The entire global fleet of Airbus A380 superjumbo jets are to be checked for cracks inside the wings.

The European Aviation Safety Agency (EASA) last month ordered “a detailed visual inspection”. The checks are to be extended to the entire fleet of 68 planes flying with seven different airlines, it was announced yesterday.

The EASA say they are working with Airbus on a “long-term fix” for the problem that should be ready by the summer. The decision to extend the order was made after the first set of results of inspections, but EASA say they don’t have details on how many cracks have been found in total. The checks are on the aircraft’s “wing rib feet” - the metal brackets that connect the wing’s ribs to its skin. (Graphic showing the location of the wing rib brackets in an A380 superjumbo, which are at the centre of concerns over cracking. Source: Airbus) 

The EASA’s original order came when Airbus said it had found new cracks on the brackets inside the wings of two superjumbos after inspections launched following a 2010 incident in which a Qantas A380’s engine disintegrated in flight. The agency gave airlines between four days and six weeks from January 24 to carry out checks on the initial batch of superjumbos, whose future customers include British Airways and Virgin Atlantic. Under the extended order, planes that have flown fewer than 1,300 takeoff and landing cycles will have to be checked before reaching that point, and planes that have flown more will have to be inspected within three weeks. 

Airbus said it has developed repair kits for the problem, which are currently being installed, and that the aircraft remained safe to fly. “These brackets are located on wing ribs which are not main load bearing structure, and, thus, the safe operation of the aircraft is not affected. “Nearly 4,000 such brackets are used on the A380 to join the wing-skin to the ribs. Only a handful of brackets per aircraft have been found to have been affected.” EADS said.

Still, EASA in its directive said that "this condition, if not detected and corrected, could potentially affect the structural integrity of the airplane."The airworthiness directive last month applied to the 20 planes that have flown the most. EASA spokesman Dominique Fouda said the updated directive extends the checks to the entire fleet of 68, currently flying with seven different airlines."In parallel, we are working with Airbus on a long-term fix that should be ready by the summer," He said the decision to extend the order was made "given the first results" of the inspections, but said he didn't have details on how many cracks have been found in total. EASA's original Jan. 20 order came after Airbus said it had found new cracks on the brackets inside the wings of two superjumbos after inspections launched following a 2010 incident in which a Qantas A380's engine disintegrated in flight. 

The agency gave airlines between four days and six weeks from Jan. 24 to carry out checks on the initial batch of planes. Earlier Wednesday, Australia's Qantas Airways said it was temporarily grounding one of its A380s after discovering dozens of hairline cracks in its wings. It said, however, that the cracks were of a different type from those that prompted EASA's Jan. 20 directive

Aviation Safety: evolution of airplane interiors

The accident fatality rate for jet airplanes has fallen dramatically during the last 50 years. This decrease is due in part to continuing efforts by airplane manufacturers and regulators to use information gained from accidents to develop safer, more survivable airplanes. 

A history of improving airplane interiors

Since the first passenger airplane was introduced in the 1930s, airplane manufacturers have worked to make airplanes safer for the passengers and crew who fly in them. For example, Boeing has worked continuously to enhance the safety of its products and to lead the industry to higher levels of safety through global collaboration by working together, regulators, operators, and manufacturers can maximize safety by sharing knowledge and targeting safety efforts to address areas with the most risk. Some recent events highlight the safety of today’s passenger jet airplane interiors during takeoff and landing accidents.

Boeing 247, 1933

In December 2008, an airplane crashed while taking off, ending up on fire in a 40 foot deep ravine several hundred yards from the runway. There were no fatalities among the 115 passengers and crew, even though the metal fuselage had been breached by fire. 

In December 2009, an airplane carrying 154 passengers and crew overran the runway during a landing in heavy rain and broke apart. There were no fatalities. accidents involving the current generation of commercial airplanes are rare but offer important insights into advancements in the safety and crashworthiness of airplane design. These advancements reflect decades of innovation and targeted efforts to improve survivability in an airplane accident, especially during takeoffs and landings. 

Boeing 707, 1958

in august 2010, an airplane crashed while attempting to land during poor weather, breaking into three pieces on impact. There were 125 survivors among the 127 passengers and crew aboard the flight. The industry’s work on airplane safety and survivability of airplane interiors emphasizes three areas: surviving impact, surviving a fire, and evacuation.

Surviving Impact

Survivability is greatly influenced by seat design. The greater the ability of airplane seats to remain in place and absorb energy during an impact, the greater the likelihood of passenger survival. in addition, the seat back is designed to protect passengers behind the seat from head injury. Seat design. in the 1930s, passenger airplane seats could withstand a static force six times the force of gravity (6g). For commercial jet airplanes beginning in the 1950s, the 6g requirement was raised to 9g. Today’s seats are required to withstand a 16g dynamic force. a 16g seat is tested in a manner that simulates the loads that could be expected in an impactsurvivable accident. 

Boeing 787, 2001

Two separate dynamic tests are conducted to simulate two different accident scenarios: one in which the forces are predominantly in the vertical downward direction and one in which the forces are predominantly in the longitudinal forward direction. The highest load factor is in the forward direction at a force of 16g. Head injury protection. Where head contact with seats or other structure can occur, boeing provides protection so that the head impact does not exceed the Head Injury Criterion (HIC) established by the u.S. Federal aviation administration (FAA). HIC measures the likelihood of head injury resulting from an impact. compliance with the Hic limit is demonstrated during a dynamic sled test that includes a 50 percent male size test dummy, the seat, and any airplane structure that could be impacted by the occupant’s head. 

Surviving a fire

Floor proximity lighting under dark conditions

In 1985, the FAA developed a new test standard for large surface area panels, such as ceilings, walls, overhead bins, and partitions. The standard required that all commercial airplanes produced after august 20, 1988, utilize panels that exhibit reduced heat and smoke emissions, delaying the onset of a flashover (i.e., the simultaneous or near simultaneous ignition of all flammable material in an enclosed area). interiors are updated and refurbished many times during the life of an airplane. This results in interiors that incorporate these enhancements even in older airplanes. in addition, airplanes manufactured on or after august 20, 1990, must comply with definitive standards of a maximum peak heat release rate of 65 kilowatts per square meter, a maximum total heat release of 65 kilowatt minutes per square meter, and specific optical smoke density of 200 (i.e., the OSu 65/65/200 fire safety standard defined by Ohio State university). extensive fire protection systems are also part of every Boeing passenger airplane. These systems include the use of fire protective materials, smoke detection and fire extinguishing systems, and insulation blankets designed to resist burn through from a fuel fire next to the bottom half of the fuselage. 

Evacuating the Airplane

Floor proximity lighting under smoky conditions

The FAA requires that an airplane can be evacuated of all passengers in 90 seconds. Boeing airplane interiors include a number of features to facilitate this process. These features include floor proximity lighting and escape slides. Floor proximity lighting. When passengers evacuate after a crash, buoyant hot smoke and gases can fill the cabin down to near floor level, obscuring overhead lighting. evacuation is improved through the use of lights, reflectors, or other devices to mark the emergency escape path along the floor. The Faa determined that floor lighting could improve the evacuation rate by 20 percent under certain conditions. as a result, the U.S. commercial fleet was retrofitted with floor proximity lighting by 1986, marking the completion of a two year compliance schedule. The 777 was the first Boeing airplane to include floor proximity lighting in production models.

Doing nothing is not an option – laser Interference Seminar conclusions 

Malicious use of powerful laser pointers to dazzle pilots and controllers is rising. Prompted by stakeholders, EUROCONTROL hosted a seminar on this issue at which participants called on the EU for stringent regulation on the abuse of lasers.

The United Kingdom had 30 instances in 2007 and there have been around 1,600 up until September 2011. EUROCONTROL’s Voluntary ATM Incident Reporting (EVAIR) had 8 reports in 2008 and 500 in 2010.

According to FAA data, there were 1,049 reports in 2010 but this year has already seen 1,503 laser interference incidents in the United States. A safety report that is about to be published notes that in 2009, there were 1,048 reported incidents in ECAC states and in 2010, there were 4,266(1).

Laser interference is growing and presents a global safety and security threat; it is not just an aviation issue.

Previous discussions centred on the legitimate uses of laser and the International Civil Aviation Organisation, ICAO, developed standards to regulate on this. However, laser interference tactics have changed and a harmonised, multidisciplinary and pro-active approach is needed to counter this threat.

Prompted by stakeholders, EUROCONTROL hosted a seminar on laser interference in aviation on 10 – 11 October.

Some 160 representatives from a variety of sectors in the aviation field, regulatory, law enforcement and research institutions attended. The seminar was organised together with the European Commission, ICAO, the European Cockpit Association, IFALPA, IATA and the Association of European Airlines.

Participants at the seminar agreed that timely and effective in-flight and post-flight procedures for dealing with interference are needed – as well as training in these procedures for both pilots and air traffic controllers.

Alerting processes to the authorities have to be defined and awareness campaigns run. Guidance material for decision-making is also required. It was also felt that advances in nanotechnology filters might prove helpful in the future.

At present, only a handful of European states have state regulations on laser interference and the seminar felt that judicial measures should be taken further. The seminar concluded by calling on the European Union to develop stringent regulation on the production, distribution, purchase, carriage and use of lasers.

(Source: EUROCONTROL)

Losing an Engine on Takeoff: Abort or Floor It?

There is a little more than a mile of pavement in front of the pilots;  the flight has been cleared for takeoff.  The Captain advances the power while the brakes are held.  Engine instruments checked, automatic control of the throttles engaged, and the brakes are released.

The computer pushes the engines to maximum takeoff power, and the aircraft begins its rapid acceleration down the runway.  With over half of the runway behind it, and accelerating through 140 MPH, an engine fails.  “Is there enough runway to stop?”  “Can the aircraft takeoff on the one remaining engine?”  “Will it clear the trees at the edge of the airport?”  The crew is faced with this daunting choice, and they react quickly.  It may seem like one has to consider all these factors, or even rely on gut instinct.  But in fact, the decision has already been made.

Engine failure on takeoff is a situation that all pilots both dread and train for. In small twin-engined aircraft, when an engine fails on the takeoff roll, the remaining engine is brought to idle, and the aircraft is stopped on the runway.  If the engine quits just after takeoff, the pilot may have enough runway available to still land safely.  There is a point, based on the judgment of the pilot, that sufficient runway is unavailable.  At this point, the landing gear is retracted, and the pilot would continue to climb out on the remaining engine.  Many of these principles apply to large turbojet aircraft, though the total picture is far more complex.

Per FAA regulations, an airliner must be able to either abort the takeoff and stop on the runway, or continue with the takeoff and climb out on the remaining engine.  There is a point, or rather a speed that defines this point in which the aircraft can safely either be stopped or continue with the takeoff.  This is commonly referred to as decision speed.

Decision speed, which pilots refer to as V1, is calculated for every takeoff.  Unlike the pilot of a small piston twin who must make a judgment call when the engine quits, the Captain of an airliner relies on the science, testing, and calculations from which the decision speed is derived.

Decision speed falls within a range of speeds; the highest of this range is based on the ability of the aircraft’s brakes, which is especially relevant on older intercontinental airliners.  Passing through 160 MPH, these aircraft simply have insufficient braking capability to stop.  If the Captain were to abort above this speed, the brakes would heat rapidly, melt, and around 60 MPH, simply cease to exist.  Off runway terrain and obstructions would eventually bring the heavy aircraft to a halt.

The lowest of this range is based on the minimum speed of which the aircraft is controllable with the failure of one engine.  When an engine fails, the remaining engine will make the aircraft turn in the direction of the failed engine.  This yaw is counteracted by the pilot’s application of the rudder, which directs the airflow over the tail, counteracting the yaw from the engine.  Whereas the force of the thrust from the engine remains relatively constant during the takeoff, the amount of force the rudder can generate is entirely dependant on the aircraft’s speed.  The higher the speed, the greater amount of airflow over the tail, and thus the greater the force generated by the rudder.  There is a speed at which the force of the rudder equals the force of the yawing from the engine.  Above this speed, the pilot is able to control the direction of the aircraft with the rudder.  Below this speed, the remaining engine will overpower the rudder and the aircraft will loose directional control.  This speed, denoted as Vmcg (minimum control ground), plus a small fudge factor, define the low end of the V1 range.  If the aircraft is going to continue the takeoff, it must be controllable, thus the requirement of V1 being higher than Vmcg.

The departure runway is the primary input for the calculation of V1.  Two basic criteria must be met; the aircraft must be able to abort the takeoff and stop on the remaining runway just prior to reaching V1, or continue the takeoff with the engine failure after having reached V1.  If the takeoff is continued, the aircraft must be able to rotate, clear the end of the runway by 35 feet, and climb steeply enough to clear any trees, buildings, and other obstacles.

Other factors that go into the calculations are: engine power, atmospheric conditions, runway conditions, and aircraft weight.  If the criteria of V1 cannot be met, it is not permissible for the aircraft to depart.  To remedy this, the Captain may choose another suitable runway.  If one is not available, the only remaining choice is reduce the aircraft weight, typically by bumping passengers.  Due to the short runway and steep climb required, Washington Reagan National and John Wayne Orange County airports are places where passengers are often left behind due to V1 considerations.

The decision on when to abort the takeoff or continue on one engine is made well prior to entering the runway.  Whether the aircraft slams on the brakes and stops at the end of the runway, or continues the takeoff and returns for landing, the passengers will be returning to the gate.  Safely.

(Source: NYCAviation)

ALPA Urges Release Of Pilot Fatigue Rule
Union Notes Safety Regs More Than Two Months Overdue

New regulations for minimum crew rest periods, based on science, were a personal crusade for FAA Administrator Randy Babbitt when he first took the job. They were demanded by Congress after the Colgan 3407 crash. And a panel of industry stakeholders got together and created them. But they've been sitting for months, bottled up in an administrative review process.

ALPA, the Air Line Pilots Association, International, joined more than 100 members of Congress Tuesday in calling on President Obama to ensure that US airline pilots are adequately rested to safely perform their jobs by directing the appropriate agencies to immediately issue standardized flight- and duty-time limits and minimum rest requirements for flight crews.

“Despite the two months that have passed since the deadline set by Congress, the new science-based pilot fatigue regulations remain stalled in bureaucratic review,” said Captain Lee Moak, ALPA’s president (pictured). “This delay is unconscionable, considering the risk that exists for U.S. troops, airline passengers, and cargo shippers who rely on safe air transportation.”

ALPA emphasizes that the FAA Aviation Rulemaking Committee addressing airline pilot flight- and duty-time limits included representatives from all types of flight operations–domestic, international, regional, and supplemental. Every segment of the industry had a voice in the process that created a recommended science-based regulation to provide one level of safety for all Part 121 operations.

“Given the historic collaboration and compelling science behind these new regulations, President Obama must safeguard air transportation by directing the swift release of a final standardized rule,” said Captain Moak. “With the safety of the traveling public at stake, it is simply impossible to justify anything less than immediate action.”

ALPA represents more than 53,000 pilots at 39 airlines in the United States and Canada.

(ALPA)