17 JUL 2009 _______________________________________ *Southwest 737 Investigation May Look Into Previous Maintenance Violation *NTSB: Southwest Airlines jet with hole had no corrosion, prior mechanical damage *Pilots' group criticizes EU over fatigue delay *Moscow CRJ crash inquiry blames wing icing again *EASA orders A310 checks after in-flight wing-fence losses *************************************** Southwest 737 Investigation May Look Into Previous Maintenance Violations Aircraft Section That Failed May Not Have Been Covered By 2004 AD The NTSB Investigation of a Southwest Airlines Boeing 737-300 which experienced a cabin depressurization earlier this week may hinge on an old maintenance violation the airline thought it had covered with a design improvement. A 2004 AD (2004-18-06) "...applicable to certain Boeing Model 737-200, -200C, -300, -400, and -500 series airplanes, requires repetitive inspections to find fatigue cracking of certain upper and lower skin panels of the fuselage, and follow-on and corrective actions, if necessary. This amendment also includes terminating action for the repetitive inspections of certain modified or repaired areas only. This action is necessary to find and fix fatigue cracking of the skin panels, which could result in sudden fracture and failure of the skin panels of the fuselage, and consequent rapid decompression of the airplane. This action is intended to address the identified unsafe condition." There are then several pages of clarifications. "It looks like that would apply," Peter Knudson, an NTSB spokesman, told the Dallas Morning News Wednesday. "We are going to look at the maintenance records and the maintenance practices, and we are going to want to know if all of these [regulations] were followed." Southwest was fined $7.5 million in 2008 when it was discovered it was continuing to fly 46 aircraft that were due for inspection for structural damage. 6 of those were found to have stress fatigue cracks. The case was settled earlier this year, negotiated down from an original fine of $10.2 million. FAA officials told the paper that a service bulletin issued by Boeing recommends that inspections should focus on areas where two major skin panels join, but did not specify inspection of the long panels at the top of the aircraft. The paper also reports that NTSB may investigate whether the aircraft was damaged during re-painting. A Southwest spokeswoman said the most recent inspection of the aircraft had revealed no problems. She declined to comment on the re-painting issue, citing an ongoing NTSB investigation into an incident that took place with another airline in 2003. FMI: www.ntsb.gov, www.faa.gov aero-news.net *************** NTSB: Southwest Airlines jet with hole had no corrosion, prior mechanical damage The National Transportation Safety Board said Thursday that the football-size hole that opened up in the top of a Southwest Airlines Co. Boeing 737 on Sunday night bore no signs of "significant corrosion or obvious pre-existing mechanical damage." The report, the NTSB's first on the incident, left open the possibility that some sort of fatigue of the aircraft's aluminum skin near where the aircraft tail attaches to the fuselage could have created the hole. The 15-year-old Boeing 737-300 was flying from Nashville to Baltimore at 34,000 feet when the incident occurred; the plane landed without injury to 126 passengers or to crew members. Investigators may look at whether Southwest complied with federal regulations that govern inspections of aging aircraft. The NTSB said the hole measured 17 by 8 inches. Its investigators will conduct a much deeper metallurgical analysis to see whether some microscopic problem with the aluminum might have created the tear as a result of the expansions and contractions the fuselage endures on every flight. Some experts think work done on the plane, such as heavy maintenance completed in January or repainting, might inadvertently have damaged the skin, but not in a visible way. As the plane continued to fly, unseen cracks could, in theory, have resulted in the hole. But experts caution that it's too early to conclude anything. http://www.dallasnews.com/sharedcontent/dws/bus/stories/DN-swjethole_17bus.A RT.State.Edition1.3cfe297.html ***************** Pilots' group criticizes EU over fatigue delay BRUSSELS (AFP) — A European pilots association criticized the EU on Friday, saying the bloc is endangering air safety by failing to act on the recommendations of experts who say cuts in flying hours are needed to curb pilot fatigue. The European Cockpit Association, which groups pilots unions with 38,000 members, praised the action taken by the U.S. Federal Aviation Administration in the wake of the Colgan Air crash in February which killed 50 people. The FAA said Monday it will propose setting new limits on how many hours airline pilots can fly in an effort to prevent pilot fatigue from endangering flight safety. "Does Europe also need a fatal accident before actions are taken over here?" said Philip von Schoppenthau, secretary-general of the European Cockpit Association. Von Schoppenthau said the EU's European Aviation Safety Agency has stalled on implementing similar limits proposed last fall by a panel of aviation experts and scientists. An agency spokesman did not immediately return calls seeking comment Friday. Last year, the panel came to the conclusion that EU rules are insufficient to adequately protect against the flight safety risks posed by pilot fatigue. It found that the allowed maximum daily flight duty period of 13-14 hours "exceeds reasonable limits." Among other recommendations, the panel called for the current maximum of 11:45 hours of night duty be cut to 10 hours because of the high risk of fatigue at night. But action on the proposals has been blocked since January, after an industry association challenged the panel's findings. The Association of European Airlines, a grouping of the continent's flag carriers, charter operators and low-cost carriers, has lobbied against the new rules, arguing the study was scientifically flawed and that experience has shown that current limits are adequate. Analysts say the new limitations would significantly boost operational costs at a time when revenues are falling because of the economic downturn. "The American example shows you can move things forward if there's political will," von Schoppenthau said in an interview. "But we see that on the European side political will is still absent." ****************** Moscow CRJ crash inquiry blames wing icing again Russian investigators have again blamed icing for the crash of a corporate Bombardier CRJ regional jet during departure from Moscow Vnukovo two years ago. The US-registered CRJ100SE aircraft, operated by Nabban Investment, was heading to Berlin for servicing by Lufthansa Technik, but lost lift immediately after becoming airborne from runway 06. Its right wing contacted the runway surface and the aircraft overturned before catching fire. Snowy conditions and a crosswind had prevailed at the time, and the temperature was about minus 6°C. Russia's Interstate Aviation Committee (MAK) believes that, while the aircraft underwent de-icing before the 13 February 2007 flight, the timing and method of the procedure did not result in adequate protection. MAK also compared the take-off by the Vnukovo CRJ with 30 other previous departures by the same aircraft, and found that the parameters "different in all indices" from the average. The aircraft rotated early and the pitch rate on rotation, for example, was double the recommended 3° per second for cold-weather conditions. Analysis of the flight indicates that the loss of lift was asymmetric. The CRJ started rolling left as it took off, reaching a bank of 29°, then rolled to the right as the crew attempted to stabilise the aircraft. It reached a right bank of 81° before the wing-tip hit the runway. Despite the destruction of the jet, all three occupants survived. MAK has already attributed to icing the similar loss of a Belavia CRJ100 at Yerevan, almost exactly one year after the Vnukovo crash. In its final report into the Vnukovo accident, it also highlights four other incidents between 2002 and 2007 which have occurred under similar circumstances. Source: Air Transport Intelligence news *************** EASA orders A310 checks after in-flight wing-fence losses European safety regulators have ordered Airbus A310 operators to check the type after at least three carriers suffered in-flight loss of wing fences. All three reported wing-fence detachment from A310-300 aircraft, says the European Aviation Safety Agency (EASA). Inspection of other examples of the twin-jet has uncovered cracked internal ribs within the wing-tip structure. Initial examination suggests these cracks are the result of fatigue and EASA says that, uncorrected, the condition could lead to further wing-fence losses, with possible injury to people on the ground. EASA has issued an airworthiness directive covering repetitive inspection on a number of A310-300 aircraft, but says it also applies to two specific A310-200s - currently listed in the fleets of FedEx and Air Bagan. Operators could alternatively replace both wing tips with a modified design in accordance with an Airbus service bulletin. Source: Air Transport Intelligence news *************** Curt Lewis, P.E., CSP CURT LEWIS & ASSOCIATES, LLC