Andrzej Jeziorski/WARSAW

THE WARSAW-BASED Aviation Institute (IL) has shelved development of its D-18A twin-shaft turbofan engine because of lack of funds and doubts over its applications.

The 18kN (4,000lb)-thrust engine, which had its first bench test on 16 April 1992, was intended to power future dedicated combat versions of the PZL-Mielec I-22 Iryda jet trainer. With the Iryda programme under fire from its sole customer to date, the Polish air force (Flight International, 28 February-5 March), the Institute now doubts whether these developments will ever materialise.

"The development of the Iryda looks as if it will stop on the level that we are working on," says the Institute's scientific director, Wojciech Potanski.

The Polish air force owns four M-93 versions of the Iryda, powered by 15kN K-15s developed by the IL and produced by PZL-Rzeszow. Three more M-93s await delivery at PZL-Mielec.

Four earlier I-22 variants, powered by the 11kN PZL-5 turbojet, are also in service. These aircraft have been criticised for being under-powered, and are to be retrofitted with K-15s this year.

Training flights using Irydas have been suspended following the crash of an air force I-22 in January. The Aviation Institute is now working with PZL-Mielec on improving the aircraft's aerodynamics.

PZl-Rzeszow has begun work on a more-powerful variant of the K-15 engine, known as the K-16. According to company president Tadeusz Cebulak, it will have a thrust rating of some 16kN although, compared to its predecessor, its technical differences will be minor.

Cebulak plans to have two test engines running by the end of this year, in the hope of interesting the Polish air force. He says that, although the air force has as yet expressed no formal requirement for an even more powerful engine, he is confident that the resulting improvements in payload, climb rate and take-off performance will prove irresistible.

Source: Flight International