On 29 June 1940 the LaGG-3 was accepted for production and the first plant to build LaGG-3's was Plant No.23 in Leningrad and was tested in December 1940. As soon they were built, the first aircraft were sent to their units in Soviet Asia. The LaGG-3 proved immensely unpopular with pilots. It was somewhat hard to control as it reacted sluggishly to stick forces. In particular, it was difficult to pull out of a dive, and if the stick was pulled too hard it tended to fall into a spin. As a consequence, sharp turns were difficult to perform. Moreover, pilots reported several imperfections: badly made hydraulic systems, broken connecting rods, oil leaks, engine overheating, rapid engine wear and loss of power. Other faults included, defective landing gear, tail wheel failure, poor quality cockpit glass, poorly finished cowling panels, and poor quality delta wood panels due to rushed production, as a result of the German invasion. The quality of aircraft varied widely from factory to factory.