Yak-58: A SMALL PIGEON TO CARRY GREAT MESSAGES

Yuri Yankevich

Research Supervisor

Avtandil Khoperiya

Director General of the Tbilisi Aviation State Association

or the first time, aviation specialists, journalists and potential buyers were familiarized in January 1991 with a new development of the Yakovlev Design Bureau – the Yak-58 light multipurpose six-seat airplane, whose full-scale mock-up was demonstrated at the assembly shop of the experimental plant.

Yak-58 six-seat airplane

A comprehensive analysis of the air transportation service market had been made before designing the Yak-58 to determine the needs for a comparatively small airplane that would be cheap to produce and service and could operate from unpaved airfields. Over 80 surveyed organizations, institutions and enterprises came out in favor of such an airplane. So, the former Communications Ministry of Kazakhstan alone was ready to purchase several dozens of the Yak-58 to replace the An-2 airplane for flying over more than 700 pastoral ranges for sheep-breeding.

For reducing financial expenditures and the duration of the airplane's development, the Design Bureau administration came up with a nonconventional solution for building the prototype airplanes at a serial aircraft manufacturing plant. In June 1992, General Designer Alexander Dondukov and Director of the Tbilisi Aviation State Association (Russian acronym TAGO) Avtandil Khoperiya signed a purpose-oriented program to develop and construct the Yak-58. In September of the same year the agreement was signed between Russia and Georgia on the development and manufacture of the airplane, one of the first agreements of its kind between the former Soviet Republics.

Already in August 1993, the prototype of the Yak-58 was exhibited at the Moscow Airshow and in December test pilot Alexander Vyatkin made the maiden flight from the TAGO airfield.

The Yak-58 is a general-purpose aircraft and is intended for business and executive flights, carrying of passengers or small cargoes and flying special missions, such as transportation of a sick person with one accompanying person, geological survey, aerial photography of terrain, ecological investigations of biosphere, patrolling of forests, gas and oil pipelines, power transmission and communication lines, as well as training of pilots.

The airplane is designed in compliance with the AP-23 and FAR-23 airworthiness standards and fully meets the present-day requirements for flight safety.

The airplane is powered by the M-14PT1 domestic piston engine rated at 400 hp with a three-blade pusher propeller developed under a license from the MT-PROPELLER Company (Germany). A reduction gear with the low-speed propeller ensures a low level of noise generated by the airplane on the terrain.

The airplane is furnished with an all-metal airframe featuring a two-beam low-wing configuration with a retractable tricycle landing gear.

The short takeoff run and landing roll required (610 m and 600 m, respectively), soft shock-absorption of the landing gear, low-pressure wheel tires make it possible to operate the airplane from limited airfields having no artificial pavement, as well as from minimally prepared unpaved sites and highways.

The airplane is furnished with radio communications facilities and flight-and-navigation equipment that allow it to carry out flights by day and at night and ensures the ICAO Category I approach.

The convenient cabin layout, arrangement of the power plant in the tail section, high field of view from the cabin, modern design of the seats featuring adjustable seat backs, availability of cabin ventilation and heating systems ensure the comfortable conditions for the pilot and passengers.

With a maximum takeoff weight of 2,100 kg, the airplane can carry 600 kg of commercial payload to a range of up to 1,800 km at an altitude of up to 4,000 m and cruising speed of 230 km/h.

By the present time, three Yak-58 airplanes have accumulated more than 50 flying hours. The basic flight characteristics are confirmed and revealed drawbacks are being eliminated. This is the normal practice the purpose of which is to prepare the airplane for certification tests, which are scheduled to be completed next spring.

Twenty airplanes intended for sale to the Central Asia and Transcaucasian regions are at various stages of assembly at TAGO.

The assembly work of an airplane with two control stations is also in progress. This airplane can be used for training pilots and dual control.

To extend the capabilities of the airplane, together with France's Thomson-CSF Communications company, TAGO equipped one of the airplanes with a radio control system which allows for:
– patrolling of fishing areas and borders;
– interception of signals and direction-finding to a radio transmitter by means of a radio direction finder which processes the signals intercepted by listening antennas and automatically measures the direction and geographical position of the radio transmitter;
– listening to voice signals and recording them on the tape;
– visual inspection of terrain by day and at night using special optical equipment.

The airplane was demonstrated at Le Bourget '97 and MAKS '97 airshows. A number of interesting proposals were received.

For rendering the maximum promotion for the Yak-58 project, the Yak-Alakon-Aerokosmos Aerospace Financial-Industrial Group (AFIG) was established by Russia, Kazakhstan, and Georgia in August 1996.

One of the very first objectives of the established association is to manufacture the Yak-58 airplane as soon as possible. In 1997, the AFIG signed a contract with TAGO for delivery of 12 airplanes and received orders for another 100 airplanes.

Following the example of foreign countries, TAGO included in its immediate plans the establishment of the service infrastructure ensuring the sale and maintenance of the airplane, as well as training of flight and service personnel.