As the search to improve the impact of aviation on the Earth's environment goes on, Pratt & Whitney is talking up the advantages of its PW6000 engine, the only engine designed specifically for 100-passenger aircraft.

The PW6000's balanced approach to low emissions produces the lowest overall emissions while satisfying the Zurich Class 5 rule for low NOx and HC. The engine easily satisfies, at all conditions, Stage 3-4 dB and will satisfy Stage 3-5 dB with trades.

This performance enables PW6000-powered aircraft to fly more frequently into airports that have noise quotas or curfews. It will minimise airport charges and environmental restrictions and will protect operators against added cost from future regulations.

Reduced turbine operating temperatures and advanced cooling schemes make the PW6000 one of the world's most durable and reliable engines. In fact, reliability at entry into service will equal or exceed that of mature engines currently on the market.

For typical 100-passenger missions, the first shop visit should not occur before almost six years of service. And the interval between scheduled shop visits will be nearly as long as the engine's first run time on wing.

This reliability results from six Extended-range Twin-engine Operations Style (ETOPS) tests prior to EIS. The engine will endure unprecedented testing on two flying test beds. A hiatus in the testing schedule allows design teams to assimilate test data and redesign parts that did not meet P&W's standards.

Low cost is also built into the PW6000's design. The single-stage turbine keeps the engine's parts count to a minimum, and the engine's solid-fan airfoils (the PW6000 has half the number of airfoils found in comparable engines) are less expensive to manufacture than conventional airfoils. The cost of the PW6000 airfoils is about one-third that of competitors'.

Other parts are either made from more economical material or assembled using streamlined manufacturing processes - both ultimately permit lower product costs to the operator.

Once the PW6000 engines are airborne, their life limited parts (LLP) uniformity enables operators to plan and budget accurately for maintenance. And P&W's Fleet Management Programmes guarantee that no shop visit will occur simply to change out expired LLPs.

When the engine does need to visit the shop, advances in product design and materials keep maintenance costs low. The PW6000's Floatwall combustor, made of common nickel steel with thermal barrier coating, allows operators to replace individual panels rather than make the costly weld repairs that a rolled ring burner requires. This provides a significant cost benefit, since maintenance is a prime component of engine-related operating costs on short-cycle missions typically flown by smaller aircraft.

The five-stage high compressor and single-stage high turbine also help keep maintenance costs to a minimum. And the accessory gearbox and other mechanical components have been simplified to cut maintenance time and minimise the probability of maintenance errors.

Source: Flight Daily News