'Green' Flying, computing, deforestation or whatever else is as valid as "low fat" Sausages, pizza, lard or geordie "bairns". The only reason you need to say "green" is because it's anything but....

One day we will either be technologically advanced enough that none of this matters, or, in the alternative, the planet will be flying around the sun like Mars, dead so far as we can tell.

In the meantime we should just get on with it. Funding for technological advancement is probably a good bet though. And no, not fish food powered aircraft. I'm talking about real technological advancement...the kind that makes Industrial Light & Magic CGI look like a bunch of egg cartons glued to MDF.

Beardy Branston won't get us out of the pickle...he just wants to get publicity "Hi I'm Richard, you know I'm against global warming because I've always been famous for wearing chunky jumpers....a kind of straight, thin Russell Grant with more money and my own teeth..."

Why do you have to polarise the issue?

Yes, the extreme ardent greenies want to ban all fires and walk everywhere wearing organic non-leather sandals, and the extreme ardent technophiles want to travel everywhere in super-advanced energy hungry personal hypersonic flying hovercarcopters.

In between, there are many of us who advocate measured, intermediate action.

The aviation industry was given tax breaks from its inception because the cost was so high -- it would not be disastrous for the economy if short-haul flights had the same fuel tax per litre as commuter trains. Those of us who don't fly out to Prague for a romantic weekend every few weeks are not dying of stress and still maintain perfectly healthy sex lives. Our society would not collapse if on-demand road deliveries were scaled back and more freight shuttled cross-country on overnight trains. Has the congestion charge destroyed London's economy or simply wound up a minority of the public while reducing the level of smog?

Join us in the middle ground. The air's clearer and life goes on as normal.

You mean Russel Grant isn't straight? Say it ain't so!

Well, not necessarily. It would definitely mean a rebalancing of what we grow and where.

But then, we currently grow huge amounts of tobacco, opium, hemp and other non-edible (generally) crops - acreage that could be shifted to other crops.

Or perhaps we should look to create biofuels from tobacco, opium and hemp, so that the drug-related uses for these crops find a "shortage" as their consumption for biofuel production skyrockets.

Dude, srsly, WTF!? Two tonnes of CO2? Is anyone else's mental back-of-an-envelope calculator flashing up "Does not compute" here? Given conservation of mass, doesn't this mean they're claiming that between landing on the ground and finishing taxiing up to the gate, the jet has burnt a ton of fuel? Someone has to have dropped a decimal place here, surely.

Stop nancying around with stars and CERN and start working on cold fusion and teleportation devices.

Damn slackers.

Mine's the one with the Nahquadah generator in the pocket.

I like how El Reg has managed to turn a safety story into an environmental meanness story. How many people would think "Oh, cool, the nose gear's collapsed. Oh well, at least we saved 2 tonnes of CO2"?

Landing gear and engines are two of the more critical components of aeroplanes. I think that Virgin dropped what appeared on the surface to be a good idea, but which was in fact, a load of old horseshit, is a sensible move for them to take.

But the environmentalists (emphasis on the last three syllables please) don't see things rationally like that.

Paris, because she's in orbit around Planet Fairy like most of the Greens.

No, I would tend to believe the 2 tons figure. Jet engines are designed to be most efficient at high altitude, and a disproportionate amount of fuel is burned when on or near the ground.

The "towing to the end of the runway" thing *is* important, because the NOXs which come out of a jet are a real ground level pollutant. When I spent a while working airside at Gatwick (our portakabin was just next to one of the main taxiways) I went home with a headache every day from the poor air quality.

I wonder what the "working assumptions" were in the BAA study showing that pollution levels with the third runway at Heathrow are still within permissible limits. I wonder if they had assumed that planes would be dragged to the runway with the engines off?

if someone's got "guilt" then maybe they shouldn't be flying. If they're so "green" then they should stay home, live in their organic commune, sing kumbaya and come up with other politically motivated, unsustainable "green' enviro-horror scams.

Instead I see all over, H2s and SUVs and huge trucks driven by short women and single guys, who vote for morons supporting "glo-bull warming" shite. People go to protests and join the anti-American propaganda teams and then drive home in their 5MPG monsters.

All we need to do is get those hypocrites who violently and loudly support "green" agendas to actually live those "green" lifestyles and give up the non-carbon-neutral elements of their so-called lives. That alone would save more energy and "environment" (is there a unit of "environment" that can be "saved"?) instead of them trying to force others to do what they will not. "Guilt" doesn't save anything, and I'm tired of enviro-nazi's claiming "guilty feelings" while wasting energy on lavish lifestyles, as if "guilt" makes it all better.

It's all economic manipulation by external forces anyways, taking advantage of the passive-aggressive, sadistic, sociopathic nature of many liberals. Claim to be "non violent" but use the law and the Media to hurt and control as many people as possible in order to satisfy their own personal ideals.

Mine's the leather one with the keys to the supercharged, mid 70's V-8 Holden Police Interceptor.

AC Sez

>> Those of us who don't fly out to Prague for a romantic weekend every few weeks are not dying of stress and still maintain perfectly healthy sex lives.

A Sex Life? Pics, or it never happened.

Just like Paris really...

"Correctly chosen/engineered strains of algae would perhaps be able to draw their carbon primarily from atmospheric CO2, rather than from artificial fertilisers;"

I thought it was nitrogen and phosphate that came from fertilisers?

"..after aircraft builder Boeing determined that towing loaded airliners significant distances on the ground would seriously affect the lifespan of their undercarriages."

Simple solution. Get everyone off the plane, a big Geoff Capes style tow-rope, and get everyone to pull the (then unladen) airliner to the runway.

Jolyon

Paris icon, because I'm sure her undercarriage has been subject to excessive stress too.

Is it me or has this been slapped down before it got near started.

Reinforce the gear? put the nosewheel in a sled.

tow from a different point?

persoannly i'd like to see it go all the way and have aircraft launched with engines off/idleng using a electromagnetic catapults

of course we'd need alot of electrical energy for that, and therefore we needd a bit more investment in fusion...

Hmmm.. maybe we should mandate that all future planes must have suitable towpoints fitted to the chassis...

Hmm, I pretty much agree with you. What alarms me is that I'm a liberal doing so - with friends like these...

Maybe liberal isn't the right term. Maybe I'm a 'progressive'.

Right, then. I like my politics like I like my trance music - progressive, and spun by Armin Van Buuren.

Or something. Whatever.

"But then, we currently grow huge amounts of tobacco, opium, hemp and other non-edible (generally) crops - acreage that could be shifted to other crops."

But much of that acreage is not very suitable for growing food crops.

Also, with enough hemp, you can fly without worrying about fuel !!

This icon is *NOT* the smiley face found on various ingestible substances that, purportedly, give better "flight characteristics" !!

Priceless!

200 years from now someone will write a learnéd dissertation (in PsychoSociology, what else):

"Perceptions & Perplexions Of The Wor{l}d -- The 21st Century As Seen Through The Sub-Headings Of El Reg".

or perhaps

"Encoding The Event -- Reality And Obliquity in El Reg"

"...an as tight-knit as it was outspoken community of IT samurai thriving through the smoldering flames of the Grand Decline of the Information Ache, &c &c"

[But that's just the intro. After that, it will be solid multivariate analysis of El Reg wordings and verbiages, with the result that practically every extracted factor is significantly orthogonal to every other one. (AND to The World, possibly).]

"I thought it was nitrogen and phosphate that came from fertilisers?"

Well, allegédly (saw it on TV) in England they put soot on rosebeds...

But then, that's in England...

(The fire icon, to make more soot for fertilizing England.)

Sorry, but wont work.

The whole way an aircraft functions is by a combination of forces on the aircraft, these are thrust, lift, drag and weight. In cruise they balance out nicely so your aircraft stays in the air and maintains a nice and comfortable speed. On the ground, the thrust from the engines still produces lift on the wings and this lifts the aircraft slightly off the undercarriage thereby reducing the weight felt by the undercarriage.

Hence, by dragging the aircraft around the whole time without the engines running, you add a significant amount of weight that the undercarriage has to carry and which it hasn't been designed to carry whilst in movement. This leads to an increase in fatigue, and fatigue is what limits the life of aircraft.

At present, fatigue limits for your undercarriage are known based on huge amounts of simulations, calculations, stress data and fatigue testing of the aircraft/undercarriage systems (completed over years and years of testing), but the moment you start dragging them around this changes and where before you might have thought you only needed to check for cracks every 500 landings* you now have a crack forming and reaching critical length in under 500 landings, this means your undercarriage will fail, the aircraft will crash and people will be hurt/killed. This is generally considered a bad thing.

*figure pulled out of my ass for lack of desire to go searching for the exact figure

So whilst it may be an idea for future aircraft to be designed with undercarriage that are rated for this sort of activity it is impractical for in service aircraft.

Oh and before some one suggestions recalculating the fatigue limits - this is not an easy task, it takes years to do. The C130J Hercules fatigue test aircraft is STILL undergoing fatigue testing as we speak (24hr a day cycling for years on end) and how long has it been in service?

"Simple solution. Get everyone off the plane, a big Geoff Capes style tow-rope, and get everyone to pull the (then unladen) airliner to the runway."

Excellent idea; should help with the obesity crisis too!

"...On the ground, the thrust from the engines still produces lift on the wings and this lifts the aircraft slightly off the undercarriage thereby reducing the weight felt by the undercarriage..."

... is arrant nonsense.

Wing lift is produced by air flowing over the surface of the wing. Determined by the *speed* of that airflow and the area and cross-section and attack angle of the wing. The amount of "thrust" generated by the engines is irrelevant, the speed of taxiing (and therefore airflow over the wings) insignificant, and jetwash is not directed over the lifting surfaces, so that gas-speed is also irrelevant. Yes the wings might provide a *tiny* amount of lift at taxi speeds, but that lift would also be available if the taxi speed was attained by *towing* since it's the motion of the wings through the air that provides it.

You're right, though, that the fatigue factor is the limiter. While you see planes being nudged around near the apron or hangers by little tenders hooked up to the nose wheel, practical taxiing speeds are *much* higher, and the stress imposed on the nosewheel commensurately greater. It's not the vertical force exerted by the mass of the plane in earth's gravity field that's the problem, it's the horizontal force towards the aircraft's nose at taxi speeds that has not been accommodated in the aircraft design.

One place, though, that *should* be able to support large amounts of forward impulse is the engine mounting strut on planes that have them. A towing yoke/cable looped around that should be able to do the job.

Good point. Unfortunately, not all aircraft are jet-powered. The egg-beaters that shuttle between Southampton and Dublin (among other places) have ruddy great fans in front of the wings.

The propwash provides negligible lift. If you could get lift that way, there'd be no need for complicated helimocopters, would there? Just add another engine outboard of the first and you've got airflow over most of the wing surface, and a levitating plane... None of this chancy rotorwing nonsense.

You can stand up in propwash. It doesn't go fast enough to provide significant lift at 0 angle of attack.