Many would have seen the viral email showing Boeing’s 1000-passenger “new” 797 (see photo) and of course it is figment of some creative artist’s imagination – or is it?

In fact it’s not so funny and the idea has been around since 1910 when famous German aircraft design Hugo Junker patented a wing-only air transport concept.

This evolved in 1931 into the Junkers G38 34-seater airliner which featured a large thick wing providing accommodation for passengers (see photo).

The plane actually accommodated passengers in the nose, the short fuselage and the wing.

Through the 1930s and 1940s US, German and Russian designers studied the flying wing for a variety of roles with the promise of huge fuel savings and thus greater range.

In 1946 Northrop flew the YB-35 flying wing bomber (see photo) and in 1947 the jet powered YB-49 (see photo).

Movie buffs may recall that it was the YB-49 that delivered an attack on the alien machines in the original War of the Worlds.

At the time Northrop touted the passenger appeal of the YB-49 and produced a fim touting its virtues (see video below).

Later Northrop would build the B2 Spirit stealth bomber.  

Studies into the passenger potential of the flying wing continue and Boeing has indeed conducted both passenger trials in mockups and also built and flown scale models.

However one of the problems is passenger acceptance of what would be a picture theater styled cabin with up to 15 to 20 across the width with four or more aisles.

Thus some passengers would be seated well away from the centre of the aircraft’s axis and thus subject to significant movement up and down in turns with motion sickness implications.

Offsetting this are the significant benefits from the fuel economy of the flying wing which some estimate would burn up to 40 per cent less fuel than conventional aircraft.

Investigators from the United Kingdom’s Air Accidents Investigation Branch have ruled out the 787’s battery as the source of the fire that damaged an Ethiopian 787 at Heathrow Airport on Friday.

Attention is now focused on the plane’s galley and questions are being raised as to whether a galley oven or coffee machine was left on or if cleaners and maintenance staff may have left a smoldering cigarette on board.

The 787, while powered down, was plugged into a ground power unit but it is unclear if the power was switched on.

Paul Hayes, director of air safety at Ascend, a British aviation consulting firm told the Wall Street Journal that one plane is lost on the ground to an electrical fire every five years.

Mr. Hayes said that several incidents were suspected to have started after a cleaner or ground worker furtively smoked on a parked plane and then failed to fully extinguish the cigarette.

In a statement Boeing said: “We’re aware of the 787 event at Heathrow Airport and have Boeing personnel there. We’re working to fully understand and address this.”

Boeing has delivered 66 787s and has orders for 930 planes.

The 787 is crammed with innovations including more electric systems rather than the traditional pneumatic systems that do not rely on bleed air from the engines.

The 787 has in all six electrical power generators and these provide power to the plane’s electrical systems in flight, including the flight deck displays, flight controls and in-flight entertainment. The system is more efficient because it reduces the drag on the engines.

However, New York based Bernstein Research, one of the industry’s foremost analysts, says that the fire damage appears to be near the vertical stabilizer, on the left side of the top of the 787 and as such should have very little connection to electrical systems.

While it is unclear what the cause of the fire is Bernstein says that it believes that there is no connection between the fire and the battery issues of the past.

“Because it appears that the 787 fire is not related to the battery, we believe it is likely that this is a one-off problem that certainly must be addressed, but does not pose a risk to the overall program,” said Bernstein.

Investigators from the United Kingdom’s Air Accidents Investigation Branch have ruled out the 787’s battery as the source of the fire that damaged an Ethiopian 787 at Heathrow Airport on Friday.

Attention is now focused on the plane’s galley and questions are being raised as to whether a galley oven or coffee machine was left on or if cleaners and maintenance staff may have left a smoldering cigarette on board.

The 787, while powered down, was plugged into a ground power unit but it is unclear if the power was switched on.

The AAIB said that “at approximately 1550 hrs UTC on 12 July 2013 a Boeing 787-8 of Ethiopian Airlines, registration ET-AOP, suffered an event at London Heathrow whilst the aircraft was parked on stand, with no persons on board.”

The investigation team which includes representatives from all interested parties has initiated the technical investigation into the event.

The 787 is currently located in a hangar at London Heathrow.

The AAIB reports that “there has been extensive heat damage in the upper portion of the rear fuselage, a complex part of the aircraft, and the initial investigation is likely to take several days. However, it is clear that this heat damage is remote from the area in which the aircraft main and APU (Auxiliary Power Unit) batteries are located.”

Paul Hayes, director of air safety at Ascend, a British aviation consulting firm told the Wall Street Journal that one plane is lost on the ground to an electrical fire every five years.

Mr. Hayes said that several incidents were suspected to have started after a cleaner or ground worker furtively smoked on a parked plane and then failed to fully extinguish the cigarette.

In a statement Boeing said: “We’re aware of the 787 event at Heathrow Airport and have Boeing personnel there. We’re working to fully understand and address this.”

Boeing has delivered 66 787s and has orders for 930 planes.

The 787 is crammed with innovations including more electric systems rather than the traditional pneumatic systems that do not rely on bleed air from the engines.

The 787 has in all six electrical power generators and these provide power to the plane’s electrical systems in flight, including the flight deck displays, flight controls and in-flight entertainment. The system is more efficient because it reduces the drag on the engines.

However, New York based Bernstein Research, one of the industry’s foremost analysts, says that the fire damage appears to be near the vertical stabilizer, on the left side of the top of the 787 and as such should have very little connection to electrical systems.

While it is unclear what the cause of the fire is Bernstein says that it believes that there is no connection between the fire and the battery issues of the past.

“Because it appears that the 787 fire is not related to the battery, we believe it is likely that this is a one-off problem that certainly must be addressed, but does not pose a risk to the overall program,” said Bernstein

The US crash investigator the National Transportation Safety Board has given the Asiana Boeing 777-200ER that crashed on Saturday July 6^th at San Francisco International Airport, killing three and injuring over 100, a clean bill of health noting all systems including auto pilot, auto throttle and flight director were working perfectly.

According to NTSB Chairman Deborah Hersman investigators found “no anomalous behavior.”

The NTSB also noted that the pilots were having trouble lining up for the landing on runway 28L. The airport’s Instrument Landing System, which gives an electronic guide to pilots, was not available but the visual Precision Approach Path Indicator was.

The pilots were instructor check captain, Lee Jung Min (49) who was assisting captain Lee Kang Kook, (46) who was being endorsed on the 777. Both captains were experienced. A third pilot – a co-pilot – was sitting in the observer seat.

According to the NTSB the 777’s speed decayed from a target speed of 137knots (253km/hour) to 103 knots (191km/hr) which went unnoticed till nine seconds before impact.

“There is no mention of speed until about nine seconds before impact,” said Mrs Hersman.

Captain Lee Jung Min earlier told the NTSB that he assumed that the auto throttle –similar to cruise control in a car – was maintaining the required speed of 137knots.

However Mrs Hersman told media that “they [the pilots] are required to monitor their instruments during landing – particularly the speed.”

Pilots work as team with one flying the plane the other supporting with read backs on critical data, setting flaps, lowering undercarriage and reading checklists.

The instructor captain Lee Jung Min also told investigators that he saw three red and one light on the PAPI lights indicating too low and called for more power. Then he told investigators he could see four red lights and notice the airspeed was in the hatched area on the display– indicating too slow.

Mrs Hersman said that two different members of the cockpit crew – the instructor captain and the observer co-pilot – made separate calls to abort the landing, three seconds and 1.5 seconds before the crash. Power was applied but it was too late.

The pilot flying also reported being blinded by a flash of light on approach however the source of the light and its role in the crash are not known the NTSB said.

Mrs Hersman also clarified the evacuation and noted that the cabin crew had sought guidance from the pilots but they initially, unaware of the fire, told flight attendants not to initiate evacuation procedures.

Only when the flight attendants told them of the fire was the order given to evacuate.

“We don’t know what the pilots were thinking, though I can tell you in previous accidents there have been crews that don’t evacuate, they wait for other vehicles to come to be able to get the passengers out safely,” said Mrs Hersman.

However once the call was made the passengers were out within 90 seconds.

The US crash investigator has laid responsibility of the slow speed of the Asiana 777 that crashed at San Francisco International Airport on the weekend, killing two, with the pilots.

Yesterday one of the Asiana pilots, responsible for monitoring the instruments, said he assumed that the auto throttle was maintaining the minimum speed required for safe flight.

However, the US National Transportation Safety Board Chairman Deborah Hersman told a media conference that the pilots are required to also monitor their instruments during landing.

“Let me be very clear the crew is required to maintain a safe aircraft. That means they need to monitor and we have a flying pilot and we have two other pilots who have a monitoring function,” said Mrs Hersman.

“And one of the critical things that needs to be monitored on an approach to landing is the speed.”

The instructor check captain, Lee Jung Min (49) who was assisting captain Lee Kang Kook, 46 being endorsed on the 777, told investigators that he assumed that the auto throttle – similar to cruise control in a car – was maintaining the required speed of 137knots (253km/hr).

However, while the auto throttles were engaged, it is not clear as yet what mode they were in.

The 777’s speed sank to just 103 knots (190km/hr) just before it hit the sea wall.

The two pilots are supposed to work as a team with one flying the plane the other supporting with read backs on critical data, setting flaps and lowering undercarriage and reading checklists.

Instructor captain Lee Jung Min also told investigators that he saw three red and one light on the Precision Approach Path Indicator (PAPI) indicating the plane was too low and called for more power.

Then he told investigators he could see four red lights and noticed the airspeed was in the hatched area on the display – indicating too slow.

Mrs Hersman also confirmed that a third pilot – a first officer – with over 4,500 hours of flying experience, was the observer pilot in the cockpit.

Interestingly, and in a sign of what was to come, he said he could not see the runway or PAPI lights because the 777’s nose was too high.

In a normal approach an observer in the cockpit can see both the runway and the PAPI lights if the attitude of the 777 is correct.

A pilot from a plane waiting for take-off also noticed the very high angle of the 777’s nose, which would account for the rapid speed loss, if – as was the case – the engines were at idle.

Automation has had an extraordinarily positive impact on improving aviation safety but it can be – and has been – a trap for the unwary.

A number of years ago one crew of a 747 entered the heading they wanted to fly into the auto throttle, instead of the speed and the aircraft almost stalled after take-off.

Scant seconds before Asiana Flight 214’s tail struck the seawall at San Francisco International Airport the crew got a visceral warning of what might happen unless they added life-giving speed: the “stickshaker” started ominously vibrating in the pilot’s hands, emitting an impossible-to-ignore rattling sound, the sound indicating an incipient stall if the pilot didn’t take immediate corrective action.

So, just what is a stall? What are the aerodynamic principles behind the lift-killing phenomenon?

Wings work wondrously, and the end product is something called lift — the most elemental of forces, the phenomenon upon which rests all aeronautical laws and prophesies.

Early aviators reasoned they could loft a machine into the heavens by curving the top of its wing. Air passing over the arched upper surface had to travel farther, and thus faster, than the air passing beneath. Fast air “weighs” less than slow air. That’s because its molecules are spread out. The wing is literally sucked up into lower pressure above, while being nudged up by the higher pressure below. That’s the essence of lift, something spelled out nicely in a law of physics called Bernoulli’s Principle. 

Lift is lovely. But it’s perpetually at war with drag. Lift gets us off the ground. Drag seeks to tether us to it. Drag is a combination of forces: friction, gravity and downward air pressure. When it dominates, bad things can happen. At worst, airplanes can fall from the sky.

Lift increases with how sharply the airfoil (another term for the wing) is angled into the air. But the principle works only just so far. Beyond an angle of about15 degrees, the airflow over the upper surface of the airfoil separates from the wing itself. What was a smooth, lift-producing flow becomes a turbulent, roiling cauldron and the wing “stalls.” The upwards suction disappears!

To restore lift, you can push the nose of the airplane over and gain airspeed. Asiana 214 was too low at the time to do this. All the pilot could do is try to restore lift-giving speed is to push the power levers (a.k.a. “throttles”) up. But the engines take a few seconds to spool up to full power and time had tragically disappeared – along with altitude.

To prevent a stall from happening in the first place, to allow airplanes to climb more steeply, and fly at slower speeds, designers begat flaps on the trailing edge (the rear), and slats on the leading edge (the front) of the wing. Both extend the curvature of the wing. But even that has its limits. Keeping an airplane aloft requires a requisite amount of speed. Absent that, an aircraft can sink too fast of simply stall out. It appears the 777 did the former. Just before impact the Triple-Seven was traveling far below its targeted approach speed. According to the crash investigator the US NTSB the Asiana 777 was travelling 34 knots or 39m/hr (62km/hr) below its target speed at its slowest point just before impact. At impact it had gained just 3 knots.

Back to the physics of it all for a moment: slats are critical at takeoff and landing, when an aircraft has to gain altitude at a steep angle while flying relatively slowly, or descend – nose canted slightly up – and maintain lift at the same time.

The MD-80 was one of the first aircraft fitted with an automatic slat extension feature that gives pilots a greater margin for error. Ralph Brumbry, once a designer on the MD-80 project, said, “When slats are in the mid-extension position and, for any reason, you should slow down or approach stall, the change is sensed [by computers] and the slats open automatically to their full extension.” When the MD-80 gasps for a smooth gulp of lift it’s there – instantly and automatically.

On takeoff, flaps are normally pitched between 10 and 20 degrees below the plane of the wing. On landing – when you want to go slower (but not too slow) – it can vary between 30 and 45 degrees. 

Together, slats and flaps sculpt the air, augmenting the gravity-defying lift bequeathed by the wing itself. But even they need a minimum amount of airspeed to make the magic work. 

The speed of the Asiana 777, just seconds before landing, has become the major focus of investigators probing Saturday’s crash at San Francisco airport which killed two and injured scores of other passengers.

National Transportation Safety Board (NTSB) chairman Deborah Hersman told reporters at a news conference Sunday that crew called out to abort the landing about 1.5 seconds before impact.

Hersman said the 777 was travelling at a speed well below the target landing speed of 137 knots, or 157 mph or 253km/hr.
“We’re not talking about a few knots,” said Hersman.

The NTSB also said that the 777’s stick shaker — a piece of safety equipment that shakes the control column and warns pilots of an impending stall — went off seconds before the crash.

At about 6 seconds before impact there was a call for “power” and the engines responded and at 1.5 seconds before the crash, there was a call to abort the landing, said Hersman.

For a minimum speed pilots would typically add about 5 to 6 knots and program this into the auto thrust system which would maintain that speed.

There was no indication on the CVR or ATC tapes of any discussions between the pilots and the air traffic controllers that there were problems with the 777.

The NTSB is looking at the impact of the shutdown of the airport’s instrument landing system which provides two guides – lateral and vertical – to the pilots.

Hersman said that the pilots were sent a notice warning (NOTAM) that the ILS wasn’t available. But Hersman said that “there were many other navigation tools available to help pilots land.”

One of the survivors of the crash Elliott Stone told CNN that as the plane came in to land, it appeared the pilot “sped up, like the pilot knew he was short.”

On impact the 777’s tail assembly ripped away, sending the plane into a spin ripping off the undercarriage and engines.
Eye witnesses say that after a loud bang there was a brief but large fireball from underneath the plane, which may have been one of the engines ripping off its mounting.

The 777 came to rest between the two parallel runways with its rear pressure bulkhead, near where the flight attendants were seated, split open.

Miraculously the 777’s wings, which hold all the fuel, stayed intact, almost certainly preventing a catastrophic explosion and possibly hundreds of deaths.

However a fire broke out on the right side of the 777, probably started by fuel spilt from the engine that came to rest against the plane’s fuselage.

The 777 was operating Flt 214 from Shanghai to San Francisco via Seoul with 307 passengers and crew and it struck the sea wall 100m short of the runway threshold at 11.36am local time.

Among those on board were 77 Koreans, 141 Chinese, 61 US citizens, and one Japanese national, Asiana said in a statement
The San Francisco Fire Department took 181 to hospitals in the immediate area.

San Francisco Mayor Ed Lee told Bloomberg it was very lucky there were so many survivors.

“This could have been much worse,” Mr Lee said.

San Francisco General Hospital and Trauma Centre admitted 52 patients, with five in critical condition, according to spokeswoman, Rachael Kagan.

“Some of them are in shock. Some are very tearful, some look stunned,” Chris Barton, chief of the hospital’s emergency department, told Bloomberg yesterday.

“Overall I think it’s amazing how most of the patients are coping.”

However Mr Barton said that there were a number of patients with spine injuries.

“I’m guessing it’s from the force of the plane going down on the long axis of the spine.”

Weather has all but been ruled out as a factor in the crash.

Arrivals at San Francisco airport were being conducted under visual flight rules and typically plane would not have been using auto land capability.

Both San Francisco airport and the Boeing 777 are equipped for the highest auto land capability.

Immediately after the crash the airport was closed to all traffic with up to 300 flights diverted or cancelled.

Later two of the airport’s four runways were reopened.

Asiana is South Korea’s second-largest airline after Korean Air.

The airline has a fleet of 78 planes.

There are over 1000 Boeing 777s in service and the aircraft has a fatality free crash record up till this accident.

The last hull loss was to a British Airways 777 on January 17 2008 when fuel icing caused a restriction in the fuel lines reducing power to the engines.

The British Airways 777 landed 300 mtrs short of the runway and all 152 passengers and crew walked away.

An Egypt Air 777 suffered an electrical fire on the ground in 2011 after a fault in the cockpit and was written off.

The airline industry is enjoying its safest year ever so far with only 52 fatalities from 11 accidents according to www.aviation-safety.net The 10-year average is 325 fatalities from 16 accidents.

According to IATA for 2012 the industry Western-built jet hull loss rate was 0.20 per million sectors flown, which is a 77% improvement in the accident rate over the last 10 years.

Incredibly IATA member airline accident rate was 0.00.

According to IATA the region with the worst crash rate for western built aircraft is Africa with 3.71 crashes per million sectors.