Boeing has launched a new interior and upgraded CFM International CFM56 engine for the 737NG family of narrowbody aircraft.

The manufacturer plans to introduce the CFM56-7B Evolution powerplant in conjunction with a new interior to deliver a 1% improvement in overall aircraft efficiency. Boeing will also make minor tweaks to the aerodynamics of the aircraft to contribute to a 1% improvement as well.

Launch customers include FlyDubai, Continental Airlines, Malaysia Airlines, TUI Group, Norwegian, Gol and Lion Air.

CFM will deliver the improvement by reshaping the blades and vanes of the high- and low-pressure turbines to increase airflow through the engine and reducing overall temperature, says director of CFM56 Boeing programs Robyn Brands.

Boeing and CFM will introduce changes to the engine nozzle and plug, and remove approximately 9% of engine airfoils from the high- and low-pressure turbines, to reduce maintenance costs by up to 4%.

Aerodynamic changes to the aircraft include a reshaped anti-collision light, refined wing control surfaces, revised main landing-gear wheel-well fairing and a modulation of the environmental control system inlet and exhaust.

Boeing and CFM are aiming these changes at carriers operating 737s in stages greater than 1,000nm (1,850km).

“The longer you’re in cruise, the more fuel burn improvement you’re going to get,” says 737 chief project engineer John Hamilton.

Video: FlightBlogger interview with John Hamilton

CFM says it will be able to offer the engine improvements to existing CFM56-7B operators through spares and overhauls in the future. The engine maker says it will continue to support the -7B technology insertion package introduced in 2007, as well as the base -7B configuration engine.

The technology changes represent a $100 million investment for CFM. Overall, Boeing hopes to deliver around 2% improved fuel consumption for 737NG customers.

Video: Interior lighting demonstrated

CFM’s first Evolution engine will be ready September 2009 and the company says it is already testing Boeing’s engine nozzle improvements at its Peebles, Ohio facility.

Tests will include 150 hours of block testing beginning in January 2010 that will see the engine run at maximum core speed, maximum fan speed and maximum operating temperature simultaneously – also known as triple redline – for 30-hour intervals.

Following each continuous 30-hour triple redline run, the engine will be spooled down, not shut down, then operated again under the same conditions for a total of five 30-hour triple redline runs.

Brand adds that if an engine were to achieve triple redline in service for even 20 seconds, the US FAA would require the operator to remove and overhaul the engine, emphasizing the brutal testing to which the new Evolution engine will be subjected.

CFM will flight test the Evolution on General Electric's venerable Boeing 747-100 in February of 2010, ahead of a joint US FAA and European Aviation Safety Agency certification in July 2010. Once certified, the Evolution engine will be branded as the CFM56-7BE.

Boeing will utilise a Continental 737-800 to flight test the changes in October 2010 ahead of certification in the second quarter of 2011, followed by entry into service in mid-2011 – when the aerodynamic enhancements are also scheduled for introduction. The interior will enter service in the fourth quarter of 2010.

FlyDubai will be the launch customer for the 737 ‘Sky Interior’ which features new colour-LED lighting, larger 777/787-style pivot bins, new sculpted sidewalls, revised window design, a flight attendant touch-screen panel, and changes to the individual passenger reading-light panel.

Boeing also hopes to deliver a 2-4dB reduction in cabin noise. The interior improvements mark the most significant change to the type’s cabin since its introduction with Southwest Airlines in 1998.

The weight-neutral interior will be a priced option for existing 737 customers and be a mandatory priced ‘option’ for new customers. Boeing declines to discuss the adjustment in price of the new features.

While technically possible to retrofit current 737NGs, Boeing says this is “not feasible” because the cost would be prohibitively high.