source:::: bbc .com….travel

Natarajan

On a gusty March day in 1969, the future of air travel was revealed.

A spontaneous burst of applause could just be heard over the deafening roar of the plane’s four giant engines as they sped the sleek aircraft into the sky. Twenty seven minutes later the screech of wheels and a whoosh of a parachute, signaled the end of the maiden voyage of Concorde, one of only two supersonic passenger planes to ever fly.

When the slender, beak-nosed aircraft entered service seven years later they whisked champagne-sipping passengers across the Atlantic in just three and a half hours. The twenty craft went on to fly routes for another 27 years to South America, Malaysia and beyond, proving a hi-tech vision of glamorous, fast-living. But it all came to an end in 2003, when the fleet was retired over concerns about high operation costs, limited demand for the expensive tickets and the jets’ safety, following a deadly crash three years earlier.

But supersonic, commercial air travel still holds an allure for passengers, pilots and engineers alike. And now, with the help of modern materials and advanced computer simulations, aerospace researchers hope they will be able to overcome some of the issues that Concorde faced, providing a blueprint for the next generation of supersonic planes.

Big bang theory

Two of the main problems facing any supersonic aircraft are increased drag, meaning increased fuel consumption, and that famous “sonic boom”, a loud gunshot-like noise that disturbed anyone unfortunate to be under the flight path.

The blast, which occurs when the plane breaks the sound barrier, is why Concorde was limited to routes over the ocean. You could travel from London or Paris to New York at high speeds, but there was no onward connection to Los Angeles. And several other countries were forced to ban the plane from its airports or even airspace, for the disturbance it caused.

“Although the aircraft is moving faster than the speed of sound, it generates pressure waves that only move AT the speed of sound” explains Professor Karthik Duraisamy, from Stanford University, an expert in modeling this type fluid flow.

“The pressure waves start bunching up together, and create a so-called shockwave. If you’re standing on the ground and the plane flies above you, the wave passes over you. That’s the sonic boom.”

Big names in the aviation industry are trying to find solutions, including Boeing, Lockheed Martin, and Nasa. The space agency recently conducted wind tunnel tests of designs from both manufacturers that showed the showed the boom could be reduced to levels that are generally thought to be acceptable for routine overland flights. But an engineer at MIT, believes that a radical idea from the 1950s may hold the key to ‘boomless’, fuel-efficient craft.

Professor Qiqi Wang is part of a team that has shown that a bi-plane – essentially two, stacked wings – could bring huge improvements over the traditional delta-wing seen on Concorde. The idea was first proposed by German engineer Adolf Busemann, an influential aerospace designer who among other things first proposed the use of ceramic tiles to protect the Space Shuttle on reentry. According to theory, the Busemann bi-plane, when travelling at supersonic speeds, should produce less drag meaning it should use less fuel. Plus, the triangular wings can be “tuned” so that sonic boom is almost entirely eliminated.

“When we have two wings, if we place them in a carefully designed manner, the shockwaves from the two wings can cancel each other” says Prof.Wang.

However, the design has a major limitation for a plane – it lacks lift. The two wings create a narrow channel that limits the amount of air that can flow between them. When the plane accelerates through the sound barrier it becomes “choked” with air, causing an incredible amount of drag – much larger than a traditional Concorde-like design. This effectively means that a supersonic bi-plane works beautifully on paper, it could never reach supersonic speeds in the first place. Not only that, but the sonic-boom cancellation only works at a specific speed. If you are not at that exact speed, you don’t get the desired effect.

Shape shifters

To address these problems Wang turned to computer modeling to come up with an optimum wing shape for different speeds. The researchers then crunched through the 700 different shapes to produce an optimal configuration that would work at all speeds. Amongst the design tweaks they came up with were a smoothed inner surface for each wing to help air flow. The overall result is a wing that could fly at supersonic speeds, with half the drag of Concorde; something that could significantly cut fuel use.

Whilst it sounds like Wang and his team have cracked the problem, there is still a long way to go. So far, Wang has only shown the bi-wing concept working in two dimensions. Scaling this up to a three-dimensional prototype is more of a challenge. And expanding wing design to plane design, and getting everything to work together will be harder still.

“We are experts in designing components, and we are experts in designing something for a specific condition” says Duraisamy, who was not involved in the MIT work. In a supersonic aircraft though, nothing is constant. The conditions at take-off and landing are very different to the conditions at cruising speed. The plane encounters a whole range of possibilities, from different temperatures to different air densities.

“When you think about a supersonic aircraft it has to take-off at zero velocity, and has to reach a supersonic velocity and keep flying there,” says Duraisamy. “It also operates at zero altitude to extremely high altitude.”

But a Japanese group at Tohoku University may hold the key. The group has also been working on a Busemann bi-plane called Misora (Mitigated Sonic Boom Research Airplane and the Japanese for “beautiful sky”). However, unlike the MIT project that aims to design one wing for all uses, the Japanese project has proposed movable control surfaces so that the wings could change shape at different speeds. And if that sounds far-fetched, consider Concorde’s “drooping nose” that could be raised and lowered at different stages of flight. Of course to shape and sculpt a wing will take much more sophisticated technology and materials, but these shape-shifters could hold the key to next-generation supersonic air travel.

“I think that’s very likely” says Wang.

However if you are holding off booking that dream transatlantic trip in the hope of the shorter flight time in the near future, you may have a long wait. Duraisamy believes it will be “15 to 20 years” before anything like Concorde is seen in the skies again. And even then, it probably won’t get around all of the problems Concorde encountered.

“Maybe a supersonic business jet will come first,” he says, “because people are willing to pay the money.”

SOURCE:::::INPUT FROM ONE OF MY CONTACTS….truly amazing experience …a different and pleasant one …under a difficult circumstance…..It is once again proving that there are Good and Godly people everywhere in this world….worth sharing this story from a flight attendant of Delta Flight 15…..

Natarajan

Here is an amazing story from a flight attendant on Delta Flight 15, written following 9-11:

“On the morning of Tuesday, September 11, we were about 5 hours out of Frankfurt, flying over the North Atlantic. All of a sudden the curtains parted and I was told to go to the cockpit, immediately, to see the captain.
As soon as I got there I noticed that the crew had that “All Business” look on the
ir faces. The captain handed me a printed message. It was from Delta’s main office in Atlanta and simply read, “All airways over the Continental United States are closed to commercial air traffic. Land ASAP at the nearest airport. Advise your destination.”

“No one said a word about what this could mean. We knew it was a serious situation and we needed to find terra firma quickly. The captain determined that the nearest airport was 400 miles behind us in Gander, New Foundland.
He requested approval for a route change from the Canadian traffic controller and approval was granted immediately–no questions asked. We found out later, of course, why there was no hesitation in approving our request.

“While the flight crew prepared the airplane for landing, another message
arrived from Atlanta telling us about some terrorist activity in the New York area. A few minutes later word came in about the hijackings.
“We decided to LIE to the passengers while we were still in the air. We told them the plane had a simple instrument problem and that we needed to land at the nearest airport in Gander, New Foundland to have it checked out.

“We promised to give more information after landing in Gander. There was much grumbling among the passengers, but that’s nothing new! Forty minutes later, we landed in Gander. Local time at Gander was 12:30 PM! …. that’s 11:00 AM EST.

“There were already about 20 other airplanes on the ground from all over the world that had taken this detour on their way to the U.S. After we parked on the ramp, the captain made the following announcement: “Ladies and gentlemen, you must be wondering if all these airplanes around us have the same instrument problem as we have. The reality is that we are here for another reason.” Then he went on to explain the little bit we knew about the situation in the U.S. There were loud gasps and stares of disbelief. The captain informed passengers that Ground control in Gander told us to stay put.

“The Canadian Government was in charge of our situation and no one was allowed to get off the aircraft. No one on the ground was allowed to come near any of the air crafts. Only airport police would come around periodically, look us over and go on to the next airplane. In the next hour or so more planes landed and Gander ended up with 53 airplanes from all over the world, 27 of which were U.S. commercial jets.

“Meanwhile, bits of news started to come in over the aircraft radio and for the first time we learned that airplanes were flown into the World Trade Center in New York and into the Pentagon in DC. People were trying to use their cell phones, but were unable to connect due to a different cell system in Canada. Some did get through, but were only able to get to the Canadian operator who would tell them that the lines to the U.S. were either blocked or jammed.

“Sometime in the evening the news filtered to us that the World Trade Center buildings had collapsed and that a fourth hijacking had resulted in a crash. By now the passengers were emotionally and physically exhausted, not to mention frightened, but everyone stayed amazingly calm. We had only to look out the window at the 52 other stranded aircraft to realize that we were not the only ones in this predicament.

“We had been told earlier that they would be allowing people off the planes one plane at a time. At 6 PM, Gander airport told us that our turn to deplane would be 11 am the next morning. Passengers were not happy, but they simply resigned themselves to this news without much noise and started to prepare themselves to spend the night on the airplane.

“Gander had promised us medical attention, if needed, water, and lavatory servicing. And they were true to their word. Fortunately we had no medical situations to worry about. We did have a young lady who was 33 weeks into her pregnancy. We took REALLY good care of her. The night passed without incident despite the uncomfortable sleeping arrangements.

“About 10:30 on the morning of the 12th a convoy of school buses showed up. We got off the plane and were taken to the terminal where we went through Immigration and Customs and then had to register with the Red Cross.

“After that we (the crew) were separated from the passengers and were taken in vans to a small hotel. We had no idea where our passengers were going. We learned from the Red Cross that the town of Gander has a population of 10,400 people and they had about 10,500 passengers to take care of from all the airplanes that were forced into Gander! We were told to just relax at
the hotel and we would be contacted when the U.S. airports opened again, but not to expect that call for a while.

“We found out the total scope of the terror back home only after getting to our hotel and turning on the TV, 24 hours after it all started.

“Meanwhile, we had lots of time on our hands and found that the people of Gander were extremely friendly. They started calling us the “plane people.”
We enjoyed their hospitality, explored the town of Gander and ended up having a pretty good time.
“Two days later, we got that call and were taken back to the Gander airport.
Back on the plane, we were reunited with the passengers and found out what they had been doing for the past two days. What we found out was incredible.

“Gander and all the surrounding communities (within about a 75 Kilometer radius) had closed all high schools, meeting halls, lodges, and any other large gathering places. They converted all these facilities to mass lodging areas for all the stranded travelers. Some had cots set up,
some had mats with sleeping bags and pillows set up.

“ALL the high school students were required to volunteer their time to take care of the “guests.” Our 218 passengers ended up in a town called Lewisporte, about 45 kilometers from Gander where they were put up in a high
school. If any women wanted to be in a women-only facility, that was arranged. Families were kept together. All the elderly passengers were taken to private homes.

“Remember that young pregnant lady? She was put up in a private home right across the street from a 24-hour Urgent Care facility. There was a dentist on call and both male and female nurses remained with the crowd for the duration.

“Phone calls and e-mails to the U.S. and around the world were available to everyone once a day. During the day, passengers were offered “Excursion” trips. Some people went on boat cruises of the lakes and harbors. Some went for hikes in the local forests. Local bakeries stayed open to make fresh bread for the guests. Food was prepared by all the residents and brought to the schools People were driven to restaurants of their choice and offered wonderful meals. Everyone was given tokens for local laundry mats to wash their clothes, since luggage was still on the aircraft. In other words, every single need was met for those stranded travelers.

“Passengers were crying while telling us these stories. Finally, when they were told that U.S. airports had reopened, they were delivered to the airport right on time and without a single passenger missing or late. The local Red Cross had all the information about the whereabouts of each and every passenger and knew which plane they needed to be on and when
all the planes were leaving. They coordinated everything beautifully. It was absolutely incredible.

“When passengers came on board, it was like they had been on a cruise. Everyone knew each other by name. They were swapping stories of their stay, impressing each other with who had the better time. Our flight back to Atlanta looked li ke a chartered party flight. The crew just stayed out of their way. It was mind-boggling. Passengers had totally bonded and were calling each other by their first names, exchanging phone numbers, addresses, and email addresses.

“And then a very unusual thing happened. One of our passengers approached me and asked
if he could make an announcement over the PA system. We never, ever allow that. But this time was different. I said “of course” and handed him the mike. He picked up the PA and reminded everyone about what they had just gone through in the last few days. He reminded them of the hospitality they
had received at the hands of total strangers. He continued by saying that he would like to do something in return for the good folks of Lewisporte.

“He said he was going to set up a Trust Fund under the name of DELTA 15 (our flight number). The purpose of the trust fund is to provide college scholarships for the high school students of Lewisporte. He asked for donations of any amount from his fellow travelers. When the paper with donations got back to us with the amounts, names, phone numbers and addresses, the total was for more than $14,000!

“The gentleman, a MD from Virginia, promised to match the donations and to start the
administrative work on the scholarship. He also said that he would forward this proposal to Delta Corporate and ask them to donate as well. As I write this account, the trust fund is at more than $1.5 million and has assisted
134 students in college education.

“I just wanted to share this story because we need good stories right now. It gives me a little bit of hope to know that some people in a far away place were kind to some strangers who literally dropped in on them. It reminds me how much good there is in the world.”

“In spite of all the rotten things we see going on in today’s world this story confirms that there are still a lot of good and Godly people in the world and when things get bad, they will come forward.

SOURCE::::: “BRISBANE TIMES”….a funny and strange incident….but who was really sleeping !!!!—the pax or the airlines !!!

Natarajan.

Sleepy passenger goes on 18-hour round trip after missing stop

A Frenchwoman endured an 18-hour journey from the Pakistani city of Lahore to Paris and back again after sleeping through her plane’s stop in the French capital, officials said on Wednesday.

Pakistan International Airlines (PIA) are investigating how ground crew failed to notice the woman during the plane’s two-hour stopover at Charles de Gaulle Airport in Paris.

The woman, named as Patrice Christine Ahmed, who is married to a Pakistani, left Lahore at noon on Tuesday to fly to Paris via Milan, but did not wake up to get off the plane, airline spokesman Sultan Hasan said.

The woman did not mention her mistake to cabin crew and the matter only came to light when she was stopped by immigration officials on arrival back in Lahore on Wednesday morning – after a 12,000-kilometre round trip.

Hasan said PIA were investigating the incident and the French subcontractor responsible for passenger handling in Paris.

“We have put questions to this French firm also about the incident but it is also the responsibility of the passenger to disembark at the destination,” he said.

“It is a passenger’s responsibility to check about the destination and disembark when the plane arrives at the particular airport.”

PIA later arranged to send the woman back to Paris with another airline because none of its own flights were available, but said that the party responsible for the negligence will pay for the extra ticket.

“It depends who is at fault. If it is a mistake by the local firm, they will pay and if the woman herself is responsible than she will have to bear the cost,” Hasan said.