Around 500 kg less Co2, every curved landing within the "Vinga project" in Gothenburg so far. And idling is not prohibited!
Canīt we just keep off the grumpyness, cynisism and quarrelling here, and be constructive?
Your subsequent citation says the "MINT" project is the one that has reported results, not the "Vinga" project (which starts next year). Since there is no illustration of the criteria used in the curved and traditional approaches into Stockholm, there is no way for us to tell how that curved approach supposedly saves fuel. If a different vertical profile is used in addition to a curved lateral approach path, why is the different vertical profile not used in the traditional approach?
"Idling" (use of idle thrust) is indeed prohibited on final approaches under the "stabilized approach" criteria in place in every airline I know of. Current use of FMS with VNAV capability already calculates a profile based on idle thrust until intercepting final approach, so there is NO difference between a traditional VNAV arrival and approach and any optimized "curved" approach in this respect. Any gains in fuel efficiency are likely due to ATC involvement, where test airplanes are allowed to fly their preferred arrival and approach profile without ATC intervention. If airplanes were allowed the same clearance on a traditional arrival and approach, there would be little or nothing to be gained by a curved lateral final approach profile.
Also, you have not addressed the offset in fuel burn for the case where an "efficient" airplane is given priority and another airplane has to delay because of it. How is Novair "green" by suggesting that other airplanes burn excess fuel instead of themselves?
There's no grumpiness or cynicism here. There are many valid questions about test methodology, side effects, and validity of test reports. There are also valid questions regarding what EXACTLY is the definition of "green" in your context, and whether that definition is actually valid is a gross ecological context. Too many companies and researchers are promoting "green" products and techniques that are nothing more than eyewash. A "priority" scheme that forces other airplanes to burn more fuel is NOT "green"; and neither is an approach profile that makes use of priority handling not available to aircraft at large.
UPDATE -- I just looked at a MINT demo at
Mint Demonstration Flight Part 1 .
There is NOTHING in the demo that requires or relies on a "curved approach." That they happen to use a "curved" lateral profile for the intercept of the final approach course is only incidental, and likely due to noise considerations for the specific airport in the demo. Any fuel savings appears to be SOLELY due to the shorter arrival/approach profile and priority handling by ATC, allowing shorter flight time and use of the preplanned VNAV and LNAV profiles.
If you have other info that contradicts this analysis, please post it.