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OpenLearn Live: 2nd December 2016

Updated Friday, 2nd December 2016

Ice falling from planes isn't an urban myth - it can be more dangerous than that. Plus how Victorians saw Shakespeare. Learning and research from across the day.

OpenLearn Live opens the doors on the advent calendar of online learning and researcg to find the best hidden chocolates of... knowledge or... look, you know where we were going with this. This page will be updated across the day.

Yesterday, we opened some online advent calendars, marked World Aids Day and found the link between the five pound note and the Mary Rose

On this day last year: UK involvement in Syria; the only Mexican in space and Open Access

See the complete collection of OpenLearn Live

Today's posts

Shakespeare by Victorian artists

Are you a fan of Shakespeare? Are you a fan of Victoriana? We may have the thing for you...

Edward Prince of Wales, son of Henry VI – From a Seal in Sandford’s ‘General History’ Creative commons image Icon Victorian Illustrated Shakespeare Archive by Michael John Goodman under Creative Commons BY 4.0 license

Michael John Goodman has just set live a massive collection of Victorian images culled from Shakespearean texts. They've all been given a Creative Commons licence, and there's everything from "poor Jack, farewell" to "sleep dwell upon thine eyes".

Dig into the collection

Explore the mystery of Shakespeare's sonnets

Invasion? What invasion?

2016 hasn't been a great year for certainties. And - according to UCL - there's another certainty under threat, as the long-held scientific acceptance that invasive species are a danger to native flora and fauna seems to be under attack:

In the science journal Trends in Ecology and Evolution, conservation biologists Dr James Russell (University of Auckland) and Professor Tim Blackburn (UCL Genetics, Evolution & Environment) say scientific evidence on invasion biology is under attack, with much of the opposition value-based rather than science-based.

Their research showed a rejection of established scientific fact along with an attempt to re-frame, downplay or even deny the role of invasive alien species in global environmental change.

“Currently there is a lot of talk about living in a post-truth world, and, as scientists, we don’t want to appear precious or to overreact. But we do see a manufacturing of scientific controversy on an issue where, in fact, no controversy exists,” Dr Russell said.

“Instead, there is and has long been a consensus between the world’s leading ecologists on harmful effects of invasive species and this is not in dispute – at least not among the vast majority of scientists.”

The team cites recent articles in high-profile international news outlets such as the New York Times, New Scientist and The Economist questioning the science of invasive species management.

Read the full report at UCL: Worrying denial of invasive species threat

The challenge of invasive species

Great news for all our readers

For a while now, we've been working on something huge. It's still a work in progress but - on Wednesday - we'll be sharing the first step towards an exciting new look for OpenLearn. We'll be keen to hear your views.

Ice pack: Blue ice

This week, we've started off each day with a glimpse into the world of ice. Here's what we've featured this week:

We're finishing the week with something a little more man-made. Blue ice. Ice which starts in things like this:

Continental Airlines 737-300 Creative commons image Icon Aero Icarus under Creative Commons BY-SA 4.0 license A Continental Boeing 737-300 similar to one involved in a blue ice incident in 1989

You may have assumed that blue ice - ice falling from plane toilets and smashing to the ground, causing death and destruction - is something of an urban myth. Indeed, Mythbusters, who make a business out of sassily dismantling myths, may have given you the impression that this is a thing that doesn't happen:


But while planes aren't deliberately dumping the dumpings over your heads, blue ice does happen.

First of all: why is it blue?

That's because aircraft toilets use a liquid to disinfect, mask the odor and prevent freezing of the waste we put into them. And the liquid is governed by strident regulations.

So the waste from planes is blue, and planes don't come with a flap to allow pilots to eject it. How, then, do blue ice incidents happen?

The answer is "accidentaly" or, more scarily, "because the plane wasn't properly maintained." Slate records a couple of incidents:

Waste can seep out of the tanks in a malfunctioning aircraft. This happens when a sewage tank or drain tube develops a leak, usually resulting in what air travel experts refer to as “blue ice”—which is what you get when the blue waste treatment liquid from a plane toilet is exposed to freezing temperatures at high altitude. Blue ice typically gathers and stays on the outside of the aircraft, but sometimes it breaks off before landing. When blue ice does come loose, is often melts and evaporates before reaching the ground. This isn’t always the case, however: One Leicester, England couple was reportedly “enjoying a spot of good weather” out in their garden when some blue ice hit the roof of their house, broke apart, and landed on their heads. The husband said the ice gave off “a particularly pungent whiff of urine” as it began to thaw. (The blackish-green, oily substance that fell on the Long Island couple does not match common descriptions of blue ice.)

Obviously, the idea of chunks of icy poop whizzing out of the sky is disturbing - but it's quite rare. BBC News gathered some reassuring statistics in 2009:

And for a person to be hit is extremely rare. Out of three million flights in the UK in the past year, there were just 35 reported cases of ice falling. And in the 40 years the CAA has been recording such incidents, there have been just five cases of a person being hit.

And if you are unlucky enough to be hit by a piece of ice crashing out the sky, it's just as likely to be from some other system using water in the plane. It'd still hurt, but you'd be spared the smell of wee.

It's not people on the ground who would have had cause to worry, though. The ice leaving the plane presents more of a danger to the plane itself - as a 1990 report from the US National Transportation afety Board observed:

The National Transportation Safety Board is concerned about the potential for damage to airplanes resulting from ice ingestion into engines and impact damage to the airframe. The Safety Board notes a history of ice-related incidents resulting from the formation and subsequent release of ice around or near ground service panels.

On April 30, 1974, the No. 3 engine separated from a National Airlines Boeing 727 while in flight 60 miles east of El Paso, Texas. A Safety Board investigation determined the probable cause of the separation to be a firststage fan blade failure, which caused a sudden stoppage of the engine. The fan blade failure was probably caused by the ingestion of lavatory ice that had accumulated around a ground service panel near the forward lavatory drain outlet.

On April 16, 1985, an American Airlines Boeing 727, experienced an in-flight separation of the No. 3 engine while cruising over Las Cruces, New Mexico. The probable cause of the separation of the engine was again found to be the ingestion of lavatory ice and subsequent sudden stoppage resulting in the breaking away of the engine.

On January 16, 1989, a Boeing 737-300, operating as Continental Airlines flight 137, was diverted to Des Moines, Iowa, after an in-flight engine shutdown. The flight ended without injury to passengers or crew. Examination of the CFM 56-3 engine, manufactured by CFM International, revealed that a first-stage fan blade failed, which caused the engine to vibrate. A metallurgical examination indicated that the blade failed because of "soft-body" impact damage. Results from the investigation indicate that the engine ingested frozen blue lavatory fluid ("blue ice") that had been leaking from a lavator,y service panel forward of the engine inlet.

The engine manufacturer has documented at least 10 prior occurrences of ice ingestion into CFM International or General Electric engines. These occurrences began in November 1979 and involved Boeing 737-300, McDonnell Douglas DC-IO, and Airbus A300 airplanes. Most of the occurrences were recorded at cruise condition and at altitudes from flight level 290 to flight level 350.

And this is why, nowadays, reports of ice falling from planes have become rare - it's not the ice that reached the ground that was the threat, but the ice which smashed back into the plane - and that focused minds on finding a solution. Blue ice wasn't an urban myth, but it was a design challenge.

Explore plane design and engineering





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