The LAZ-699 Carpathian had 36 adjustable seats equipped with earphones, lights, ashtrays, glass holders, folding tables, and storage nets, a toilet and wardrobe in the rear, and a buffet, thermos compartment, and refrigerator in the front.
Its power unit was a YAMZ ZiL-375 and the 180-horsepower engine, installed in the rear, was sealed to make the interior soundproof.
A second fuel tank increased the bus's range, and its maximum speed was 97 kilometres per hour (60 mph).
The prototype was brought to Moscow in 1961, where it was shown to the public (including Soviet Premier Nikita Khrushchev).
Unlike the earlier prototypes, the new buses now had round rear-wheel arches and split direction indicators similar to the urban LAZ-695.
Its lack of power steering made it difficult for drivers to control the bus, especially on dirt roads.
Other problems included an unreliable frame, windows with a tendency to fall out, a leaky roof and engine compartment, and unacceptably high fuel consumption.
[14][15] In the fifth and final Carpathian prototype, the four headlights were reduced to two and the front-wheel arches were rounded to match the rear wheels.
The body extension which had resulted in poor frame rigidity during prototype development was never fixed, and production of this model was discontinued in 1964 after few buses were produced.
During the 1960s, the bus's design evolved from round, borderless forms and sloping roofs to clearly bordered and edged body parts.
The Raba axles had a planetary transmission in the wheel hubs and a larger brake-pad area, which reduced braking distance.
Removal of the sloped roof led to better body rigidity and allowed the installation of larger windows, which improved passive cooling of the passenger cabin.
The number of seats remained the same (41), and the luggage compartment expanded to 4.38 cubic metres (155 cu ft).
The LiAZ-677, with its capacity of 110 passengers, negated the need for a bus like the LAZ-699B; only one was built, by the All-Union Experimental Construction Institute in Lviv.
The interior was equipped with two televisions, radio systems, a buffet, a toilet, a refrigerator, a coffee machine, and a gas stove.
The bus had a modified 375-horsepower ZiL-375Ya5 engine, a hydraulic clutch booster, a two-section brake system, and a pneumatic telescopic suspension.
Other new features included a climate-control system and an automatic, electric two-section entry door which opened outwards.
[26] A 1974 prototype was equipped with the 210-horsepower diesel YAMZ-740, the engine intended for the Ukraine-73, and was shown to the public at the 50 Years of Avtoprom exhibition in Moscow.
Three large, comfortable, rotatable astronaut seats were installed on the left side, matching the future Soyuz-T spacecraft for its three-person crew.
Passenger compartment two included nine comfortable seats, a toilet, buffet, refrigerator and wardrobe for accompanying personnel, who were banned for epidemiological reasons from contact with the astronauts.
The rear door was in the middle section and led into a lock chamber, where a vacuum cleaner sucked dust off the spacesuits.
In stationary operation, the bus was heated and cooled by an electrical system consisting of 12 LN-1 heater fans.
The second section, between the two main compartments, included one seat, a wardrobe and a vacuum-cleaner cupboard; the vacuum cleaner removed dust from space suits.
In more than 20 years of production, the model underwent a number of modifications but the main parts and body design remained the same.
The buses had rectangular headlights until 1981; early models had a false radiator screen, which was removed at the end of the 1980s.
Typical of this model were decorative black plastic parts such as hubcaps, a false radiator screen and air intake, and a front bumper with fog lights.
The bus had some advantages, however; due to its simple construction, it was reliable on the hard dirt roads typical of the Soviet Union.
[29] After the dissolution of the Soviet Union and the associated increase in fuel prices, the petrol-powered ZIL-375 engine originally intended for the military all-wheel-drive Ural-375 truck became obsolete.