Tuesday, May 7, 2013

Design of engine for Boeing 737 Max completed

The topic is the Max 737 Engine design freeze from CFM.  The Puget Sound Business Journal brings this discussion to light. The Journal follows with the announcement, about the CFM 737 Max engine:

"CFM International engineers have locked in the design of the Boeing 737 Max engine, moving the aircraft upgrade a significant step toward reality. The completion of the engine design paves the way for configuration of the rest of the airplane."


"The May 2 design "freeze" of the LEAP-1B engine means engine manufacturer CFM International can now start developing and releasing the digital files, still referred to as “drawings,” that will guide milling machines in cutting engine parts.
CFM International is a joint venture between General Electric and Snecma, a French company.
The first 737 Max engine is to be assembled in early 2014, then tested and then certified over the next two years. Boeing’s 737 Max, a re-engined version of its current 737 “Next Generation” model, is to enter service in 2017. Boeing now has 1,235 orders for the 737 Max, making up 39 percent of the total 737 backlog."
May 2, 2013 is a benchmark date for the program because the engine sets the tone for everything tied to the power unit: from back-up systems, wing design, and operational capabilities. A serious Max fine tuning can now begin in engineering. After which testing, and then the full sized test aircraft.
All other design changes start in earnest, once the engine is confirmed at CFM. They will need to validate its power, fuel consumption and reliability. Proving within the fixed design parameters.  Those set parameters are now firm, triggering the start of everything it takes to build the Max. Testing will cause subtle changes within those limits, maximizing that the engine performs, according to the computer screen theory. Making a long process before it is set under the wing.

The immediate affected areas on the Max from Engine design freeze are:


  • Position of engine on the wing, distance forward or back to the center of the aircraft gravity from setting the Max Engine power, weight and engine diameter. The items affect the power vs drag issues. Now Boeing must have decided on engine diameter and the mounted wing position.


  • Nose gear length will now freeze affected by engine size specifications and and its gear housing requirements.


  • Any electrical design changes can now occur post engine design freeze.


  • All backup safety systems will conform to the CFM design freeze.


“In general, we’re trying to change as little as possible about the airplane,” Penning said, adding that the engine design freeze is “huge for our program.”

Boeing and CFM engineers have been traveling between the two companies during the development phase.
“We work hand in glove with all of the air frame customers, they know everything we’re doing,” Jewell said. “We share the results with Boeing, it informs what we do with the airplane.”
This answers a lot questions about the above bullet points, Boeing is freezing many of the loose ends along the way when CFM was comprising the CFM towards design freeze.  We know that an inch forward or an inch back for the engine on the wing affects airplane lift and drag performance. It was previously stated the landing gear is depending on the final engine configuration. As stated in this article, they have reduced a thousand pounds in the engine area. The 787 project was remise, when it gained a 180 pounds weight, implementing its stainless steel fire box on its battery system. Weight and the numbers of passenger seats are the main ingredients in the Max-Neo wars. This is an apple to apple war, not a metal to plastic war, found in the WB's.
Those two items directly affect performance.  Shaving off a thousand pounds off the engine area is a big thing in that war. The Max has shaved many other pounds off, over its predecessor, the NG.  The game afoot is the weight reducing without losing functionality. If in fact you increase its raw performance for an engine and reduce its weight you have won the daily double.  A better and lighter engine that is sitting on a test block, and then mounted onto a lighter more streamlined body, and then hooking it up with optimizing management system, bears the name, Max. The Design freeze on the engine represent those things just mentioned.
CFM's Max Engine Frozen on the Block, awaits a wing to fly.
That is how Boeing is stacking its performance numbers against the competition. Percent improvement (%) from the engine, another from body and wing design (%), and more from weight reduction (%), is how they claim a 17% fuel savings on the Max over its former models. Plus I haven't forgotten (%) improvement from Max systems management. The NG is just ahead of the A320 in the first place. Now the Max will challenge the Neo.  
The last trump card Boeing will play with all its new advanced technology will play out in 2030's on an all plastic super single aisle construct.