An increase in the average 14,000 hours which new CFM56-3 engines spend on the wing before requiring a visit to the shop is in prospect, after a 95-hour testbed demonstration of recently-completed HP compressor and turbine aerodynamic modifications. CFM is now considering an upgrade modification kit that will give operators improved fuel efficiency, lower maintenance costs and longer on-wing life, together with a modest improvement in specific fuel consumption.

With almost 4,000 CFM56-3 engines in service propelling twice as many Boeing 737 Classics, a lot of airlines stand to benefit.

CFM said the tests showed a 15 degrees Centigrade increase in EGT margin could be achieved, together with longer turbine component life and lower repair and replacement costs.

By Bob Rodwell