Lajos Rotter's interest in aviation became apparent in his secondary school years, when he built elaborate aeromodels and spent his summer vacations at aircraft factories as apprentice. His secondary school graduation coincided with the end of the Great War. After the war he was enrolled in the mechanical engineering faculty of the Technical University of Budapest. During his years at the university he studied wide aspects of aviation utilizing his command of four languages. He was one of the originators of the Technical University’s Sportflying Association (MSrE) in 1921. Even as a student he published articles in different scientific aviation reviews. His first book „Vitorlázórepülés” (Gliding) was published by the Hungarian Aero Association. When the Ministry of Transportation’s Aviation Department had invited glider designs in a frame of a design contest in 1922, Rotter together with a fellow student István Ágotay presented a design. The design was accepted. Its construction had been started at a woodwork factory, however it was never finished as the previously promised financial help did not materialized.
In 1923 the Orell Füssli Institut in Zürich invited scientific papers on helicopter design. Rotter’s paper and design won the contest. Rotter graduated from the Technical University in 1923.
At the same year, even before his graduation from the university, an aircraft factory, the FEIRO, had been set up by him and two brothers, Gyula and László Feigl, Rotter serving as technical director and chief designer. Their aim was to develop passenger aircraft for the growing local market. Three types were designed and built: FEIRO-I.jpg (4 passengers, 120 Hp Le Rhone engine) and FEIRO Daru (4 passengers, 180 HP Hispano engine) passenger aircraft, and FEIRO Dongó (2 persons, 100 HP Gnome Oberursel engine) trainer. Unfortunately the country’s financial and political decision makers did not see the potential in a Hungarian designed aircraft and finally the factory dissolved.
From this time onwards his life had two spheres of action: his professional life and his gliding activity. In the first his engineering talents earned him different leading positions in Hungarian industry – aviation and non aviation related sectors as well. He was an excellent designer and his path was marked with patents in every field where he worked. His gliding activity encompassed designing gliders, flying gliders, serving as gliding instructor, serving on different gliding committees at home and abroad, and in general promoting and supporting Hungarian gliding.
Following his gliding related activity he prepared a new glider design in 1927, however it was never built due to lack of financial as well as moral support.
When in 1929 the Flying Section of Hungarian Nation Home Guard (MOVERO) was formed in Farkashegy - the first gliding field in Hungary in the vicinity of Budapest - and gliding finally started, Rotter was present as one of the leading technical experts.
Realizing that without actual flying experience he might not become a good designer and technical expert he earned his pilot license for power planes in 1930 and in 1931 his competence to carry passengers. He started gliding in 1929 at Farkashegy and in 1931 he earned his C badge there.
He was elected into the Hungarian Aero Association as a member of the governing committee in 1928. He served as the top technical expert for the Association.
When in 1930 the ISTUS (Internationale Studienkommission für den motorlosen Flug – International Commission to study motorless flight) was founded he was elected as a member of its scientific committee.
In the mean time he and Frigyes Hefty Sr., another great personality of Hungarian gliding and a experienced former WWI fighter pilot, purposefully walked around in the hills west of Budapest studying the hill formations to find a site suitable for ridge gliding for all dominant wind directions and which have acceptable landing areas around. They discovered Hármashatárhegy (Hármashatár mountain) as a suitable gliding site for dominant SW, W, NW and NE winds with good bungee cord launch points, good landing fields and gentle slopes for basic training flights.
At the spring of 1933 Rotter got an assignment from the Hungarian Association of Boy Scouts to design a glider which would represent Hungary at the Boy Scouts’ World Jamboree at Gödöllő (a village east of Budapest). The result of this assignment was the Karakán. The Karakán first flew at August 4, 1933, with Frigyes Hefty Sr. at the controls. Next day Rotter performed a 1 hour 2 minutes flight at Gödöllő. At August 6 he made a 68 km distance flight. Two days later he achieved a new Hungarian distance record of 84,8 km and a new Hungarian altitude gain record of 1840 m.
Just before the Jamboree Rotter organized Air Scouts, the Gliding Section of the Hungarian Boy Scouts’ Association. After the Jamboree the wooden hangar built at Gödöllő for the Jamboree was moved to Hámashatárhegy and re-erected there by the Air Scouts. At first Rotter’s proposal to open up the new gliding field had not been accepted by the authorities declaring the site dangerous. However after his successful 1 hour flight in 1933 – then necessary to prove that a new site is suitable for gliding - the new gliding field was finally accepted officially. The hangar of the Air Scouts was opened at January 6, 1934.
At February, 1934 Rotter won the first Hungarian Silver C badge, ISTUS number 19, flying the last leg of the badge: 5 hours 3 minutes over Hármashatárhegy. In the same year at October 07-08 he flew the Karakán over the NE slope of the mountain for 24 hours and 14 minutes setting a new Hungarian duration record. Next year he set a new Hungarian distance record of 274,8 km with Karakán winning a complete instrument panel offered by professor Georgii for the most successful distance flying Hungarian glider pilot. The Karakán was the first Hungarian glider fitted with instruments.
His next glider design – a joint work with Zoltán Janka - was a single seat training glider named as Vándor which was qualified for basic aerobatic flights as well. The Vándor was built at Gyöngyös and at first was used there. Later she was moved to Gödöllő to the Ikarus Gliding School specialized for winch launching. Here the first Hungarian car-tow launch was executed with this glider.
In 1935 at the conference of ISTUS held in Berlin Hungary was represented by Rotter. He presented a paper at the conference about Hungarian gliding, Hungarian glider designs as well as gliding experiences and results. His presentation was illustrated with stills. In his presentation he gave account of his observations on rotor clouds on the lee side of mountains considering the possibilities to climb in gliders utilizing the lift in the upward side of rotors. His presentation was so successful that the conference decided to hold the next conference in Budapest next year. Rotter proposed to organize a glider competition for this occasion which was accepted.
The ISTUS Conference was held at Budapest between May 18 and 24, 1936, and the competition was held at Mátyásföld airfield at the same time. The German Heini Dittmar won the altitude gain event by 1800 m, flying a Rhönsperber, the Hungarian Béla Sipos-Szabó won the duration flight event by 7 hours 9 minutes, flying a Grünau Baby, and Lajos Rotter won the distance flight event by 138,9 km flying his Karakán.
1936 was the year of the Olympics. Berlin hosted the games for which the International Council of Olympics (IOC) had previously accepted gliding as a demonstration discipline. The Hungarian Aero Association convinced by Rotter’s results asked him in early January to design a new high performance glider which would represent Hungary at the Olympics. Rotter accepted the challenge and started to design the new glider, Nemere, immediately. Béla Samu, who later became one of the top aircraft designers of Hungary, helped him with the calculations and drawings. The glider was built at the Hungarian Repair Works at Székesfehérvár, a town south-west of Budapest, and had two short test flights at July 25,1936, with Rotter at the controls before she was shipped to Berlin. As glider instruments were scarce at those times in Hungary the Karakán was robbed to get Nemere be fitted with instruments.
The training flights of German and foreign pilots representing their countries were performed at Rangsdorf Field, and the demonstration flight were held at Staaken Flying Field at August 4. After the demonstration flights were over Rotter declared at the evening of August 10 at Rangsdorf, that next day he would fly to Kiel, where Olympic sailing events were held. His declaration was received with skepticism as the forecast predicted poor gliding weather. Next day, launched by aerotow at 12:26 and releasing at 12:38, he performed the remarkable feat of piloting Nemere to Kiel in quite a poor weather. Arriving over Kiel at an altitude of 650 m he saluted the Olympic site with two loops and landed at the military airfield of Holtenau at 16:55. The distance he flew was 336,5 km. This was the longest pre-declared goal flight by a sailplane, and the longest distance flight made by a glider during the whole year of 1936. He used a flying technique later called “dolphin flying” utilizing the flaperons system of Nemere.
Next year – in 1937 - the highest honor in gliding, the golden ring of ISTUS, was awarded to Rotter by the ISTUS conference held in Salzburg. This honor was awarded for outstanding performances in promoting gliding, outstanding results in scientific fields related to gliding, and internationally outstanding performances in actual gliding. Only three persons earned this ring on the whole world and Rotter was the first who got it. The same year Rotter was elected into the FAI’s committee of pilots. Every year one pilot with an internationally outstanding gliding performance in a glider of his own design was elected to this Committee.
Subsequently the IOC’s meeting held at Bern at March 24, 1938, where the Council included gliding into the list of optional Olympic summer sports for future Olympic Games, a decision was reached by FAI that all participants have to fly a common glider type the main characteristics of which were defined. Designs had been invited in the frame of a design contest and the final selection on the type was done by testing the prototypes of the entered and accepted designs at Sezze airfield in Italy between February 20 and 26. Rotter was selected into the group of six evaluation pilots. The selected glider type was Hans Jacob’s design, the DFS Meise. (Unfortunately WWII swept away the decision of IOC.)
During the years before and during the war Rotter was an active glider instructor and pilot of the Air Scouts. When Hungary went to war and during the eastern campaign in 1943 the Hungarian troops took hold of a couple of Russian gliders - one Gn-7, five G-9 and one S-10 – the Gn-7 were allocated to the Air Scouts. This high performance glider was test flown by Rotter.
The war in Europe was not yet over when Hungary’s first new government entrusted him with the task to find and collect all aviation related material in the country.
After the war he participated in reorganizing gliding however his actual flying career was practically over. He had never flown gliders again in Hungary after the war. In 1947 he was elected as president of the new Gliding Club of MADISZ (Hungarian Democratic Youth Association) and as one of the top managers of Danuvia Works (a Hungarian machine factory), where he worked from 1936, he helped the Works’ Aeroclub as well. Under his leadership the first aviation periodical after the war, the “Repülés” (Flying), was published by the Gliding Club of MADISZ in 1947.
His professional career more or less followed the pattern of the pre-war years, however after 1956 industrial leading posts were denied to him. Between 1949 and 1952 he was the technical director of the Hungarian Aircraft Repair Works, Székesfehérvár. After he left this post in 1952 he worked for different industrial works up to his retirement. There was a period when he even worked in the design bureau of the Central Experimental Plant, Alag (AKKÜ). He was a praised lecturer at the Technical University of Budapest on precision engineering. He remained in contact with gliding and was active in different organizations promoting gliding: Hungarian Aeronautical Association, Aircraft Section of the Scientific Society of Mechanical Engineering, Society of Transportation Sciences, Museum of Transportation, just to mention a few. After 1960 he had occasionally flew gliders abroad, however this activity of his was interrupted by a stroke which left him with a paralyzed left side. He died in 1983.
At August 19, 1993, a bronze bust of Lajos Rotter Sr. was unveiled at the top of Hármashatárhegy.