A milestone of great note passed last week with hardly a notice. The Sonic Cruiser, which would have accelerated air travel from Mach .84 to Mach .98, turned ten years old, according to the March 22, 2001 date on its patent filing. Its life as an conceptual product was brief, but notable, eventually transforming its design elements into what we know today as Boeing's 787.
The market demise of the composite canard delta wing design, was in part driven by the fifty-year erosion of the need for 'higher, faster, farther' aircraft to those that delivered 'faster, better cheaper' results, as reflected in Piepenbrock's Toward a Theory of the Evolution of Business Ecosystems. The Sonic Cruiser's market reception - or lack thereof - was ultimately the result of the market reality to compete on cost (efficiency) rather than speed (performance).
In short, going slow is much cheaper than going fast. In a business where time is money, going fast on the ground and slow in the air pays tangible dividends.
This week's Flight International features a flight test aboard the new stretched Bombardier CRJ1000, the 100-seat latest evolution of the original Canadair Business Jet design, that builds on CRJ's 700 and 900. As our pilot Mike Gerzanics set out to demonstrate the fuel burn of the new jet's General Electric CF34-8C5A1 engines, he found the CRJ1000 could keep up with faster traffic, but at a price:
Once level, I established M0.78 cruise point, Bombardier's recommended normal cruise speed. I found the airspeed tape's trend arrow allowed me to expeditiously set and hold the desired speed. A total fuel flow of 1,480kg/h was needed to hold M0.78/262kt with a resultant true airspeed of 454kt.
Next, the power was increased and an M0.80 cruise speed was established. Total fuel flow increased to 1,740kg/h with a resultant true airspeed of 473kt.
My back of the napkin calculations revealed an interesting set of figures. For a 2.6% increase in Mach number, fuel flow had to increase 17.6% at cruise. Translating these figures into dollars and cents, a flight from Chicago O'Hare, where Jet A is $7.47/gal today (according to AirNav), pulling back that throttle to M.78 saves $638 an hour in direct operating cost. ($4,275 vs. $3,637/hr)
My intent is not to single out the CRJ1000 as an example of neither high nor low fuel burn, but rather to provide real-world data point about the big impact small changes in speed can bring.
While the CRJ1000's trans-sonic wing is optimized for a M.78 cruise, it offers a good example for how slowing down can improve fuel efficiency and direct operating cost.
The Sonic Cruiser is the extreme example of when the market doesn't
want a product that flies higher, faster or farther, it just wants a product that arrives off the production lines faster of better quality
and cheaper to operate.
Yet if all the airframers, engine makers and airlines are looking to spend billions to deliver a 15% improvement in fuel burn that satisfies the need for faster, better, cheaper with a new aircraft and engine combination, are we perhaps looking in the wrong place?
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While the CRJ1000's trans-sonic wing is optimized for a M.78 cruise, it offers a good example for how slowing down can improve fuel efficiency and direct operating cost.
The Sonic Cruiser is the extreme example of when the market doesn't
want a product that flies higher, faster or farther, it just wants a product that arrives off the production lines faster of better quality
and cheaper to operate.
Yet if all the airframers, engine makers and airlines are looking to spend billions to deliver a 15% improvement in fuel burn that satisfies the need for faster, better, cheaper with a new aircraft and engine combination, are we perhaps looking in the wrong place?
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