Jurgis Dobkevičius built his first plane - the DOBI I - privately and with his own funds, so there are no documents regarding this plane in the military archives, however, according to foreign journals (Dobkevičius himself supplied them with information and even sent plans) the plane was built in 1921. The first test flight happened next year, when the plane wasn't fully finished yet (the engine wasn't fixed properly, but thankfully everything went well) and more testing happened in autumn, when it was found that the plane was manoeuvrable, quite hard to land (this is probably why Dobkevičius never let anyone else fly it), had minimal view forwards and, surprisingly enough, with its 35HP engine, incredibly fast (175km/h). In 1923 the engineer set out for a flight to St. Petersburg, but due to multiple malfunctions he had to return back to Kaunas. Finally, in 1925, while landing the DOBI I clipped a horse carriage and crashed, Dobkevičius broke his leg.
Unlike DOBI I, DOBI II was now built officially for military aviation in 1922 for the Lithuanian Air Force, which was searching for fighter and recon planes. J. Dobkevičius started with a recon design, which was supposed to be fast and have a high service ceiling. In 1923, after test flights, DOBI II turned out to be the fastest two-seater plane with an engine of 200HP, and Dobkevičius already planned a 1000km flight from Kaunas to Prague. However, Germany wouldn't allow flights to pass their air space without landing for a check-up, so when the DOBI II set out for Prague and had to land in Koenigsburg, due to poor visibility and (who would of guessed) difficult landing abilities, the plane crashed. However, it was then repaired and sent back to Lithuania, where J. Dobkevičius was now focusing on his new project. Jonas Mikėnas was the first pilot Dobkevičius allowed to fly his planes, however although he was regarded as one of the most experienced pilots in Lithuania, he still didn't manage to land the DOBI II properly and, you guessed it, crashed while landing. It was never repaired.
DOBI III was the first and only purpose-built fighter plane of the Lithuanian Air Force. It was built in 1924, with such relatively new and unheard of features as retractable landing gear (it was planned, and Dobkevičius still built the plane so that it could be done, but found no workshop able to build such a mechanism) and surface radiators, used a powerful new BMW engine and specially engineered wings to provide maximum lift and speed, so that the plane could dive while attacking and gain altitude again quickly. Little is known about its flying properties, as J. Dobkevičius hurried the production (according to J. Mikėnas, this was his notable trait) and only managed two test flights, which both ended in a crash. During the last flight, in 1926, J. Dobkevičius attempted to land three times, however he clipped telegraph wires, then a tree and finally crashed. Jurgis Dobkevičius died several hours later in hospital.