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Trans-Atlantic flights are often 90 minutes of flying time from a suitable runway. Trans-Pacific flights can be 3 hours or more of flying time from a suitable runway. Needless to say, airlines cannot glide with no power for hours. Air Canada Flight 143 (see http://www.wadenelson.com/gimli.html) was estimated to have a glide ratio of 11:1 with both engines windmilling. So from 40,000 ft, the maximum glide distance would have been about 100km. Sink rate was estimated at 2000 ft/sec meaning with all engines out, you will be visiting some destination at sea level within about 20 minutes.

Gimli Glider.

So the claims they used to justify the ETOPS changes were that the chances of losing two engines was one in umpteen millions. I know there was one due to loss of oil back in about 1983 and I think there's been another since then. I don't count the Gimli Glider because that was a fuelling issue, but I'm still happier with four engines than two.

Apart for the Gimli Glider ( http://www.wadenelson.com/gimli.html ) it went pretty smoothly.

Of course it would be utter carnage in the skies over (or on the landings in) the United States.

and let's not forget about the boeing 767 that ran out of fuel at 41,000 feet because of a faulty fuel gauage and a pilots math mistake.

You can get off your high-horse Mr. Pilot-Man..

http://www.wadenelson.com/gimli.html

And I quote:

Flight 143's problems began on the ground in Montreal. A computer known as the Fuel Quantity Information System Processor manages the entire 767 fuel loading process. The FQIS controls the fuel pumps and drives all of the 767's fuel gauges. Little is left for crew and refuelers to do but hook up the hoses and dial in the desired fuel load. But the FQIS was not working properly on Flight 143. The fault was later discovered to be a poorly soldered sensor. An improbable sequence of circuit-breaking mistakes made by an Air Canada technician independently investigating the problem defeated several layers of redundancy built into the system. This left Aircraft #604 without working fuel gauges.

[WTF! they flew without working fuel gauges?!?] ....

The flight crew had never been trained how to perform the calculations. To be safe they re-ran the numbers three times to be absolutely, positively sure the refuelers hadn't made any mistakes; each time using 1.77 pounds/liter as the specific gravity factor. This was the factor written on the refueler's slip and used on all of the other planes in Air Canada's fleet. The factor the refuelers and the crew should have used on the brand new, all-metric 767 was .8 kg/liter of kerosene.

[pesky unit conversions] ...

As Pearson began gliding the big bird, Quintal "got busy" in the manuals looking for procedures for dealing with the loss of both engines. There were none.. Neither he nor Pearson nor any other 767 pilot had ever been trained on this contingency.

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Hmmm. Now.. the crew *was* able to deal with this (and this was really quite a remarkable landing. The flight crew should most definitely be commended).. but *not* because of their training from Air Canada but because of extra-curricular activities.

Berj

The jet liner to which you refer, I think, is the Gimli glider which, through a forehead-slapping number of independent goofs, ambiguities, and misunderstandings made by a frighteningly large number of people, ran out of fuel over Cananda in 1983.

Gimli Glider

Remember the Air Canada Boeing 767 that ran out of fuel? Story at http://www.wadenelson.com/gimli.html

The reverse situation actually happened in New Mexico. A nuclear device got TOO hot. As part of Project Plowshare, operation "Gasbuggy" was an underground detonation of a nuclear fission device to see if it natural gas would be released from the surrounding rock strata. The test didn't go exactly according to plan. I quote from the web site:

QUOTE

After a number of dry runs, a canister containing the bomb and associated hardware was lowered into the 4200' well and the hole cemented shut. Within hours, a water pump at the bottom of the well quit working. This caused an air conditioning system cooling the bomb to flood and stop working. The temperature at the bottom of the well soared to over 200 degrees. Workers abandoned the site because no one, not even the lab scientists knew what might happen to a nuclear bomb drowning in boiling water. All the public knew was that the test was "delayed."

After several nerve-racking weeks lab employees crept back into the area. After taking some readings they made a decision to try and set the bomb off. Everyone was cleared from the area. Spectators were kept more than five miles back. Holcomb and other managers moved to a command tent for the countdown, the result of which was, at that point, anyone's guess.

The bomb exploded. Closed circuit television cameras on site recorded a seven foot ground wave--the ground and trees and everything in the vicinity rising and falling like an ocean wave. Two and a half miles away from the blast Holcomb and the others were thrown from their folding metal chairs when the wave hit.

UNQUOTE

More information about Operation Gasbuggy can be found here:

Gasbuggy

True, and for a real life example, the Gimli Glider (a 767) (an excellent read, by the way) had a glide ratio of 11:1. 13,700 feet would provide a possible glide distance of 30 miles.

already happened: see the gimli glider story

The RAT is the Ram Air Turbine, a propeller driven hydraulic pump tucked under the belly of the 767. The RAT can supply just enough hydraulic pressure to move the control surfaces and enable a dead-stick landing. The loss of both engines caused the RAT to automatically drop into the airstream and begin supplying hydraulic pressure.

The Gimli Glider used this to survive the loss of both engines.

Airliners have optimal glide ratios of 25 to 1. An airliner will certainly not soar like a glider (i.e. it has a low "soarability"), but it will be able to glide.

For instance, there is the case of the Gimli Glider, a Air Canada 767 that was forced to make an emergency
landing due to running out of fuel. At the time of the failure, it had a glide ratio of 11 to 1, which enabled it to glide for 12 miles to make a safe landing.

Of course, the pilot co-owned a glider...

Probably any intelligent person could figure out this convoluted explanation of aerospike engines. But few will bother, because it is convoluted. Perhaps you need all the history and technical background to understand the fine detail. But a good writer would start out with some kind of superficial explanation, so the reader can get some sense of why this material is important and acquire some kind of mental handle before plunging into the hard stuff.

The links in the ScottKin's original submission are even less impressive. Garvey just issues a press release talking about how cool their aerospike engine is, without the tiniest hint as to WTF an aerospike engine is. (Yeah, that will make people take notice!) The "California Space Authority" (someone's read too much Jerry Pournelle) site tries to explain, but utterly fails. And the Boeing site is most pathetic of all, with its pound-feet and square inches. I mean, I can understand that its politically impossible to metricize the U.S. consumer. But these guys are supposed to be the world's leading aerospace engineers! Yet decades after the rest of the world has gone metric, and after screwup after screwup after screwup in metric-English conversion, these "rocket scientists" refuse to modernize their measurements. Is it any wonder the rest of the world thinks we're a bunch of arrogant assholes?

Now by 1822, the U.S. had ceased to be part of the British empire (at least in our own minds), so traditional measures remained in use. We've cut way back, but we still have two kinds of gallons: the liquid gallon (which is the same as the English "wine gallon"; 231 cubic inches) and the dry gallon (same as the English "corn gallon"; 268.8 cubic inches).

Painfully complicated, no? I've always thought this kind of confusion is the real reason the metric system drove out all the competition. We were all told in school that the metric system triumphed because it's more logical and simple: you have a few basic definitions, and everything else extends from them in a simple way. But people don't mind complexity, if it's the kind they're used to. Not being able to communicate is another matter. Which is why Europe, with its thousands of diffent units of measure, embraced the metric system, but rejected all the similar reforms that came out of the French revolution (the decimal clock, the "rational" calendar).

And it's also why Americans have so thoroughly resisted metric reform. The "customary" system is familiar, the "logical" metric system is confusing. It's probably not that big a deal for American consumers; it just means we sometimes have to convert unfamiliar units. But it's totally unacceptable that any engineering gets done in customer units. It makes for lost space probes and airliners with fuel issues.

You mean like this:

Gimli Glider

See, planes can share a strip with autosports......

Here's my token plug for Canada ...

An abandoned airfield at Gimli, Manitoba, saved the lives of dozens of passengers in 1986, when a brand new Air Canada 767 on a flight from Ottawa to Edmonton glided to an emergency landing after running out of fuel in mid-air. The 767 calculated fuel in metric units, unlike most older aircraft, which confused the flight crew and resulted in an inadequate fuel load.

Ironically, the crew that Air Canada sent to recover the aircraft got lost on their way to Gimli and ended up running out of gas.