The Aviadvigatel/Perm Motors PS-90A turbofan programme has been severely crippled because of a lack of funding, which has severely compromised the manufacturer's ability to overcome technical problems which have left the engine with a reputation for poor reliability.

Series production of the engine was conditionally approved by the CIS Aviation Registe, early in 1996, for an initial two year period, with the stipulation that reliability problems must be ironed out during this time.

Aviadvigatel was dealt a severe blow in July when Aeroflot - Russian International Airlines signed an agreement with Ilyushin for a feasibility study into re-engining the airline's PS-90A-powered Il-96-300s with more reliable Pratt & Whitney PW2037s.

The Russian company claims that service-life between overhauls has now been increased to 3,000h, helped by the introduction in January of a revised combustion chamber and the elimination of an inter-shaft bearing. It is understood that the PS-90A production rate has now increased, after only a handful were manufactured in 1995.

Meanwhile, Aviadvigatel is testing a modified version of the D-30KU, which is used to power Tupolev Tu-154 and Ilyushin Il-62 airliners, incorporating the PS-90A's gas generator.

The manufacturer predicts that the derivative will deliver a 7% reduction in fuel burn, compared with earlier models.