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The history of aviation is synonymous with the experiences of those men and women who, through their work as designers or pilots, made its development possible in the first place. Many have become virtually immortal through their deeds in war and peace, sometimes through an exaggerated cult of heroism. Some, despite their achievements, have disappeared into the darkness of oblivion. One could describe Gottlob Espenlaub as a tightrope walker, whose ingeniously simple Instructions next to his stories faded. To report on the career of his brother Espenlaub became a decision to write a book. However, there is not enough space for that - therefore, only the essentials are mentioned here.
At the beginning of July 1920, Gottlob Espenlaub received the most important letter of his life - something he couldn't have known at the time! He had applied for an advertisement seeking volunteer helpers for the first Rhön Gliding Competition in mid-July 1920. Carpenters and locksmiths were preferred, which suited Gottlob perfectly, as he had previously lost his position as a journeyman carpenter. Oskar Ursinus, the publisher of the magazine "Flugsport" and initiator of the Rhön competition,
in his letter of July 3rd, Gottlob Espenlaub requested that he arrive in Gersfeld/Wasserkuppe no later than the evening of July 9th.
This decision would never be regretted by the not-yet-20-year-old.
In the years from 1920 to 1923, Gottlob Espenlaub developed from a clever carpenter, of whom it was said on the Rhön that he could repair a break overnight, into a successful and envied aircraft designer and glider pilot. Without ever having heard of the necessary calculations, he secretly built a small hang glider from the debris of the first Rhön competition, but it quickly broke. Afterwards, he met Alexander Lippisch, who years later would become a design genius in glider construction. Together they built a tailless hang glider, the E 2. Both were then known as the "Rhön Indians" due to their living conditions in their homes.
The third Rhön competition in 1922 brought Gottlob the long-awaited success. He brought his E 3 to the competition, a “freehand” designed shoulder-wing glider with a then-gigantic 17-meter wingspan, and cantilevered! This had never been done before. While academics and engineers struggled to create something useful for the gliding movement, a simple carpenter's apprentice achieved something almost impossible. The spell was broken, and from then on, “Espe” was a household name.
A year later, he built the E 4. a 15-meter glider, which already had a fully planked fuselage. Also in 1923, the E5 was built, with which he finally learned to fly himself and with which he successfully participated in various events.
In the winter of 1923/24, Espe accepted an invitation to Grunau. The Silesian group of the German aviation association wanted to generously support him if he decided to relocate, with which he fully agreed. In Grunau, in addition to a small number of his most successful type to date, The E 5 was also a training glider (presumably designated as the E 6), which is considered an ancestor of the SG38, built in the thousands. In 1924, Gottlob's brother Hans, two years younger, joined him and would become his most loyal collaborator in the following years. For the Rhön competition in August 1924, which included a special competition for gliders with auxiliary engines, the Espenlaub brothers built their first motorized light aircraft, which was nothing more than a converted E 5 with a Douglas engine. Although the E 5 (motorized) is listed in the entry list, it did not appear at the starting line. Instead, Gottlob flew his E 5 as a glider in the competition. The successes of the other participating small aircraft  such as Bäumer's "Rote Vogel" - had impressed him. In the coming months, his E 5 was fitted with the finally delivered Douglas engine and prepared for the next flying season in 1925. But that wasn't all: The Espenlaub brothers built a second E 5, which was fitted with a Victoria engine. The decision to participate with it in the coastal gliding competition in Rossitten in April 1925 was quickly made. In the entry list, his two aircraft were designated EM 1 and EM 1a (Espenlaub engine 1 and 1a). During the competition, however, they were presented with their final numbers, E 7 and E 7a. The initial disappointment over the Douglas E 7 engine not being able to be started was made up for by several successful flights of his E 7a (Victoria). Accordingly, the jury rewarded his performance with a total of 1,055 marks.
After the Rhön competition, Gottlob ended the 1925 flying season with his participation in the Crimea expedition in September. Afterwards, another move was in order. Kassel was to become the new place of work for the creative brothers, who spent the winter of 1925/26 there. established. In March 1926, Gottlob parted with his E 7a and sold it to Norway. Since the never-flown E7 (Douglas engine) was presumably converted back to its original E 5 (glider) configuration, they were now without a powered aircraft. The following model, the E 8, was intended to remedy this. However, the move had consumed so much money that the purchase of a new Victoria engine had to be postponed. To replenish their funds, Gottlob and Hans organized several flying days on their own. They also came up with something special for the 1926 Rhön competition. The E 9, with its gigantic 24-meter wingspan, was to be the star of the event. Unfortunately, Gottlob ended his performance with an or- The E 9 was in serious trouble. The E 10 glider, which was also brought to the competition, was a further development of his old E 5.
But Gottlob no longer had much fun with gliders. The Rhön events had reached a dead end. The academic flying groups, whose innovations had guaranteed progress for years, were growing weary. The trend was shifting back towards powered flight. Gottlob and Hans could not escape this trend. In late autumn 1926, the two of them started working on the E 8 again. The 500cc Victoria engine was procured and installed. The E 8 was created as a glider with an auxiliary engine – a concept that had been developed in principle in 1924 and 1925. It was a matter of time. Meanwhile, Gottlob actually had something else in mind – a proper motorized aircraft with several horsepower. So the E 8 was mothballed again. In the winter of 1926/27, his E 11 was finally built, powered by a 35 hp Anzani radial engine (this aircraft will be featured in a documentary in a later issue of MFI). For Gottlob Espenlaub, the year 1927 began with a new adventure. Gerhard Fieseler, then a flight instructor with the Kassel-based Raab-Katzenstein company, contacted the Espenlaubs at the beginning of March to charter a glider from them. Fieseler had already approached Max Kegel with the idea of ​​a glider towed by a motorized aircraft to retrieve his record-breaking aircraft from the  to use the previous year's Rhön. But Kegel declined out of concern for his aircraft. Gottlob, on the other hand, had always been open to unusual ideas. He didn't have to think about it for long, as his E8 seemed to be a suitable aircraft. The tow coupling devised by Fieseler was mounted, the unneeded propeller was removed, and the experiment could begin.
On March 12th, the time had come. At Kassel-Waldau airfield, the Espenlaubs met with their E 8 as a tow plane, along with Fieseler in the RaKa RK 6 D-975. Gottlob must have suddenly had second thoughts, because he released the tow rope too early each time during the three tow flights, so that at most, it resulted in straight flight. Despite everything: This day had proven that aircraft towing was practically feasible. Antonius Raab, who had initially viewed the whole matter with great skepticism, suddenly sensed an opportunity. Now he took charge of the project. In a letter from RaKa Works to Espenlaub dated March 14, Raab summarized his thoughts once more: "For the purpose of trials launching a glider using a powered aircraft, you will make your aircraft E 7 available. You will remove the engine from your aircraft and configure the machine so that it can fly as a glider without the engine." . The execution is your ( matter. A total of up to six flights with 1 your machine in tow will be carried out for test purposes. The tests carried out on Saturday the 12th are considered a test flight. Why Gottlob Espenlaub had once again designated this aircraft E 7 will always remain a mystery. The fact is that the motorized E8 and the E 7, which became known as a trailer, are identical. Just under a week later, on March 20th, Raab was already planning a demonstration for the press and film crew. Gottlob and Hans didn't have much time to remove the engine and lengthen the nose due to the shifted center of gravity. Thus, the single-seater E 8 became the two-seater E 7! Gottlob had his red-painted aircraft with the white lettering "Espenlaub" (Aspen Leaf) and therefore got into a heated argument with Raab, who wanted to see the publicity on his side. Raab's "instructions" also ultimately led to the press giving their full attention to the lively Gottlob. In the newsreel, the names Raab or Fieseler were therefore not even mentioned. When the tow, consisting of the E 7 and the RK 6 (an LVG B III replica) D-975, was ready for takeoff, no one suspected how short this spectacle would be: Already during the takeoff process, at a height of about 15 meters, the rudder of the E 7 broke.
That was it! Raab had had enough and terminated the agreement with Gottlob, leaving him owing the outstanding balance of 100 marks.
The RaKa works then constructed their own tow trailer within a few weeks, with which they caused a sensation at the airshows of the coming season. Gottlob also liked the idea of ​​his own tow vehicle. With his E 11, he had a correspondingly powerful tow plane, and the E 7 remained what it was – a “trailer aircraft.” Raab, in turn, could not let that stand and sued Gottlob Espenlaub for an injunction, since RaKa had the sole right to use the tow flight. The initial injunction against Espenlaub was, however, declared invalid by the Kassel Regional Court on May 31, 1927. This triggered a dispute between Antonius Raab and Espenlaub that would not be resolved until the early 1980s.
The Espenlaub brothers had other concerns at that time. They moved again, this time to Düsseldorf-Lohausen. Here, for the first time, they had the opportunity to establish a small business on sufficient space and to further develop their...fold. The Espenlaub tow train was first demonstrated during the coastal gliding competition in Rossitten at the beginning of May 1927. Since Hans Espenlaub was tasked with moving to Düsseldorf and Gottlob did not possess a powered aircraft pilot's license, he had to hire two outside pilots. Edgar Dittmar (the older brother of the well-known Heini Dittmar) was in the E 7, and the E 11 was piloted by the former fighter pilot Willi Mejo from Essen-Kray. Although various problems arose again, the basic principle remained. Since the two-seater E7 could not be convincing due to its provisional nature, Gottlob designed a new, lighter glider, the "Espenlaub Trailer 1" (EA 1). This enabled him to perform successful demonstrations at the airshows of the next two years. The E 7 was mothballed once again and only brought out again in 1929 for the infamous rocket flight tests in Düsseldorf-Lohausen.
So much for the subject of the Espenlaub E7 glider trailer.
One of the next issues will report on the E11 motor aircraft, the Espenlaub tow plane, and the rocket tests with the E 7. As Marton Szigeti already described, the Swabian Gottlob Espenlaub from Balzholz had never studied aircraft construction, nor belonged to any academic flying club – he was self-taught. Obsessed from aviation, he simply had to build airplanes! His trained carpentry skills were certainly an advantage, but that alone wouldn't have been enough. Espenlaub was a gifted tinkerer with the ability and the courage to build airplanes, while other designers were still hesitant about the idea or even considered it completely hopeless. Shaped by his years on the Wasserkuppe and his collaboration with Lippisch, he designed and built several machines—Marton Szigetti will discuss these in more detail in the second part—that astonished the experts. To make it even clearer, let's compare "Espenlaub" to a model maker who sees a colleague's model; While he had meticulously built his machine according to calculations and excellent plans, Espenlaub could have rebuilt the model without plans or calculations in a fraction of the time, and probably even simplified and improved it. From the E4 onward, with its spindle-shaped fuselage and three-part wing, Espenlaub had designed a concept for gliders and powered aircraft from which he did not deviate for a long time. This made the drawing easier for me. The reconstruction process was significantly easier; besides the photos and descriptions of the E 7 and E 8, I was also able to refer back to earlier designs to reconstruct some of the design principles graphically.
Of course, I cannot and do not want to claim that the trailer and rocket aircraft that was reconstructed was actually built in every detail exactly the same way back then, and that the calculated dimensions are accurate down to the millimeter. This is impossible, even if further photographic material had been available. The development of this reconstruction would be a story in itself, and I confess that there were moments when I doubted my sanity, how I could ever have promised Marton Szigeti that I would create a drawing of this machine. At the same time, there was the thought that without a drawing, hardly any model builder could recreate this Espenlaub type - and, of course, the fact that
I am an absolute Espenlaub fan. This cult goes so far that my wife bought me a pea sausage, which has been waiting for some time now to be eaten;
and anyone who knows anything about the "Rhörv Indian" period on the Wasserkuppe knows the significance of the pea sausage...! But back to the Espenlaub E 7. The fuselage, wing, and tail assembly of the E 7 and E 8 are identical; minor changes were only made later to the E 7 rocket plane, but these are in small details and are minimal.
Before I get to the technical description of the trailer-type aircraft Regarding the E 7 (today such an aircraft was described as a two-seater glider with a tow coupling), I would like to thank Joachim Ewald; I asked him for advice on various details. As usual, he listened patiently and gave me tips and advice – thank you, Cassius!

Technical Description
Fuselage: Spindle-shaped longitudinal section with oval cross-sections. Superstructure made of frames and stringers with complete plywood planking. The nose of the fuselage was probably made of sheet metal with crimped edges – the strong curves would be visible in the photos with a wooden construction, despite painting, due to the many necessary scarf joints, which is not the case. One can also assume that Espenlaub and his brother Hans certainly didn't spend ages filling and sanding to bring the nose of the fuselage to this clean state. They simply didn't have the time or the money for that. The main fuselage frame also serves to support the triangular front canopy struts for the wing mounting. A central canopy on the upper fuselage behind the rear seat – the pilot's seat in the E 8 – serves as a third strut and bearing for the wing. Despite all considerations, the second triangular strut on the right side of the fuselage next to the main strut remains inexplicable. It was not present in the E 8, so it cannot have served as a cover for the aileron control cables or for similar purposes. A dear friend, who never flies without a camera attached to the aircraft, jokingly suggested that it must be a camera mount. The "strut" could hardly have served for stiffening, as its thickness is so minimal that it would not have withstood either compressive or tensile forces. For what purpose this part was useful will probably remain a mystery. The main fuselage bulkhead also serves to support the triangular, forward canopy struts for the wing support. A central canopy on the upper fuselage behind the rear seat – the pilot's seat in the E 8 – serves as a third strut and supports the wing. Despite all considerations, the second triangular strut on the right side of the fuselage next to the main strut remains inexplicable. It was not present in the E 8, so it cannot have served as a cover for the aileron control cables or for similar purposes. A dear friend, who never flies without a camera on the aircraft, jokingly remarked... that this must surely be a camera mount... The "strut" could hardly have served for stiffening, because its thickness is so minimal that it would not have withstood either compressive or tensile forces. What purpose this part served will probably remain a mystery. Even in the E 8, the pilot's head protruded slightly into the gap between the two wing root fairings, which was unlined in this area. This was also the case in the E 7; however, the passenger now sat there – the pilot's cockpit was now located in front of the wing, which was essential for center of gravity reasons. After all, the weight of the no longer present engine had to be replaced. The cockpit openings are narrow; the passenger must have contorted themselves considerably to get into their seat. This was not uncommon at the time; comfortable entry and exit were unheard of! The cockpit openings were padded with leatherette; whether this was to protect the plywood or the pilot is unclear! Nothing is known about the instrumentation. An altimeter and speedometer, perhaps also a compass. That was certainly all that was available The landing gear was also mounted on the main bulkhead, presumably sprung by rubber bands. The axle had a relatively thick, teardrop-shaped fairing made of plywood. In the rocket version, the rear seat cutout was sealed with a plywood cover; otherwise, the fuselage of this version is completely identical to that of the glider version, except for the missing tow hook. This also applies to the entire aircraft, except for special fairings to protect the airframe from rocket exhaust and fire hazards.
Wing: Two-piece wing with a sheeted torsion leading edge up to the main spar. Rectangular main rib up to the aileron, slight tail sweep from rib 2 onwards; So,
the profile at the root is approximately 1.56 meters deep and then tapers down to a depth of 1.40 meters from rib 2. From the aileron onwards, the wing is slightly trapezoidal. The aileron has a very large aerodynamic balance that extends over two rib sections. It has a simple triple bearing and is driven by steel cables. An auxiliary spar is mounted on the main spar from rib 3 onwards. It runs at an angle of approximately 45 degrees to the rear and forms the connection point on the central fuselage canopy behind the passenger compartment. The two wing halves are covered with narrow plywood strips at the root ribs, and a metal or plywood covering closes the wing gap. In the rocket version, there were various versions of small, narrow extensions behind the trailing edge, presumably to protect the upper fuselage from burns.
The airfoil used is unknown; the thickness must have been slightly over 25 cm. The ribs almost certainly had a spacing of 40 cm each, and intermediate ribs were attached in front of the main spar. The rib construction could not be photographically documented, but they were certainly web-type ribs. Also undocumented is...The fact that the covering in front of the main spar was made of "real" plywood or only some kind of veneer wood was used – this was the case with the wing of the Espenlaub 4. This would also explain why there were so many bumps in the area of ​​the leading edge. The wing was covered with the silver celluloid covering common until the 1950s.
Tail plane : Vertical and horizontal stabilizer without a damping fin, i.e., pure all-moving stabilizers. Vertical stabilizer spar-rib construction. No covering. The main spar/strap also serves to support the pivot axis of the stabilizer. A circular cover behind the bearing on the upper fuselage rear provides access to the control cables for the vertical stabilizer. The all-moving horizontal stabilizer, like the vertical stabilizer, has a rectangular planform; its structure consists of stringers and formers, and a box spar spanning four rib bays provides somewhat greater torsional stiffness. Otherwise, there is no plywood or laminated covering. The pivot point and bearing of the horizontal stabilizer are located precisely at the end of the fuselage tube. The drive mechanism of the horizontal stabilizer is... The tail assembly is actuated via a pushrod. All tail assembly parts are covered with silver celluloid.
Landing gear: Bipedal landing gear with two fabric-covered spoked wheels. The landing gear axle is mounted on the main bulkhead, and the suspension is provided by rubber bands. The landing gear axle is covered outside the fuselage by teardrop-shaped fairings. A steel spring strut is located at the rear.
Towing coupling: At least three different designs on the nose of the fuselage and one version with a ring around the cockpit and the towing coupling located there. The coupling is operated by a cable that is guided once by a pulley on the top of the nose of the fuselage, has another guide just in front of the pilot's seat, and is operated from there by the pilot. Our drawing shows the coupling as shown in the photo. On the "Espe", pilot Dittmar attaches the tow rope. The coupling was removed from the rocket aircraft.

Paintwork: Fuselage red over all-
lés, kite mouth on a yellow background at the nose. The upper part of the nose cone has a yellow decorative marking. All decorations are mirrored on the left and right, including the "eye" between the dragon's mouth and the leading edge of the cockpit cutout. The inscription "Espenlaub" (Aspen Leaf) in white is on the left and right of the tail boom. The inscription "Espenlaub 7" is black on both sides of the rudder.
The leading edge of the wing is painted red across the entire wingspan, up to the main spar.
All covered parts are unpainted; the gray color results from the silver celluloid covering. The tow coupling, made of steel tubing, is left in its natural metal state.
The rocket plane has an identical paint scheme. After the vertical stabilizer caught fire during the first tests, part of the tail assembly was covered with a sheet steel fairing; it is probably left in its natural metal state. The inscription
"Espenlaub 7" is no longer present.
Note: The exact shade of red can no longer be determined due to incomplete records, nor can the color of the decorations; other colors besides yellow are also possible.
Unfortunately, nothing more precise could be determined.

THE ROAD TO THE GLIDER TOWPLANE ESPENLAUB E7

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