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Work on the aircraft, designed by Franz Xaver Mehr, began in the winter of 1931/1932 in his small company in Meckenbeuren, known as Flugzeugbau Friedrichshafen Mehr & von Rüdiger GmbH, and was completed in March. The drive was a car engine from 1929 converted by the DKW works in Zschopau, which was tested and approved by the DVL. The first flight of the prototype, initially called Friedrichshafen Me 5, was carried out by Alfons Lüber in mid-July 1932 from the Konstanz airfield without any complications. The further flights did not cause any problems either, and so the test was completed on August 16 with a four-and-a-half-hour continuous flight at an altitude of 2000 m. In search of a financier for the planned production, Franz Xaver Mehr then transported the Me 5 with the wings attached to a car by road transport to Zschopau and flew it to the owner of the DKW motorcycle factory there, Jørgen Skafte Rasmussen. Rasmussen expressed himself positively and decided to start series production at the Erla ironworks. Material procurement began in 1932 and at the beginning of May 1933 a second example was issued, designated Me 5 a, which had a height reduced by 15 cm and a top speed increased to 120 km/h. This was intended as a prototype aircraft of a small series comprising a total of eleven pieces and was therefore to be flown publicly at the "NSDAP Major Flight Day" on 25 June 1933 in Dresden with the hope of subsequent construction contracts. However, since approval had not been granted by this time, the prototype had to be used. In the meantime, it had been registered as Erla Me 5 a at about the beginning of 1933, had received the registration number D-2378,[2] and in April 1934 had again been transported by road to Erla, where it had been equipped with a DKW engine of 20 hp for presentation flights. The demonstration turned out to be extremely unfavorable due to engine problems and ultimately had to be stopped completely. The testing and acceptance of the second aircraft was also delayed by problems with the engine, among other things. It was finally registered in September 1933 as D–2585. [3] In the meantime, construction of the remaining ten Me 5 a had started in July, but was slow due to the lack of engines, and sales also fell short of expectations. By the end of 1938, however, all eleven production aircraft had been sold. One of these aircraft survived the Second World War, flew in Germany from 1955 to 1958 and then made its way to Switzerland, where it received a new engine and flew for the first time in October 1967. It has been preserved and is at home at the Birrfeld airfield in an airworthy condition. [4]

From 1937 onwards, Franz Xaver Mehr developed the Erla 5D with an enlarged rudder, modified landing gear and Zündapp engine in response to a demand from the NSFK for a single-seater training aircraft with a 50 hp engine from the Me 5 a. The prototype was completed in June 1938 and publicly exhibited at the Belgrade Air Show in July, but this did not result in any orders. Instead, the only example registered as D–YMOP with the pilot Friedrich Auermann completed a three-continent flight from Europe via Asia to Africa and back from 1 April to 20 May 1939, covering around 20,000 km. For this purpose, it had additional tanks in the fuselage and wings , which increased the total volume to 140 l (101 kg) and increased the range to 1500 km. [5] It was then presented at the Aerosalon in Brussels in June 1939, again without success. Shortly afterwards, Heinz Gabler set a long-distance world record of 1915 km in its class on the Friedrichshafen–Vännäs route with the Erla 5D from 2 to 3 August 1939. The aircraft had been given a closed cabin for this flight. It was then added to the German Aviation Collection in Berlin, where its trace is lost in the turmoil of the war.

The Erla 5 is a self-supporting low-wing aircraft in all-wood construction. The fuselage as well as the supporting structure with 2.14° sweep consist of a plywood-planked wooden construction partly covered with fabric. The wings are designed to be folded against the fuselage, which makes it possible to transport the aircraft on the road attached to a car or motorcycle. The rudders of the cantilevered tail are covered with fabric, the elevator and side fin are planked with plywood. The production aircraft differ from each other in slightly modified landing gear and, in contrast to the first prototype, do not have main wheels connected to an axle. The Erla 5D has a main landing gear with a track width of 1.25 m and 380 × 150 mm low-pressure tires, while balloon tires are also used in other examples.

Erla Maschinen werk G. m, b. H, is represented by two original aircraft, of which the single-seater
Erla 5 D training and sports aircraft is equipped with the new four-cylinder in-line engine developed by Zündapp.
Cantilever low-deck yield in timber construction. A 2 m wide middle section, firmly attached to the fuselage, and two attachment wings. Connection by 3 bolts each. A
main and an auxiliary spar made of pine straps and plywood bars. Ailerons hinged on the auxiliary spar, plywood planking on the outer wing to the front spar, on the
middle piece to the rear spar.
Square hull with domed top, 11 frames made of spruce and plywood. Removable engine stem made of sheet steel. Behind the open driver's seat is a
luggage compartment. Plywood planking. Cantilever wooden stabilizer, elevator fin mounted in front of the vertical stabilizer on the top of the fuselage.
Fixed chassis with low-pressure tyres (380 X 150 mm). The axle halves, which are hinged on a pyramid made of four steel tubes under the fuselage, are guided in
a V-strut and cushioned with rubber struts.
Engine: Air-cooled Zündapp in-line engine with four overhead cylinders. Continuous power 40 hp. Three-part cladding made of electron sheet, fuel stock older from 40
1 content immediately behind the fire bulkhead, conveyed by a motor-driven DBU pump.
Wingspan lim, length 6.4 m, area 13.7 m2, curb weight 240 kg, flying weight 360 kg, wing load 26.3 kg/hp, power load at 46 hp maximum engine power
7.8 kg/hp, top speed 154 km/h, cruising speed. 132 km/h, landing speed 60 km/h, ascent time at 1000 m 6.2 min, at 2000 m 15.2 min,
practical summit altitude 4700 m, range 400 km, fuel consumption 101/100 km. In addition to this low-wing aircraft, which was developed from the Erla 5a model, which was previously equipped with the water-cooled DKW engine

To prove the versatility of its intended as a "Volksflugzeuge" small aircraft, 1937 was installed in an Erla engine, the new water-cooled four-cylinder in-line type Zündapp Z9-092 with 2 liters and 50 hp starting power. The now called Erla Me 5D aircraft was extended to 6.80 m. The only machine was finished in June 1938 and was presented to the public for the first time with the registration number D-YMOP at the Belgrade Air Show one month later. On 1 April 1939, Erla factory pilot Friedrich (Fritz) Aufermann and D-YMOP started at the airport Berlin-Tempelhof for the "Europe-Africa-Asia-Europe-Flight" over three continents and came on 20 May for a distance of 20,000 Kilometers to the destination Leipzig. In class C, 4th category (up to 2 liters displacement), factory pilot Heinz Gabler set a new long-distance record on August 2, 1939, when he was with D-YMOP, which now had a closed cockpit, without a stopover from Friedrichshafen on Lake Constance over 1915 kilometers to Vännäs in Sweden flew.
The economic success remained, however, and so few Erla Me 5 were built as a school aircraft.