Density altitude is the biggest factor in aircraft take off on a given runway length, temperature, and altitude. I know this from firsthand experience as I used to be a private pilot – until my hearing got so bad that I decided I was a danger to myself and others. This study published in the Bulletin of the American Meteorological Society claims the number of days with a density altitude issue at some airports will increase per RCP model scenarios in 2050-2070. Of course they are assuming that the RCP models produce an accurate output, and that airplanes of the 2050-2070 era have the same airfoil efficiency and takeoff power of today.
Climate change and the impact of extreme temperatures on aviation
Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, USA.
Abstract
Temperature and airport elevation significantly influence the maximum allowable takeoff weight of an aircraft by changing the surface air density and thus the lift produced at a given speed (Anderson 1999). For a given runway length, airport elevation, and aircraft type there is a temperature threshold above which the airplane cannot take off at its maximum weight and thus must be weight restricted. The number of summer days necessitating weight restriction has increased since 1980 along with the observed increase in surface temperature. Climate change is projected to increase mean temperatures at all airports and significantly increase the frequency and severity of extreme heat events at some (Scherer and Diffenbaugh 2013; Donat et al. 2013; IPCC 2012). These changes will negatively affect aircraft performance, leading to increased weight restrictions especially at airports with short runways and little room to expand. For a Boeing 737-800 aircraft, we find that the number of weight restriction days between May and September will increase by 50-200% at four major airports in the United States by 2050-2070 under the RCP8.5 emissions scenario (Moss et al. 2010). These performance reductions may have a negative economic effect on the airline industry. Increased weight restrictions have previously been identified as potential impacts of climate change (National Research Council 2008; US Global Change Research Program 2009), but this study is the first to quantify the effect of higher temperatures on commercial aviation. Planning for changes in extreme heat events will help the aviation industry to reduce its vulnerability to this aspect of climate change.
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Why did I allow my membership in the AMS to expire? The political silliness had taken total control of my professional society. Publishing this fantasy in the Bulletin is a good example.
John C, I shake my head and ask myself why I spend $100 a year for the aggravation of continuing to support this AMS drivel.
As a professional pilot and experienced meteorologist, I can only sigh and shake my head again at this particular study. Denver, Colorado Springs, Albuquerque, El Paso and SLC (to name a few) already have frequent weight-restricted flights. Weight restrictions apply most frequently to the regional jets and turboprop carriers. 1998 in West Texas and the High Plains was particularly painful to aircrews and passengers as luggage was removed without the knowledge of their owner to meet takeoff weight restrictions on hot, calm days and short runways. In my experience (anecdotally, I don’t have the stats) this has been much less of an issue since then. I don’t think it’s a coincidence that my experience corresponds to the “pause” or cooling since 1998,
From an aeronautical propulsion perspective, the study fails to recognize advances in engine efficiencies that by 2050 will offset much of their warming-based concerns. in 2050, 35 years from now, most of today’s 737-800s will be retired. Mark’s point (below) about Boeing’s engineers is spot on.
I am looking forward to joining the Open Atmospheric Society: http://theoas.org/about/
hifast- Agreed- back in the 90’s I was working as a Co- Pilot on a DC-7 airtanker out of ABQ,SLC etc, We ‘d depart ABQ south or west bound usually, and due to the high, hot, conditions and the fact that the R-3350 radials were ah, sensitive to temp extremes i,e, too hot, too cold, killed them, you did a METO climb very rarely past 500 agl and did a cruise climb at whatever would keep the temps down.
We’d have conversations with departure like this: “Ah do you know your mode C shows you BELOW field elevation?”-as we would dip into the Rio Grande Canyon to cool off and raise the takeoff flaps….
The Salt river drainage was handy at Phoenix too …
Now the next gen is coming on for Airtankers, RJ85’s BE146’s,MD87’s DC10’s
etc. Single engine airtankers or SEATS also..
Models are just that-nothing based on reality. the real world blows on past the model…What I am amazed at is density altitude issues on aircraft performance is treated like something new…
I guess the weight restrictions from warm temperatures means we will never be able to fly to the Sahelian countries, of the Gobi desert in summer. Shame. I was looking forward to the introduction of powered flight to Africa.
I will have to communicate this emerging danger to the Ukrainian pilots in the DRC who routinely take off with 150% overload from the Lubumbashi airport delivering equipment to the mining companies in the triangle.
I agree. It is said that with enough power you could get a brick to fly. But…you still face the expansion of air with higher temperatures which results in thinner air (like at higher altitudes) and less lift. Like in Denver, already at a high altitude, on hot summer days. Lucky that global warming has gone away except in the computer programs used by the IPCC.
Good post, hifast. I’m wondering just why this study was undertaken. I could find nothing in the abstract that wasn’t well understood long before I began flying just over 60 years ago. This forces me to conclude that they’re really getting desperate. Scare stories about the honeybee, the walrus, polar bears, coral, chocolate, glaciers. . . ad nauseam. In this case, they are simply projecting current aeronautical technology into a future that they assure us will be much warmer than today. No allowance for advances in engineering, adaptation (or even global cooling). Seems to me that this study, like many others, was another waste of taxpayer money.
You might be able to find a 737-800 in 2050 but you’ll probably have to find it in a museum somewhere.
JayB the 737 may be in a Museum in 2050, but Dollars to Navy Beans there will be DC-3’s/C47’s still making a living…
So if the hot air expands (uniformly over the whole earth of course) where is it going to go ? Seems like sea level air pressure won’t change much. And the thermal updrafts, should make take offs easier.
I never tried to take off down wind, but I did land down wind once. Talk about a lesson in aeronautics. The distance a piper Colt can travel down wind with zero power is quite astonishing.
Lie I said; I did it once !
I’d guess that by 2050 you’d be more likely to see the 737 MAX-8 than the 737-800 anyway.
Not just the AMS. When I see words “Center for Climate Systems Research”, I expect drivel. I have promoted the Columbia University to a Columbia High – no, Columbia Middle.
Had to be some good Columbian to get that high.
The once very useful Australian CSIRO has also degraded itself into just another CAGW tub-thumper.
Amen! What complete drivel. What will we be flying in 35-55 years? What were we flying 55 years ago? In 1960 the 707 and DC8 were king and queen with their huge capacities of 250,000 lbs maximum takeoff weight powered by four relatively scrawny 15,000 lbs of thrust turbojet engines. Compare to GE and RR motors of today with upwards of 90,000 lbs of thrust lifting takeoff weights over 1 million pounds.
I do remember a seemingly endless takeoff roll in a stretched United DC-8 loaded for a trip to Boston at the old Denver airport in the early 1980s on a hot summer day–we used all of that runway! Density altitude is of course a real consideration.
Oh, and aren’t the models (and the observed warming) more about higher low temperatures than higher high temps?
Shuffles off, muttering and shaking head.
There will be no further technical innovations in aerospace, and no more improvement in aviation propulsion systems. Guess I better start using up all those frequent flier miles ASAP.
brians356.
An interesting model.
You’re modelling on some climate model that has the Arctic ice-free with teeming wildebeest by December 2014, I guess.
One point not mentioned is the average weight of the future flyer.
My model has that at about 430-450 pounds – about 200 kilos – by 2060.
I’m using a GIGO/A5.BotE.guess-18000 model
[BotE – Back of the Envelope]
[18000 – amount of weekly grant I expect for funding from Friday. Sterling, but dollars would do]
Oh – Mods: – /Sarc actually.
I know you didn’t guess! [/Sarc^2]
Auto,
somewhat dischuffed that shysters in high office continue handing out money-pit content to plausible charlatans – and a few honest scientists, who want to but bread on the table.
No worries – we’ll have rechargeable electric airplanes by 2050; no carbon footprint you see.
I agree John, I used to fly for a living back in the 60’s and 70’s and back then there were a few airports round the world that were WAT limited, ie a/c weight, altitude and temperature. Tehran, Nairobi to name but two of the many. Takeoff from these were usually early in the nornings if you wanted a full fual load for the next leg. I cannot believe that any global warming will make the problem worse given that aircraft have operated all round the world with its great variation in temperatures for nearly 100years.
After 30 years I let my AMS membership expire for the same reason.
Did Boeing suddenly stop hiring Engineers?
Did that a while ago. “Last one out of Seattle turn off the lights”.
“…impact of extreme temperatures…
I stopped reading right there.
So they use a modelled output from ridiculous climate models?
Ok, in the modelled future I won’t model my life into an airplane again.
“Ok, in the modelled future I won’t model my life into an airplane again.”
Would that be in a “model” airplane?
I knew, I had forgotten something. 🙂
Hey, any landing you can walk away from is a good landing, as the old pilots used to say.
And no matter how gruesome the sight, I always walk away from my rc model’s “landing”.
Am I the only person who thinks this is utter bull sh*t? How do planes function at the equator where it is hot all the time? How did the Japanese and Americans ever manage to fight an air war in the Pacific islands during World War II? You just work around temperature, air density, and altitude restrictions, and if there is an economic effect, it is probably very little. If it costs more, how is that any different from what carbon taxes would add to the cost?
It’s not COMPLETE bullshit. Hot air is a bit thinner than colder air. But neither is it high quality work. Notice the lack of numbers? And the author’s apparent ignorance of the fact that warming seems mostly to affect Winter and night time temperatures, not afternoon high temps.
If you want to entertain yourself for a few hours or days, the math is available at http://en.wikipedia.org/wiki/Density_altitude#Calculation.
But even if the assumptions were correct — which they probably aren’t remotely, the impact would be that a few aircraft requiring a lot of runway at a few airports without a lot of runway — might have to fly with a few empty seats or a bit less fuel on a few really hot days. (FWIW, a 10 degree F increase in air temp is roughly the equivalent of using an airport 500 feet higher. e.g. Buffalo, NY vs JFK)
If the average temperature did get higher, the airports could also add a few feet to their runways to compensate.
So how much does the 0.79 degrees of warming effect the take-off length, 1 foot maybe a foot and a half
No Don the planes just sit on the runway till the temperature drops. Never fly empty… weather related you know.
I was wondering that – I was at the Phoenix Airport last summer when it was 115 degrees F, probably at least 120 out there on the concrete and asphalt runway, and I swear that I saw a long line of planes taking off, almost like they had been designed to meet just such a challenge. Maybe I was dreaming.
That can’t be true.
My model says so.
/sarc off
Sky Harbor Airport (Phoenix) did suspend takeoffs and landings for a few hours on a couple of days in June 1990 while the official temperature exceeded 120°F. I seem to recall it had something to do with some set of flight parameters were not available for temps beyond 120°.
That problem was subsequently remedied, but the Phoenix temperature has never exceeded 120°F. since.
By 2050, most aircraft now flying will be scrap. New models can have the relevant design features – bigger flaps, better braking systems, higher-rated engines designed for faster acceleration at low air speeds, more efficient engines requiring less fuel, hence a lower TOW. built in to cope with the change – if any – in airfield conditions. Another non-problem built out of FUD.
BTW. Now you’ve got your bionic ears, Anthony, have you given any thoughts to re-qualifying, just because you can?
“New models can have the relevant design features – bigger flaps…”
Or better flaps
http://www.businessweek.com/articles/2014-11-20/flexsyss-wing-flaps-promise-to-save-fuel
Well before 2050 aircraft will be significantly different. Fuel costs are the largest single operating expense of many airlines, topping 40% in some cases and 30% or above in many others (). More efficient engines and lighter airframes are already huge priorities at Boeing, and I assume Airbus as well. Using less fuel per passenger mile means making the same trip with the same manifest needing less fuel on board, which means lighter takeoff weight.
Airlines and aircraft manufacturers have to make progress on this front to stay competitive and keep air travel affordable, and the improvements already rolling out in current production will more than equal the trivial air density reduction from higher temperatures. “Climate change” considerations will make no difference to their efforts although likely PR departments will trumpet such nonsense loudly.
On the other hand, the increasing obesity in the US population, if it spreads worldwide will swamp these efficiency improvements and then some. I wonder if anyone has modeled that?
There should have been this link included in the above: http://www.aviationdb.com/Aviation/FuelExpenseByCarrier.shtm
In the late 19th century there was great gnashing of teeth and wailing over the horse manure problem in London and New York. So much so that an international conference was held in New York. People at the time just could not think what the solution was going to be. I think by 2050 we would have solved any take-off problems.
http://www.techfresh.net/wp-content/uploads/2006/12/sax-40.jpg
http://a.abcnews.com/images/Travel/ht_whale_plane_4_sr_140117_16x9_608.jpg
http://4.bp.blogspot.com/-9Ku3aTbj0Mc/VE5VTwINHGI/AAAAAAAAkME/xaYyr5qfblI/s1600/q.png
Why do future planes look more and more like fishes?
Contrari – I was thinking birds because of the wing shapes, but yeah, fishes. Good thought.
At high MPH the air acts as if it were a liquid.
Fish have evolved their shapes to move fast through a fluid. Aircraft have the same problem and the shapes will be much the same.
ConTrari
November 26, 2014 at 8:53 am
“Why do future planes look more and more like fishes?”
Why do current planes all look like tubes? Because that’s simple to build.
Blimey – a plane powered by LNG!
Auto
Is it just me, or does that second picture look like a Romulan war bird?
Rather like a Klingon Bird of Prey. 😉
I would not want to sit too far off the centerline of either of those ultra-widebody designs, nor any others!
I was going to mention the same thing – maybe the turning circle is measured in hundreds of miles in order to avoid having flying passengers inside a flying plane.
I think the manure problem we have now is even worse – CAGW and politician manure…
I discovered over at Bishop Hill :
“… in order to reach its outlandish picture of the future, RCP8.5 is forced to make some outlandish assumptions, most notoriously that the efficacy of carbon sinks will decline over time, despite the literature not actually supporting such a case. There are also some wild assumptions about energy use and population growth that have been documented elsewhere.”
http://bishophill.squarespace.com/blog/2014/11/27/a-right-royal-contradiction.html
I know of a private pilot who got into trouble trying to take off from a mountain airstrip on a hot day. He stalled it and came down hard. End of license.
I know of a private pilot who got his licence pulled for landing twice while forgetting to put down his landing gear. Some people have got a whole lot more money than sense.
I hate to tell you this, but private pilots are not all that well trained.
I beg your pardon! 59 years as a private pilot. 0 accidents. Common sense rules the day.
Agreed, 3 major crashes recently hitting my local news involving private pilots – local whole family killed when pilot lost bearings in a storm and crashed, local 4 men killed when float plane stalled on landing – plane was overweight as contributing factor, 2 men killed when pilot lost bearings in a storm. Sorry, I won’t fly on a small plane with a private pilot.
Speak for yourself. They get a darn side more training than the people we let drive automobiles.
We test drivers to make sure they signal before turning left or right. They are never tested for ability to turn left or right, and that is quite evident at any intersection.
Neither are those fledglings leaving the nest the first time.
The survival instinct kicks in strong though, and usually gets one thru the early stages.
It did for me.
Well-trained private pilots don’t all demonstrate good judgement.
40 years, 2 bird strikes on takeoff, both acts of God according to ATC witnesses, very glad no Center for Biological Diversity witnesses.
Either below minimum airspeed or AGW: run it by the folks at Columbia. I’m surprised the FAA would pull a ticket for it, though.
How many flights worldwide are delayed today due this phenomenon?
The physics seems logical. But are we so close that it will become a real problem?
Some days are quite hot in some places, even now.
Back in the 80’s I was on a plane out of Madrid. We had to wait for space on a longer runway because it was too hot to take off on the runway we had been originally scheduled for.
Back in the 70’s they stopped doing commercial flights out a small town in central BC because it often got too hot for the length of the runway and no one wanted to cut off an access road to make it longer. One of those little valleys where the temperature was frequently over 100 and trailer jacks often sank through the asphalt … Hard to make an asphalt mix that is good for -30 to +100.
Elevation (AMSL) of the runway surface is a larger effect. Whatr they gonna do ’bout that?
Since we’re told that sea levels are increasing at an ever alarming rate. Soon all airports will be engulfed by the rising waters, and have to move to higher and higher ground, further compounding the AMSL issue.
Yikes, truly is worse than we thought… wait, wouldn’t rising seas make the AMSL issue better?
This is when sea planes will come in handy.
Thanks for making my brain hurt (it doesn’t take much).
doesn’t rising sea level improve the takeoff conditions, by lowering the altitude of all airports? thus global warming is the solution to its own problem.
But if the sea level rises, all existing runways will be by definition, at a lower elevation relative to sea level. 🙂
Along this demented line of “modeling” sea level rise thinking pretty soon they will be in a panic about having to repaint/adjust waterlines on all the boat and ships in the world.
I would think a secure and inexpensive source of quality fossil fuels to actually run the jets would be more of a concern in 2070. Anybody ever land or takeoff from Lima Peru?
Try Quito, Ecuador. At approximately 7900 ft, the air is thin. If the planes can take off and land there, why should they have a problem elsewhere?
I recall flying back from Johannesburg to NY, which was fairly hot and about 5,500′ above sea level. The outbound flight had been non-stop but the return required a stop at the Cape Verde islands to reload more fuel since the maximum takeoff weight meant that we couldn’t take on a full load of fuel (it was a 747 as I recall).
Yes, I did several times and I will next Saturday actually. May I ask why?
Bogotá airport is 2600 m.a.s.l.. Lima’s Jorge Chavez is near sea level
Addis Ababa, Ethiopia 2440 metres, approx 8000 feet.
Went out of Ngari Gunsa (Ali County) airport in Tibet last year
Elevation 4273m and the half-loaded 737 took all 4700m of the runway
No problems – doesn’t ever get above 10 deg C there
I live in sight distance of a major wildfire refueling/reloading base at an altitude of 4800 feet. Watching a fully loaded air-tanker take off and do a slow climb-out on a 100° F (38° C) day is almost painful. I also monitor their radio transmissions. I have yet to hear a pilot request a partial load of either fuel or slurry due to density altitude. They use a bit more runway and don’t climb as quickly but get off the ground without a problem.
I have also left that same airport on regional commuter aircraft and heard the announcement that the airline would be awarding free miles to anyone who could wait for a later flight due to load restrictions on a hot day. I think the words here are what most “skeptics” have been trying to tell the alarmists for years “humans and nature adapt to conditions”.
And the very next article on my RSS : http://en.itar-tass.com/russia/763774 Siberian airliner passengers help push icebound jet to runway
I thought that was bad news to push, pull, or step on control surfaces?
I thought I read that Siberia was warming? The story said it was -52C on the ground, it’s not much colder than that at altitude?
Why would we need to adapt when we know that temperatures will be the same or lower than they are today?
FAR part 121 carriers operate under much more stringent rules in these areas.
its also good proof of why these reporting stations at airports cannot be used for climate models.
they deal with tarmac/runway temps as the FDC on aircraft need that temp to feed to FADEC for thurst adjustments.
used to work for business express then (buy out) amr-eagle at kbgr, our old a model saab 340 (turbo prop ge ct7-5a engine) were really bad in hot weather. the SF340b model (ct7-9b engine) and then the embraer 135/140/145 were not as bad.
Ding, Ding, Ding!!!! We have a winner. The airport temperature stations are sited to give accurate data to pilots for air density takeoff calculations. They succeed when they either accurately reflect the air temperature over the runway, or slightly overestimate it. Nobody will died if you calculate your takeoff conditions with a higher than actual air temperature. But these same stations should be very suspect for use in climatic measurements. As airports are expanded and runways widened, the temperatures will go up in ways that have nothing to do with climate, and everything to do with microclimate.
As a weather observer in Canada who has worked at a few different airports and used to preflight brief pilots, i can tell you with near certainty you will not find a metar who’s temp is anything but ambiant temp over a grass area away from pavement. Perhaps some airports put runway surface temps on the ATIS but none that I know of. It sounds like it would be good data to have available though.
The desperation is getting more and more hilarious. How stupid can it get?
Please don’t ask that question. I really don’t want to see the answer.
He made it sound like a challenge, didn’t he?
The sky is the limit… or so I thought.
Einstein postulated that there is plenty more.
Why would meteorologists care about calculations done by thousands of pilots every day? If it was a problem for the airline industry you’d expect the paper to come from them.
Here’s another thing they could worry about: higher density altitude wrecks the single engine performance of light twin-engine aircraft. This could lead to more off-airport landings – much more scary than restricting take-off weights. Cue paper.
The ‘Alarminati’ at work.
Ok. I guess Lima is not that high, but there are plenty of functioning commercial airports at over 2000 metres…
There are plenty:
http://en.wikipedia.org/wiki/List_of_highest_commercial_airports
Winner is Daocheng Yading Airport, China at 4,411 m (14,472 ft). I always thought La Paz was the highest airport at 4,061 m (13,323 ft), but China has four higher than that. The Wikipedia page claims their list (28 commercial airports higher than 2,500 m) is incomplete, so I guess there are more. Twelve are in China, one in India and the rest in South America.
Echoing Matthew W further down, this airport list just confirms that climate change will hit developing countries hardest.
(/sarc, if anyone needs it).
Per the peerless Wikipedia [so accurate that I can edit it . . . .]: –
Mexico City International Airport. Latin America’s busiest airport by traffic movements, has an Elevation AMSL of 7,316 feet / 2,230 m
At Dry Adiabatic Lapse Rate, that is about 20C cooler than a Virtual sea-level MEX.
And I remain much more scared of the cold than the putative 0.8C of heat that we will all get – per some good folk – by twenty whenever [after they have retired is that? Possibly, I don’t know their circumstances].
Auto.
Not being a scientist, can some one explain to me what exactly is 200% ?
When I learned basic maths at primary school percentages were expressed in one hundreds.
I hope these climate “scientists” are not designing aircraft.
Many people throw around percentages in a misleading fashion, I find it easier to think of it in terms of the the fractions: 50% is 1/2; 100% is 1/1, and 200% is 2/1.
for discussing increases to an original amount:
an Increase of 50% means you have your original amount, plus 1/2 again, for a total of 1.5 times the original. an increase of 100% means you have the original amount, plus an amount equal to that, so that you end up with two times what you started with.. An increase of 200% means you have your original amount, plus an amount equal to twice that amount, so you end up with 3 times your original amount.
You can see how that can quickly get counter-intuitive if you’re not careful, which is why people who want to slant things find it so easy to muddy the waters by using unexamined percentages instead of actual numbers.
My guess is, to some people an increase of 200% sounds like a whole lot more than 3 times as many.
Without knowing how many weight restriction days they are currently having and the full impact of a weight restriction day I don’t know how to advise them…If they were looking for my advice.
“evil always takes advantage of ambiguity”
GK Chesterton
Say there are 20 load restriction days (LRDs) per year and you predict a 50%, 100% and eventual 200% increase in LRDs over the starting year in the coming years. Say also that in the following year LRDs go from 20 to 30. That is a 50% increase over the start year or 100*(30-20)/20 as in 100 times (this year – start year)/start year expressed in percent. The next year it goes to 40. That is a 100% increase over the start year or 100*(40-20)/20. At 60 days it is a 200% increase or 100*(60-20)/20.
At least they didn’t express the result in equivalent Hiroshima atomic bombs of heat.
Hot, High and Humid…that’s the mantra for determining whether to take off or not. Here in Colorado, humidity isn’t such a problem but hot and high are. Each summer, there are several accidents because of density altitude stalls. Of course in the winter we have the problem of icing with similar results. Humm, maybe with “””climate change”””” we won’t experience planes augering in because of icing in the winter.
(and if you need a >>>sarc<<<< tag there it is.
Mike
Early 70’s, Stapleford airport, 707, very hot day — our takeoff run went on and on and on at which point I was thinking OOH Crap, then we hit a dip in the runway which seemed to launch us off.
So how many flights have been aborted because of global warming? How many flights need to be fueled to maximum weight that must takeoff from high altitude airports in the heat of the hotest days? It is probably less than the number of people who have lost their lives climbing Mt. Everest.
More what-if scenarios based on a faux-science fantasy? How refreshing.
Because jets are taking off with no runway to spare? How desperate for a publication can they be? That’s the real scientific curiosity here.
Anyone see the Boeing Dream Liner land at the small private airport in Wichita last year by mistake? It took off on that runway, one of half the desired length.
Empty, no doubt, with minimum fuel. –AGF
They stripped out all the seats and interior furnishings. No passengers or luggage, and just enough fuel to make it to the correct airport which was just 5 minutes away.
35 minutes worth then – 5 minutes plus the legal VFR reserve.
Being light means both higher acceleration and lower take off speed.
Actually it was a modified 747 freighter, used to carry 787 parts, known as a “Dreamlifter”.
Soon after a similar thing happened to a passenger 737.
Obviously they’re referring to model planes trying to take off in the model climate, real planes in the real climate will not be affected.
Or they’ve been sniffing model glue.
How about we just model the planes are filled with nanotube conductors instead of copper wires and save 2 tons of weight.
Antoinette points out that most of aerospace industry still uses pure copper wire for its conductors — virtually the same copper wire used since the 1850s. His company’s nanotubes could replace this material with better conducting nanotubes, which weigh a mere 20 percent as a much as the copper wiring per volume. Antoinette adds, “Copper wire is still the conductor of all our satellites, all our aircraft.” He points out that a current 747 jet has two tons of copper wire aboard — a weight cost that could be cut in half by the use of nanotubes. He says, “you’re talking literally millions of dollars of savings in fuel costs over the life of an airplane.” – See more at: http://www.dailytech.com/Sheets+of+Cheap+Carbon+Nanotubes+Now+a+Reality/article10927.htm#sthash.HAJzWtVN.dpuf
The newer generation Airbus aircraft and the Boeing 787 actually use aluminum for their power cables to achieve significant savings in weight.
[emphasis mine]
I do not see them saying the observed increases in surface temperatures caused any problems, just that their “observations” were temporally equal. UHI anyone?
Pilots, what regulations changed in this time frame? Standard flight procedures? I haven’t read the paper but I’d like to know why the restrictions were in place along with the factors that went into the decision. Fuel costs shot up dramatically in this time frame thanks to our pal Jimmy Carter. Since it takes more fuel to get to Vr and maintain a safe V2 in higher temperatures, and the greatest fuel use is at take off, I can imagine a closer look at the economics after the “arbitrary” date of 1980… regardless of an airport’s “climate change.”
Add two feet to the runways every year and they should be OK. –AGF
agfosterjr
November 26, 2014 at 8:18 am
You are right, of course, but the [wait while I am thinking of an elegant way to say something a tad uncomplimentary] – ahhh – carbonistas will politely suggest that the extra two feet will need to be manufactured or excavated – and then trucked, at most [Non-adjacent to the sea, nor rail connected] fields. And then, laid to last . . . .
Oh dear.
All those plant foods emitted.
But surely – mitigation and adaptation are our guiding lights. As you rightly imply.
Mods – it’s me.
/SARC [I think I have other modes, but the ‘S’ one does pop up, mmm, from time to time. When near a keyboard, say!]
Auto
In the stark light of reality, why?
Using RCP 8.5 is a bit ludicrous. That pathway assumes that several times more coal is burnt, than is in reserves.
Les, I agree with you that using 8.5 is absurd. I used to think so for the very reason that you gave. However, I discovered that I had been mislead by our Green friends behind ‘the Club of Rome’. Official reserves are a small fraction of the amount of resource available. Resources are what’s there. Official reserves are defined by regulation and law, and include assessment of economic feasability of recovery. (This distinction was specifically not made in that alarmist tome.) That assessment changes with every technological advance. Reserves are less than one twentieth of resources. So there’s no problem with burning more fossil fuel than we have in reserves- we’ve already done that several times over.
The reason I see using 8.5 as absurd is that it’s at the alarmists high end, unlikely even in their view. And thats not taking into account the ever increasing evidence for a much lower climate sensitivity.
Good Lord! I had a PPL long ago and gave up when my hearing went. I nearly lost it at Windhoek airport one hot sunny day. I was flying solo in a Cherokee 140 and about to depart for Cape Town when the tower asked me to use the short runway. No problem and off I went. I did have full fuel tanks. The end of the runway was fast approaching and I couldn’t lift off. I remember my instructor, Ernst Stogmuller, who had demonstrated a short take off once. Nothing for it. Full flaps and the little Cherokee jumped into the air. Keep the nose down and EASE OFF the flaps as speed increased and I cleared the earth bank at the end of the runway. Phew!