test and train landing on ship decks. Page 17

Reference should be made to a special experiment carried out jointly with the DVL Institute for Sea Aviation. These were towing tests with a 50 kg sliding body. The suggestion for this came from the head of E.-u.L.Kdos.20, Hptm. Von Winterfeldt, who on the 3rd and also carried out the tow plows in Gotenhafen from a submarine hunter. The Fl 282 should not only be used in the anti-submarine defense as a reconnaissance aircraft to support the submarine fighters, but also actively participate in the fight against submarines by dropping bombs [8]. Also worth mentioning is the following excerpt from the June 1944 monthly report of the E -stelle Travemünde: On, a comparison flight between the Fl 282 (pilot of the company Flettner) and an FW 190 (pilot Ltn. Eisenlohr of the E.Kdo.25) took place in Schweidnitz. instead of investigating the chances of a fighter being hit by a helicopter. The evaluation of the film and the pilot's report are z. Not yet available. At heights over 100 m, the hunter succeeds in briefly targeting the helicopter. Close to the ground, especially in confusing terrain, the hunter has little chance against a helicopter. The bombardment sensitivity was also examined, assuming that the mathematical probability of hitting a moving rotor blade is much lower than that of hitting a rigid wing. Added to this was the consideration that it must be extremely difficult to shoot at and hit the slow helicopter from a fast fighter. He was able to protect himself on all sides with short defensive movements that the hunter cannot understand. In addition, ground fire tests were carried out on the running rotor blades, since the helicopter is more sensitive to ground fire than to air fire. For this purpose, an unmanned, tied up hummingbird was used, which could not be brought down despite several hits in the rotor blades. (above): Detailed view of the rotor heads of a Fl 282. The gears were a particularly difficult component, which is why they were specially identified by numbers on the housing covers. The gearbox with the number 0.3 can also be found on the title photo, so that the picture opposite was probably also made on the V12, trunk number CJ + SF. (below): Installation of the radial engine BMW-Bramo 314 E in the middle of the fuselage of the Fl 282 below the rotor heads. The petrol tank is easy to see behind the engine. In the two-seater version, the tank had to give way to the observer's position, the fuel supply was instead housed outside in two cylindrical containers on the left and right of the driver's seat (see photos on page 16). Page 18

19 The Fl 282 test samples In the following, an attempt is made to prove the number and characteristics of the Fl 282 V samples actually flown or used as a test stand on the ground using authentic documents only. In previous publications, the number fluctuates between 23 and more than 30. The following sources were used for this list: 1. Weekly reports, monthly reports and order overviews from the E -stelle See Travemünde (not available in full). 2. The delivery plan No. 222/2 of the current state of the hummingbirds for the 3/196 season (). 4. Compilation of the flight times, take-offs and run times of Fl 282 (Orig. FLETTNER list from). 5. Excerpts from the flight log from the test pilots Dipl.-Ing. C. Bode (Focke-Achgelis) and Dipl.-Ing. G. Geike and Dipl.-Ing. H. Fischer (both E -stelle Travemünde). At FLETTNER, in addition to the serial numbers (etc.) specified by the RLM, internal fabrication numbers were still in use, for example for the Fl 265 V1 - V6 (W. No.) and for the Fl 282 V7 starting with the W. No.. In delivery plan No. 222/2 the additional type designations can be found: V1 to V4 and V7 Fl 282 A V5, V6 to V20 Fl 282 B V8 and V9 Fl 282 4C These are probably arbitrary designations, because in the Travemünder Such additions do not appear on documents. In addition, the V1, V4 and V8 were test benches that never got to fly. There was also no Fl 282 U, as can be read in the following text from the Kriegsmarine. The Navy chose the U for conversion or to indicate that this Fl 282 (further development) was intended for submarines. The verifiable Fl 282 V-Muster Sample Identification 1. Entry in the logbook Use V V V 3 GF + YC Transmission test stand up to, then parked at Flettner, engine and transmission removed. First flight under Hoffmann on, fully glazed cabin, after various changes, renewed flight tests from March 42 until (last flight), parked at Flettner, engine and gearbox removed. fully glazed cabin, enlarged vertical tail, horizontal stabilizer with end plates. On two high-altitude flights under Hoffmann on or m (in 36 minutes) over the starting point. V 4 Reserve test stand for V 1. V 5 GF + YE V 6 GF + YF V 7 CJ + SA From August 42 first deck tests on GREIF in Travemünde, from January 43 continuation of the training at E -stelle until after overhaul at Flettner in Travemünde arrived, is prepared for water landing experiments. Border test on GREIF, from Oct. 42 to Jan. 43 field test on DRACHE by E.- u.l.kdo.20 in the Mediterranean. The total loss on test flight 35 nm NE from Christiansöye under Captain C. v. Winterfeldt. Provided at Flettner for flight tests and instruction of new pilots. From Jan, 43 at E -stelle for training up to V test bench for the reverse direction of rotation of the rotor blades. V Flight attempts at Flettner with a new direction of rotation of the rotor, also with the fuselage completely removed behind the engine fire bulkhead, up to page 19

20 sample registration number 1. Entry in logbook Use V 10 CJ + SD Oct. 42 to Jan. 43 together with V 6 for field testing on DRACHE, then transferred to E -stelle at Flettner for overhaul, incoming inspection at 3./196, flies with Sheet set of V 14. V 11 CJ + SE Intended as a reserve aircraft for operational testing, training up to V 12 CJ + SF V At Flettner taken over by BAL, then gust measurements. J./F.43 at Flettner, briefing of the E-station pilots Dumke and Fischer transfer by Dumke to Travemünde. April 43 Testing FuG 19 (VHF intercom) after 2 h 53 min flight time for overhaul to Berlin (Flettner) Deck landing attempts on GREIF in front of Travemünde. Oct. 43 Damage to ribs on the rotor attachment, rotor set change, blade set for the V 5 (water landing attempts) Cold start attempts Completion of the cold start attempts, prepared for the dropping of explosive devices (2 x FI.WB5) Creation of the preliminary data sheet for Fl 282 B -0 and B-1. March 44 Completion of the sample installation for bombing (Vemag 2 FI.W.B.5). April 44 Transfer by train to Schweidnitz to Flettner, major overhaul. June 44 still at FLETTNER, up to then a total of 412 starts. Intended for long-term engine tests at Flettner, including reverse flight tests with the tail unit removed. V 14 CJ + SH Intended for measurement flights, conversion June 43, on 3/196 without blade set, not ready to fly. V 15 CJ + SI flights with reversed rotor direction, is said to have been captured by the Americans (FE 4614)? V no information. V 17 CJ + SK Dec. 43 Entry control at E -stelle, breakage of the cross-beam of the harness when braking, then locking of all harnesses until the middle section is reinforced. Beginning of the deck landing attempts on a platform (approx. 16 m 2) on the Lufthansa bridge in the Pötenitzer Wiek Bruch with a new landing gear on this platform, pilot Dipl.Ing. Geike von der E -stelle (see photos on page 17). V 18 CJ + SL at 3rd / 1966, will be handed over to E -stelle for further testing. V Attempts to fly backwards with the tail unit removed. V 20 CJ + SN at 3./196 in Pillau, ready to fly. V 21 CI + TU V 22 two-seater, June 44 for partial overhaul in Schweidnitz, in the near future transfer by train to Travemünde. Not specified. V 23 CI + TW two-seater, driver's seat covered with wood on the sides, horizontal stabilizer with V-shape, American prey machine. FE-4613 and T page 20

21 In order to demonstrate to the RLM that the Flettner helicopter was easy to operate and that it behaved very stable in flight, a normal housewife without any previous flight experience was supposedly given the opportunity to climb up alone with the Fl 282 V22 CI + TV after 3 hours of flight instruction . Take-off, flight and landing should be flawless. The Fl 282 V23 CI + TW was a two-seater and had horizontal stabilizers that were curved upwards in a quarter span in the manner of today's winglets. In addition, the entire front part of the fuselage was clad in plywood. Page 21

22 The Technical Office and Fl 282 It was not until around mid-1940 that the Technical Office, not least at the insistence of the OKM, began to deal with the development of helicopters in more detail, without, however, initially providing for a special urgency classification for this work. Below are some excerpts from the so-called GL meetings and meetings of the head of office chaired by General Luftzeugmeister Milch and quoted verbatim. In the case of the latter, the main focus was on checking the currently valid aircraft and engine delivery programs and their feasibility. The selected sections relate only to the Fl 282. Discussions GL 1 / Genst. 6th Ab: Genst. 6th Ab. was informed that GL is not yet responsible for an early start of series production of the type Fl 282. It is asked to postpone the increase in the number of 0 series aircraft from 20 to 30. From Genst. the opinion is expressed that the company FLETTNER offers no guarantee for a quick and timely start of series production. Genst. therefore asks, with regard to the importance of this model, to investigate whether it cannot be made ready for series production and built by another company: The 0 series will be increased from 20 to 30 units: Genst. calls for use in the Navy Fl 282 with 10 aircraft per month and FA 330 with 30 aircraft per month. The helicopter Fl 282 in winter operation. Even during the cold season, the pilot sat practically completely unprotected in the open. Although the first flown prototype, the V2, had a full-view glass canopy, all other test models either received no or only a half-height paneling of the driver's seat. Office chief meetings: In the case of the helicopters, Director Frydag points out that it would be advantageous to split the FLETTNER operation into two parts, provided that the Fl 282 comes into series production at all. FLETTNER is an inventor and not suitable for series production. The prototype construction in Johannisthal was to be continued under the management of FLETTNER, while the series construction would be entrusted to his employee Glauner: Sellschopp: Then come the helicopters, the Fl 282 and the FA 223, one with two machines a month, the FA 233 with five Pieces per month. Milk: Are they already so advanced in terms of development that they can go into series production? I see this small number as a test series. There's the BMW 314 engine, what about it? Only 1 1/2 pieces are built per month. What is FLETTNER intended for? Friebel: It is the aircraft that is to be used in cooperation with the Navy. Milk: what should it do? Friebel: It should be able to rise from small warships. Page 22

23 Kleinrath: The Fl 282 is included in the demand of the naval war command. Frydag: They're trying to land these days, that looks very convincing. I recently did a visit to FLETTNER. Essentially, the company suffers from this: FLETTNER is an inventor and built its own rotor gearboxes. I said to him: The way you do it, you won't get a green branch.You're not set up to do about five transmissions a month. It is very well set up for prototyping and the individual gears are also very good. However, he fights back with his hands and feet to license these things to a cogwheel or gear factory. He claims they can't. He could not be convinced, that might have to be done forcibly. He has to do 1 ½ pieces a month and can barely finish them. FLETTNER is far too poorly supported for the matter. He does the prototyping excellently, but will never get a series finished. Milch: The machine is due to arrive at the end of 1942 and will be phased out again in mid-1944. That is a term of one year and six months, so not even 1½ machines a month. Frydag: I told him: Fl 282 is not ready yet. But he's an inventor: he has something new and then he does something new. If the Fl 282 should really be needed, the FLETTNER operation could be divided into two parts: the small operation in Johannisthal as a FLETTNER prototype, but take away the series production and give it to its manager, Mr. Glauner. The Fl 282 is an unbound helicopter. He comes down and then they grab the thing at this height (indicates about 2 m height), tie the rope at the bottom and pull it through a pulley. These are measures to actually get the thing to this point when the ship is rocking. (Editor's note: This not exactly professional formulation refers to the landing process of the Fl 282 on the deck of a ship). Vorwald: white wagtail? It's a tied up helicopter. Frydag: FLETTNER has that too. A very simple thing, no tail, nothing to it, a square box, no tail unit and nothing. (Author's note: preliminary test for the use of the Fl 282 on large submarines with the Fl 282 V9). Milk: Is there someone sitting in there, or are they already doing that with television? : Kleinrath: Regarding the helicopters, it has to be reported that the army is demanding, among other things, the trifle of Fl 282. We have already replied on the basis of the first documents from GL / C that the army would then have to resolve the capacities, the workers' question, etc., including aviation fuel. It is only a one-time request. Pasewaldt: That is an absolute exaggeration, because the machine cannot be recycled in this number. The uses of this circus plane are so minimal that it would be a crime to make pieces of it. (Editor's note: When hearing the word circus aircraft, Dr. Pasewaldt probably thought of the public flight demonstration with the FW 61 V1 D-EBVU Germany in the Berlin Deutschlandhalle in February / March 1938 by Hanna Reitsch). Kleinrath: Yesterday I pointed out to Colonel Vorwald that during the big demonstration of the winter vehicles for the army there, by mistake, the Fl 282 provided by GL for General Zeitzler had been seen and the army actually pretended to be this helicopter now would have been the solution to his problems. In any case, we have written to the army that there can be no doubt that everything that is demanded of us can only be done with the help of the army: workers, raw materials and supplies. Vorwald: We will only start the matter when we have a clear demand from the army as to how many Fl 282s we should plan for them. Kleinrath: Yes, but we are afraid that the Fl 282 will be shown to the Fiihrer after the Minister for Armaments and Ammunition (Speer) has made himself very strong and the gentlemen of the army have pretended that it was their sled. It is to be feared that suddenly the order comes in from the Fiihrer that the air force has to build part Fl 282 for the army. In my opinion, this should be discussed with the Reichsmarschall so that he can take action against it. Demonstration of the Fl 282 V11, trunk license number CJ + SE, in front of Hitler, Speer, Himmler and other party leaders as well as various Wehrmacht officers. Flettner personally explains the helicopter. Page 23

24: Vorwald: Deposition of the FOCKE-ACHGELIS and FLETTNER helicopters and utilization of the capacity for the hunter companies. Kindling: The helicopter companies were already significantly restricted in the autumn of 1943. The FLETTNER company in Schweidnitz now has 12 design engineers and 88 workshop staff plus 20 unskilled workers, making a total of 120 men. Hermann: For Schweidnitz it would be suggested that the block (FLETTNER) be merged as a working group and that Me 262 be manufactured there. Kindling: There is only one hall in Schweidnitz, half of which is used for the workshop and the other half as a flight hall. Milk: That's where everything ends! We take over this hall! Kindling: The airfield is very small, so we would like to suggest that modifications etc. be carried out there. In any case, the space for a complete hunter production is too small. It is necessary to make a decision on whether to shut down helicopter development entirely. Milk: shut down for the time being! You can continue working there after the war. Prof. FOCKE is supposed to work somewhere in an institute wherever he wants! The entire staff is assigned to more important tasks. Participants in the meetings: Milch, Erhard Friebel, Walter Frydag, Carl Hermann, Rudolf Kleinrath, Kurt Kindling Pasewaldt, Georg Sellschopp, Heinrich Vorwald, Wolfgang Zeitzler, Kurt State Secretary for Aviation and General Field Marshal, from November General Air Master (as successor to Udet) Dipl. -Ing., GL planning office Director in the Reichsmarschall's industrial council (aircraft construction) General-Ing., Development planning in Genst.d.Lw. Colonel-Ing., Head of the 6th Genst.d.Lw. (Armament) Ing., GL / C Manufacturing Dr.jur., Head of the GL / CE (Development) Office Group Colonel-Ing., GL Planning Office Dipl.Ing., Colonel ig, Head of the Technical Office Colonel-General, Chief of the General Staff of Army This picture and the three photos on the next page were taken during a demonstration of the Fl 282 V12 CJ + SF in Rechlin in front of senior officers of an Italian military delegation. Page 24

25 (above): The head of the Italian military delegation welcomes factory pilot Fuisting and congratulates him on the successful demonstration. (right): Anton Flettner (second from right) explains the helicopter to the Italian officers. Page 25

26 The large-scale series of 1000 Fl 282s at BMW As noted in the introduction, this fact is very briefly dismissed by all authors who have dealt with the Fl 282 so far without giving any details. The source of this knowledge about the pieces seems to be the brief note in the B.I.O.S., published in England in 1948. To be Overall Report No. 8, in which something can also be read about a batch of one thousand Fl 282 and an order placed with the BMW works in Munich and Eisenach. After that, even the construction equipment and tools should have been in preparation. The author of this documentation had two years of additional research on the book by H. Mönnich BMW a Century of History (1st part), the entire existing BMW archives, including documents from the Eisenach branch, to the special part: aircraft engines and Combing planes with BMW engines. However, not a single document about the hummingbirds came to light. If nothing was to be found about this voluminous and for an aircraft engine factory unusual building contract for helicopters, at least in this context an RLM contract or some reference to the pieces of BMW 314 E engines needed to build the Fl 282 would have to be one with a special gearbox provided Sh 14 A could have been found. Series production of the Sh 14 A ended in the summer of 1939. Nothing came to light about that either. When studying the RLM's C-Office program and the GL meetings, you get a little closer to the number. In the aircraft program (V series) delivery plan no. 221/1 from, 16 pieces Fl 282 B by the company FLETTNER are specified as a total delivery. Fl 282 B would have been the designation for the series version, but these 16 pieces were still under the V-pattern. It looks different in the next delivery schedule no. 223/1 from. The program again specifies 16 Fl 282 B for FLETTNER. The following is new in the delivery schedule: In addition to FLETTNER, BMWE (stands for BMW-Eisenach) is also listed as the manufacturer with the planning of 150 Fl 282 B units, of which the first machines should be delivered in January 1944. In addition, the procurement of materials for another 500 aircraft was approved. This would record the date on which this great demand first appeared in an aircraft program, which is missing from all authors, after such a demand was submitted by the army to GL in January 1943, but without being taken into account by the RLM. The hummingbirds, if really, would have been built for the army and not for the air force! Already in the next aircraft program No. 224/1 dated, i.e. six months later, it says literally (with reference to Fl 282): All material releases and series preparations previously issued for the issue of this delivery schedule will become invalid. In the 226/1 dated program, the delivery of the Fl 282, which was reduced from 16 to 7, was also withdrawn. That was the final end for the Kolibri after the V-pattern had been stopped in November 1943. Without making more detailed considerations at this point about the feasibility of the aircraft program design of the Luftwaffe command for interested readers, the comprehensive book by H. Boog The German Air Force Command should be recommended for the planning of BMW in the helicopter production, that, apart from the noticeably noticeable shortage of raw materials and labor in 1943, which BMW aircraft engine works in Munich would have been out of the question for an additional aircraft for reasons of space and capacity. At BMW, the production of the BMW 801 for the hunter program and the work on the TL engine BMW 003 also had absolute priority at the time. The BMW 132 A / T was manufactured in the Eisenach plant, and from 1942 engine parts for the BMW 801 and BMW 323. At the end of 1943, parts were also manufactured for the BMW 003 engine. That is, in broad outline, the history of the KOLIBRIs at BMW, of which only 150 were actually on paper in the form of an aircraft delivery schedule. There can therefore be no question of any preparations for the intended start of series production of the F1 282 at BMW. Page 26

27 The Kriegsmarine and the Fl 282 development The naval warfare command of the Kriegsmarine in cooperation with the submarine office (1./Skl.U/III) recognized the advantages of a helicopter as an on-board aircraft at an early stage and dealt with the problem of his aircraft even before the war began Working on various ship units (including submarines) intensely busy. During the early considerations, in addition to the use of the autogiro (gyroplane) and the small airship, the Fi 156 STORCH liaison aircraft, which made the first deck landing attempts on the air traffic control ship GREIF as early as 1937, was considered. The discussions took place, among other things, in a study of the hang-glider or helicopter by Lt.z.S. Lindner her precipitation. In the elaboration, the superiority of the helicopter over the conventional on-board aircraft, which, as would later also become apparent during the war effort, were actually only a weather-dependent occasional weapon of the ships, is clearly emphasized. The final observation is of interest: Consider the introduction of gyroscopes on a larger scale at the U.S. Navy (Keilet KD-1A) and the establishment of an academy for rotary wing issues in the U.S.A. is not too small, because this type has been tested for years and its use proves the positive course of these tests. If this measure of the U.S. Navy gives us food for thought, so the technical lead that Germany has now achieved through the construction of the helicopter spurs us on to take up this question as quickly as possible in order to secure the tactical one through the technical lead. With a letter dated to the Inspection of the Seeflieger (L.In.8), the Naval War Command already drafted a preliminary formulation of the technical and tactical requirements for the development of a helicopter for military purposes. The elaboration of these requirements was based on a film screening () in the RLM about the extensive testing of the Fl 265 in the navy, the above-mentioned study and the own deliberations of the naval command. The development process of the FLETTNER helicopters proposed therein included the development of a two-seater (Fl 282) and a submarine helicopter (Fl 282 U). [18] Field testing of the Fl 265, trunk identification GI + SA, on the light cruiser Cologne. For the execution of ship landings, a wooden platform of 5x5 m was built in the rear part of the hull of the cruiser on the second (raised) triple tower. Page 27

28 Side elevation of the light cruiser Cologne. (Drawing E. Gröner) L.In.8 issued the final tactical and technical requirements for the development of helicopters, which differentiated between three different types of helicopter: 1) helicopter coastal aircraft, use in the coastal apron, 2) helicopter board aircraft, Use of large warships, 3) small helicopter aircraft, use from submarines. [19] The High Command of the Navy stated in its letter dated that the use of enemy submarines in the North Sea and the Skagerrak was taking place to such an extent that the German anti-submarine defense had to fight hard to keep the situation under control. The already presented helicopter, FLETTNER system (FI 265) is considered to be a particularly suitable means. According to information from LC 2, the FLETTNER helicopter Fl 282 is still under development and testing and in the summer of 1940 would be ready for individual copies to be made available. [20] That this information from GL / LC 2 was too optimistic is shown by the development status of the FLETTNER helicopters given as of the date: Fl 265 V1 and V2 in company tests (V3 total loss on), V4, V5 and V6 between and clearly for flight tests (not intended for military use); Fl 282 probable inspection of the working dummy at the beginning of the flight tests with the V1 at the beginning of September (Editor's note: The real first flight with a Fl 282 only took place on! At the time, there was not even a requirement for the development and construction of helicopters the definition of any level of urgency!). [21] More than a year later, the Skl.U / III wrote in a letter: For purposes of anti-submarine defense, the development of the FLETTNER helicopter has been closely followed by the Skl.U / III for 1 ¾ years. Setbacks in the development of the gearbox resulted in the three helicopters in prospect for the anti-submarine defense not being able to be delivered in the summer of 1940 and only now the company is ready again to think of delivering helicopters for front-line purposes . Corresponding to this situation, Skl.U / III contacted the RLM and the company FLETTNER again about the delivery of helicopters as soon as possible. It turned out that in the meantime the army is also showing great interest in the FLETTNER helicopter, primarily for pioneering purposes. The interest of the Army Weapons Office even went so far that the company was promised 40 skilled workers for faster further development. It is to be feared that the FLETTNER works will be forced to work primarily for the army. Such a procedure would be all the more disadvantageous for the Navy, because the helicopter could not only be used for anti-submarine purposes, but also as a general on-board reconnaissance. The reasons that make the Fl 282 appear particularly suitable as an on-board reconnaissance aircraft are as follows: 1) The aircraft takes up the smallest possible amount of space. With the rotor blades removed, the Type 282 has a fuselage length of 6.56 m and a width including landing gear of 2.40 m. By staggered installation, 10 helicopters can be set up in the same space that is required by a normal on-board aircraft. 2) Getting started can be done in a few minutes. The very handy little aircraft is easy to get out of the hangar on the ship, the rotor blades are mounted in a very short time. Movements of the ship bring only the slightest impairment for the preparation of the start. 3) The rotor engine can already run at full speed at the Haltetau. By releasing the rope, the helicopter jumps up from the deck in one set (jump start). 4) After take-off, the helicopter can, if necessary, climb vertically up to m. It flies 60 km / h at economic speed, 120 km / h at high speed and 150 km / h at top speed, but this is uneconomical. The flight duration is 1.5 to 3 hours, depending on the speed. Page 28

29 5) Observation from the helicopter is extremely beneficial, as it can stand in the air and turn in all directions. 6) If the engine fails, the rotor blades automatically switch to autorotation, i.e. gliding flight, which enables the pilot to jump with the parachute if necessary. 7) Landing on the stern of the ship takes place in such a way that a landing rope is dropped from a height of about 10 m above deck, which is then pulled taut by hand on deck over a pulley. This holding on ensures that the helicopter takes part in exactly the same up and down movements of the ship. This means that it can be taken down on deck without the risk of damage.8) The storm safety, which has already been proven on various occasions, and complete independence from sea conditions, together with the larger number of helicopters that can be accommodated on deck, make it possible to secure the ship through continuous aerial observation, regardless of wind and sea conditions . How much better aerial reconnaissance could be achieved with the use of helicopters instead of normal on-board aircraft can be seen from the fact that ADMIRAL SCHEER was only able to use his on-board aircraft on 28 days at sea on his last 180-day sea trip. If the abovementioned advantages of the helicopter are recognized, it appears necessary to take all measures immediately in order to obtain the most comprehensive possible equipment for the underground fighters and also other surface vehicles with helicopters in a short time. The prospects of achieving this are extremely slim given the current worker situation and the low level of urgency of the FLETTNER works. At the same time, in order to be able to meet the planned delivery times for the Fl 282, the FLETTNER company demanded 50 qualified engineers and technicians for the technical office and 200 skilled workers for the workshop. In addition, in July 1941, all of the extensions were to be started and the funds to be invested by the RLM were to be made available. The following paragraph is noteworthy in the above-mentioned letter: Skl.U / III is currently also in negotiations with the FLETTNER company about the project of a helicopter for large submarines. In contrast to the previous and future plans, the helicopter intended for these submarines should have the shape of an upright cylinder. It will be housed in a pressure-tight container behind the submarine tower. For stowing, it is only necessary to lower it into the container by means of an elevator and to accommodate the folding rotor blades. This submarine helicopter would be able to climb to m, but only reach a speed of 50 to 60 km / h, which would be sufficient for the needs of the submarine. The development of this type of helicopter appears particularly important. [22] The Naval War Command correctly assessed the situation in the air force armaments sector in its letter dated: The desire to advance and accelerate the technical production of the helicopter is offset by the need to work primarily with the industrial capacity of the air force . There is no doubt that the Luftwaffe is unable, given the current war situation, to free manpower for the construction of aircraft that are unable to make a significant contribution to the decision to go to war. Even the Navy is not able to hand over skilled workers to the FLETTNER company to promote the construction of helicopters. The Skl. therefore does not see itself in a position to make the demand for a higher urgency classification of the helicopters in the armaments program of the air force. However, she will the Ob.d.L. ask to support the construction of the FLETTNER helicopter within the scope of the possibilities and to take over the production of the helicopter types in the highest urgency level SS. [23] It would go too far to quote further Skl. Files on the subject of Fl 282 at this point. The above statements already show how much the Navy, in contrast to the Air Force, advocated the faster development and series production of the Fl 282 to equip its ships. However, all efforts should be unsuccessful. Even in mid-1944, when the further construction of all helicopters and gyroscopes had already been stopped by the RLM and the helicopter affair had come to an end due to the dissolution of 3./196, the naval war command put the R.d.L.u.Ob.d.L. and GL / CE 2 with date of still the study: Tactical-technical requirements for helicopter aircraft for use over sea, in which the following development patterns were referred to: a) FA 223, land-based, for escort security, anti-submarine control and guidance of U-Jagdverband, b) FA 223 Zwilling (development of the dachshund and crab), land-based for special transports, as a torpedo carrier (flying speedboat) and as an anti-aircraft carrier (with at least a 2 cm quadruple flak) for escort security, c) Fl 339, on-board, as an auxiliary aircraft alongside the Ar 196 and as a command aircraft for submarine fighter units in the offshore area. All samples should be equipped with a ship search device (range approx. 10 km). Page 29

30 From August 1942, the first deck landing attempts with Fl 282 took place in the Lübeck Bay on the air traffic control ship GREIF of the E -stelle Travemünde. A wooden platform, which was firmly anchored on the flat stern of the GREIF, served as the landing and take-off point. The machines Fl 282 V5, GF + YE, and V6, GF + YF were used. In the middle picture you can see the V5, in the picture below it is the V6. In the picture above, the exact identity cannot be made out. Page 30

31