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  • New detail on flying wing airliner
    Posted by Guy Norris 3:52 AM on Jan 20, 2012

    Northrop Grumman has revealed intriguing details about the flying wing airliner and freighter versions it has proposed as the ‘preferred systems concept’ for NASA’s Environmentally Responsible Aviation (ERA) program.  


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    (all artwork Northrop Grumman)

    In a nutshell, ERA’s Advanced Vehicle Study goal is to identify an aircraft configuration which could make future transport aircraft cleaner, quieter and more efficient. With targets that are sporty to say the least, the ERA design teams led by Boeing, Northrop Grumman and Lockheed Martin, had their work cut out.

    For Boeing the study was pretty much business as usual, while for the NG and LM teams the exercise represented a rare excursion into the rarified, environmentally-challenged atmosphere of the commercial world.

    Northrop’s design marked high in points against ERA’s goals which for the N+2 aircraft, or an airliner that is roughly two-generations beyond today’s machines. The flying wing did particularly well in noise reduction, scoring around -74.7 db below the Stage 4 against an ERA target of 42 db. This is not surprising in some sense, given the shielding effect of both the buried inlets and recessed exhaust nozzles. For emissions, the team estimated the design could reduce these up to 88% below current levels (versus a 75% below CAEP 6 target). The area where more work remains to be done is in aircraft fuel burn which analysis shows is some 41.5% below 1998 levels against the target of 50%.

     
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    Passengers load up a ramp into the aft of the flying wing – which if you look carefully in this rendition is actually the cargo version. The passenger version center section is significantly wider than the cargo variant to maximize cabin volume and, including engine compartments, measures more than 79 ft across compared to 60 ft for the freighter. The span of the cargo aircraft is larger, however, by around 30 ft.


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    A military airlifter variant – which presumably could be adapted B-2A style for improved stealth – has a payload of 100,000lb and capacity for 12 full-size and two half-size cargo containers. Span is 260 ft and leading edge sweep is 40 degrees. The center section (including the broad engine installation) is almost 60 ft wide on the cargo aircraft

     


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    Of course it is not the first time Northrop has looked at flying wing airliners. In the 1940s the company’s publicity department came out with images (and even a movie) of what it hoped could be a vision of the future. The heritage of the YB-49 bomber, which never entered production, is as clear to see here as the B-2 heritage of the present day ERA concept.

     


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    A close-up view of the 1940s cabin – a little more elbow room (and smoking lounges and bars of course!), than the 2025 version with a tri-class layout for 224 passengers. Note (below) how the concept places first class right aft as loading and unloading would be via the rear of the aircraft.

     


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    The two PSC’s compared to the B-2A for scale

     


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    To demonstrate the concept, Northrop’s scaled testbed vehicle (STV) would be a two-seater powered by four GE Tech X future regional/business jet turbofans. Flight controls would consist of inboard and midboard elevons as well as split rudders.


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    Northrop predicts swept wing laminar flow could contribute more than 8% fuel savings and would be demonstrated partially by the STV.

     


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    STV measures 143 ft in span, and is around 65.5 ft in length. Max take-off weight would be an impressive 112,318 lb.

     
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    Internal structure of the STV, again presumably closely related to the B-2A, illustrates the spar cap loads from the three main wing spars are carried-through the fuselage and spread into multiple paths around the engines and payload. Unlike the B-2A, however, which has a central weapons bay with moveable doors, the STV would have a reinforced cargo floor for handling and bearing loads.

    Tags: awt, Northrop, Grumman, NASA, ERA, YB-49A, B-2A

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