Boeing claims the 787 has reduced fuel usage by 18 billion pounds over the aircraft it replaced:
That's a lot of emissions. Unfortunately, I don't see airliners making it to "sustainable transport" any time in the foreseeable future.
Excess power can be used to make syngas from cracked water and CO2 in the atmosphere for processing into liquid fuel. The liquid fuel can then either be sequestered (say, pumped back into the oil wells) or used later either as a (fairly inefficient) way to store energy, or to run engines where batteries just don't cut it yet.
"Unfortunately, I don't see airliners making it to "sustainable transport" any time in the foreseeable future."
I hear Elon's got an idea about an E-jet, and we've seen what happened to his last several ideas so....
There is indeed a lot going on with elecyric and hybrid propulsion to geg ready for when the batteries are light enough. Probably 20.to 30 years for large airplanes...
It seems odd to weigh fuel?! Gallons, liters sure. But pounds?
Pounds are critical for an airplane in terms of balance, max takeoff weight, landing weight, etc. So fuel is almost always discussed in terms of pounds to make it easy for the Pilot to determine the take-off weight of the plane, engines are rated in terms of pounds of fuel/hour to make it easy to determine the landing weight of a plane, etc.
Yes, it's weird, but it makes sense in that usage.
Now, let's discuss the oddity of using Knots for airspeed...
Fuel is always measured in pounds because that reflects the real energy content- density of aircraft fuel varies depending on blend- it is denser for hot places (lower vapor pressure) and lighter for cold areas (so it doesnt freeze). Density varies between 6.5 and 6.8 lb/gallon.
Knots are NOT AT ALL odd. A nautical mile is defined as one minute of latitude- a degree of latitude is 60 nautical miles. Air AND nautical charts are all mercator projections, and use of nautical miles simplifies navigation since it lines up with latitude markings.
Finally wrt electric planes- see below for Reuters quote:
NEW YORK (Reuters) - A Seattle-area startup backed by the venture arms of Boeing Co ( BA.N ) and JetBlue Airways Corp ( JBLU.O ) plans to bring a small hybrid-electric airliner to market by 2022 that can dramatically reduce the travel time and cost of trips under 1,000 miles (1,600 km), it said on Thursday.
The first of several aircraft planned by Zunum Aero would seat up to 12 passengers and be powered by two electric motors.
Electric-vehicle batteries, such as those made by Tesla Inc ( TSLA.O ) and Panasonic Corp ( 6752.T ), would power the motor. A supplemental gas engine and electrical generator would be used to give the plane a range of 700 miles, Matt Knapp, co-founder and chief aeronautic engineer of the Kirkland, Washington-based company, said in an interview.
Zunum has no commitment to Tesla or Panasonic.
A larger plane seating up to 50 passengers would follow at the end of the next decade, and the range of both would increase to about 1,000 miles as battery technology improves, Knapp said.
The planes eventually would fly solely on battery power, and are being designed to fly with one pilot and to eventually be remotely piloted, he added.
Several companies, including Uber Technologies Inc [UBER.UL] and European planemaker Airbus ( AIR.PA ), are working on intra-urban electric-powered self-flying cars.
Zunum does not expect to be the first to certify an electric-powered aircraft with regulators. It is aiming to fill a market for regional travel for airlines, where private jets and commercial jetliners are too costly for many to use.
“Airlines are very keen to know how to fly a shorter distance and make money on it,” Knapp said.
Recent advances in electric-vehicle and autonomous technology, along with lightweight electric motors and carbon composite airframes would reduce the cost of flying Zunum’s aircraft to about 8 cents per seat-mile, about one-fifth that of a small jet or turboprop plane, Knapp said.
“We’re getting airline pricing down on a small plane and doing it for short distances,” Knapp said. “That kind of aircraft doesn’t currently exist.”
Zunum announced plans for electric-hybrid aircraft in April, and revealed that Boeing HorizonX and JetBlue Technology Ventures had invested in its initial round of venture funding. On Thursday it disclosed specifications and a timetable for the vehicle entering service.
Zunum says the plane would cruise at about 340 miles an hour and at altitudes of about 25,000 feet (7,600 meters) - slower and lower than jets.
The plane would cut travel time by allowing passengers to fly from thousands of regional airports, avoiding big hubs used by major airlines and airport security required for larger planes. About 96 percent of U.S. air traffic travels through 1 percent of its airports, Zunum said.
Current battery technology can only power the plane for about 100 miles so a gas-powered engine is used to generate electricity to power the motors for additional range.
Interesting story how metric vs imperial caused an emergency landing.
Yes. The root issue was that the fuel quantity indicating system waa inoperative so they used dipsticks. Canada had just switched to metric. The dipsticks were calibrated to liters but the mechanicw thought they were gallons!
What a spectacular landing!
Another problem was that, unknown to the pilots, the abandoned runway had been converted to a recreational center, including auto and go-cart racing. In one of the many weird coincidence of the day, July 23, 1983, was the “Family Day” for the Winnipeg Sports Car Club: “Go-cart races were being held on one portion of runway 32L and just past the dragstrip another portion of the runway served as the final straightaway for a road course. Around the edges of the straightaway were cars, campers, kids and families in abundance…”
Anyone know whether jet liners can weight themselves these days?
Thanks for the info guys. The more you know!...
Thanks, D'Tsea. I knew that at one time.
Although I still don't buy into Knots - how often are you navigating due North/South? Aviation inherited it from maritime navigation, back to the days of sailing ships and sextants and all the way back to astrolabes. They'll still be using it a hundred years from now, mostly to be obstinate, along with measuring altitude in feet.
Who's the obstinate one? The one who thinks folks who spend much of their time hundreds of miles away from everyone else any should change something that has worked fine for 500 years? Or the one who lives with it and doesn't want to?
I'm, personally, glad that Napoleon didn't decide to come up with his own angular and time measurement standard, deviating from a least-primes standard to a base-10 standard. This way, we at least we don't get parochial battles about among people who really don't understand the basic principles behind measurement.
Remember that every chart has the north south latitude scale repeated on it, meaning there is always a scale of nautical miles near your point of interest. It is trivial easy to simply run your dividers or parallel rules over to it to grab a nearby reference. It turns out the nautical miles is also easy to convert to either SI or Imperial units since 1 nm is about 2000 yards as well as being about 2 km. This makes real-world approximations in one's head very easy when one runs into someone living in a different standard domain.
In my live, I regularly deal with nautical miles, km, and feet. To me, rather than badmouthing folks and communities with different preferences, I find it easier to just make sure units are provided with each measurement since the units favored by Henry VIII, Napoleon, and Magellan aren't likely to merge any time soon.
Besides, there are benefits to each approach. Embrace the diversity.
Earl and Nagin +1
Earl and Nagin - well stated +10
@Earl and Nagin ... (October 6, 2017)
<< ... I find it easier to just make sure units are provided with each measurement since the units favored by Henry VIII, Napoleon, and Magellan aren't likely to merge any time soon. >>
Excellent point, @E&N ... !