PICKLE FORKS CRACKS - On youth fleet of B737 NG - Severe vibration incident on a Boeing Model 737-800 series airplane

 

The aircraft, registered B-1791, was 6.8 years old and completed 8,986 flight cycles. It had not met the ‘pickle fork’ inspection threshold of 22,600 flight cycles.	A aeronave, registrada B-1791, tinha 6,8 anos e completou 8.986 ciclos de voo [decolagem/pouso]. Não havia atingido o limiar de inspeção do "garfo de picles" de 22.600 ciclos de voo.
“pickle forks are “designed to last more than 90,000 landings and takeoffs without cracking…and there could be dire results if the system fails”. A former Boeing engineer who asked to remain anonymous tells KOMO that the issue is especially concerning as it was found relatively early in the plane’s service:	"Garfos de picles” são projetados para durar mais de 90.000 pousos e decolagens sem quebrar... e pode haver resultados terríveis se o sistema falhar". Um ex-engenheiro da Boeing que pediu para permanecer anônimo diz à KOMO que o problema é especialmente preocupante, pois foi encontrado relativamente cedo no serviço do avião:
“It’s unusual to have a crack in the pickle fork. It’s not designed to crack that way at all. Period.”	"É incomum ter uma rachadura no garfo de picles. Não foi feito para quebrar dessa forma. Ponto final."
Cracks found in critical part (called a pickle fork) that keeps wing attached to 737-NG (not MAX) fuselage. One found earlier in month, now more on other planes. Found early in plane's lifespan. Boeing & FAA scrambling to find extent of problem.	Rachaduras encontradas na parte crítica (chamada de garfo de picles) que mantém a asa presa à fuselagem 737-NG (não MAX). Um encontrado no início do mês, agora mais em outros aviões. Encontrado no início da vida útil do avião. Boeing & FAA lutando para encontrar extensão do problema.
IN THE PAST TIME 2019	NO TEMPO PASSADO 2019
Hairline cracks were found in the pickle forks of Boeing’s 737 New Generation family, which includes the 737-800, in 2019.	Rachaduras [finas como] fio de cabelo foram encontradas nos garfos de picles da família 737 New Generation da Boeing, que inclui o 737-800, em 2019.
The FAA will required operators on certain Being 737 NG jetliners to conduct inspections for structural cracks. Boeing notified the agency of the matter after it discovered the cracks while conducting modifications on a heavily used aircraft. Subsequent inspections uncovered similar cracks in a small number of additional planes. The FAA have instructed operators to conduct specific inspections, make any necessary repairs and to report their findings to the agency immediately.	A FAA exigiu que os operadores de certos jatos 737 NG realizassem inspeções para rachaduras estruturais. A Boeing notificou a agência acerca do assunto depois que descobriu as rachaduras enquanto conduzia modificações em uma aeronave muito usada. Inspeções subsequentes descobriram rachaduras semelhantes em um pequeno número de aviões adicionais. A FAA instruiu os operadores a realizar inspeções específicas, fazer os reparos necessários e informar suas descobertas à agência imediatamente.
Pickle Forks Cracks	Rachaduras de Garfos de Picles
Named after the utensil used to pierce and handle pickles, pickle forks are the component that attach the plane’s body to its wing structure. These components help to “manage the stress, torque and aerodynamic forces that bend the connection between the wings and the body of the jet”.	Com o nome do utensílio usado para perfurar e manusear picles, garfos de picles são o componente que prende o corpo do avião à estrutura da asa. Esses componentes ajudam a "gerenciar o estresse, o torque e as forças aerodinâmicas que dobram a conexão entre as asas e o corpo do jato".
The planes are supposed to make up to 90,000 flights throughout their life without such structural damages. The first inspection round showed that the problem is systematic and serious:	Os aviões devem efetuar até 90.000 voos ao longo de sua vida sem tais danos estruturais. A primeira rodada de inspeção mostrou que o problema é sistemático e grave:
The results of the first week of inspections are 5% of the inspected aircraft have cracks with the lowest flight cycle aircraft with cracks at 23,600 flights.	Os resultados da primeira semana de inspeções são que 5% das aeronaves inspecionadas têm rachaduras em aeronave com menor ciclo de voo apresentadas rachaduras em [ciclo] com 23.600 voos.
Each plane will take three weeks to repair. But the supply of replacement parts for the cracked component is limited and it may take longer to produce new ones.	Cada avião levará três semanas para ser consertado. Mas o fornecimento de peças de reposição para o componente rachado é limitado e pode levar mais tempo para produzir novas.
It is not clear yet what causes the cracks in the forged aluminum part. Many older NG were retrofitted with winglets on the tips of their wings. These may have led to unforeseen loads or vibrations. It is possible that some of the younger 737 NG airplanes have a similar problem.	Ainda não está claro o que causa as rachaduras na parte de alumínio forjado. Muitos NG mais velhos foram adaptados com “winglets”nas pontas de suas asas. Isso pode ter levado a cargas ou vibrações imprevistas. É possível que alguns dos aviões mais jovens de 737 NG tenham um problema semelhante.

BACKGROUND

FROM: THE BOEING COMPANY

TO: Boeing Correspondence (MOM)

[MESSAGE NUMBER:MOM-MOM-19-0536-01B] Multi Operator Message

MESSAGE DATE: 30 Sep 2019 1731 US PACIFIC TIME / 01 Oct 2019

0031 GMT

This message is sent to all 737NG Customers, Regional Directors,

Regional Managers and Boeing Field Service Bases.

CATEGORY: Maintenance, Engineering, Flight Operations, Safety,

Regulatory

SERVICE REQUEST ID: 4-4593495493

ACCOUNT: Boeing Correspondence (MOM)

DUE DATE: No Action Required

PRODUCT TYPE: Airplane

PRODUCT LINE: 737

PRODUCT: 737NG

ATA: 5300-00

This message is sent to advise all 737NG operators of a Safety

Service Related Problem (SRP) which will result in an Alert

Service Bulletin 737-53A1395. This message provides 737NG

operators with inspection details, inspection methods, and an

inspection results report example, prior to the release of

Service Bulletin. The Boeing Company requests that operators

report back to The Boeing Company the inspection results, even

if there is no crack finding. The Boeing Company anticipates

that the Federal Aviation Administration (FAA) will mandate the

actions defined in this multi-operator message (MOM) through the 

Immediate Adopted Rule (IAR) process.

SUPPLEMENTARY INFORMATION: On June 2, 1999, the FAA received a report of a severe vibration incident on a Boeing Model 737-800 series airplane, which had accumulated 3,517 total flight hours and 1,284 total flight cycles. The airplane was involved in a high-speed descent with speed brakes extended while operating at an airspeed of 320 knots. During the descent, severe vibration occurred at 250 knots. At 230 knots, the speed brakes were retracted and the vibration stopped. The landing was uneventful.

Inspection of the airplane revealed that the upper flange of the right elevator tab mast fitting, to which the elevator tab push rods are attached, was found fractured. The lower flange of the fitting was not damaged. In addition, excessive freeplay in the elevator tab also was observed and measured during the inspection.

Further analysis confirmed that the damage to the fitting was aggravated by speed-brake-induced airframe vibration. Such vibration could lead to damage of the elevator tab mast fitting, excessive freeplay in the tab, and consequent separation of the tab mast fitting from the tab. Excessive freeplay in the tab could result in severe airframe vibration and consequent damage to the tab, elevator, and horizontal stabilizer. Separation of the elevator tab mast fitting will result in a free tab. These conditions, if not corrected, could result in loss of controllability of the airplane.

UPDATE FOR

China Eastern Airlines flight MU5735: 

second black box found  

March 27, 2022

 

ENGLISH	PORTUGUÊS
The plane’s data recorder could reveal details of its speed and altitude before it crashed in southern China	O gravador de dados do avião pode revelar detalhes de sua velocidade e altitude antes de cair no sul da China.
The black box was found buried under 1.5 meters of soil and will be flown to Beijing for analysis, state broadcaster CCTV reports	A “caixa preta” foi encontrada enterrada sob 1,5 metros de solo e será levada para Bejing para análise, informa a emissora [chinesa] estatal CCTV.
"Recovery workers have found the second black box of China Eastern Airlines flight MU5735 , Chinese state broadcaster CCTV reported on Sunday, potentially offering vital clues about the accident in which 132 people died. The flight data recorder was found around 9.20am buried about 1.5 meters (5 feet) under the soil at the mountainous crash site in the southern Chinese region of Guangxi, the report said. “It was cylindrical and covered in soil,” Chen Xiaohui, the deputy commander of the fire brigade in the regional capital Nanning, told CCTV.	"Os trabalhadores da recuperação encontraram a segunda “caixa preta” do voo MU5735 da China Eastern Airlines, informou a emissora estatal chinesa CCTV neste Domingo [27/03], potencialmente oferecendo pistas vitais sobre o acidente em que 132 pessoas morreram. O gravador de dados de voo [FDR] foi encontrado por volta das 09:20 horas [Hora Local] enterrado a cerca de 1,5 metros sob o solo no local montanhoso da queda na região sul de Guangxi na China, segundo o relatório. "Era cilíndrico e coberto de barro", disse Chen Xiaohui, vice-comandante da brigada de incêndio na capital regional Nanning, à CCTV.
The device will be flown to Beijing for data analysis alongside the cockpit voice recorder, which was found on Wednesday. The flight data recorder stores important data such as the flight path, speed, altitude and engine power, which can reveal whether human error or instrument problems could have contributed to a crash. Searchers had been using metal detectors to look for the device in hilly countryside near Wuzhou city.	O dispositivo será levado para Pequim para análise de dados ao lado do gravador de voz do cockpit, que foi encontrado na Quarta-feira [23/03]. O gravador de dados de voo armazena dados importantes, como a rota de voo, velocidade, altitude e potência do motor, que podem revelar se erros humanos ou problemas de instrumentos podem ter contribuído para uma queda. Os pesquisadores estavam usando detectores de metais para procurar o dispositivo em um campo montanhoso perto da cidade de Wuzhou.

Boeing 737's Horizontal Stabilizer Must Be Scrutinized

FAA: This AD is effective May 20, 2013.

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. This AD was prompted by reports of an incorrect procedure used to apply the wear and corrosion protective surface coating to attach pins of the horizontal stabilizer rear spar. This AD requires inspecting to determine the part number of the attach pins of the horizontal stabilizer rear spar, and replacing certain attach pins with new, improved attach pins. We are issuing this AD to prevent premature failure of the attach pins, which could cause reduced structural integrity of the horizontal stabilizer to fuselage attachment, resulting in loss of control of the airplane.

 

We estimate that this AD affects 1,050 airplanes of U.S. registry.

We estimate the following costs to comply with this AD:

Estimated Costs
Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Inspection and attach pin replacement	39 work-hours × $85 per hour = $3,315	Up to $6,312	$9,627	Up to $10,108,350.

According to the manufacturer, some of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected individuals. We do not control warranty coverage for affected individuals. As a result, we have included all costs in our cost estimate.

 Applicability

(1) This AD applies to all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes, certificated in any category.

(2) Installation of Supplemental Type Certificate (STC) ST00830SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/408E012E008616A7862578880060456C?OpenDocument&Highlight=st00830se) does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST00830SE is installed, a “change in product” alternative method of compliance (AMOC) approval request is not necessary to comply with the requirements of 14 CFR 39.17. For all other AMOC requests, the operator must request approval for an AMOC in accordance with the procedures specified in paragraph (k) of this AD.

 

Unsafe Condition

This AD was prompted by reports of an incorrect procedure used to apply the wear and corrosion protective surface coating to attach pins of the horizontal stabilizer rear spar. We are issuing this AD to prevent premature failure of the attach pins, which could cause reduced structural integrity of the horizontal stabilizer to fuselage attachment, resulting in loss of control of the airplane.

Part Number (P/N) Inspection

For airplanes having line numbers 1 through 3534 inclusive: Before the accumulation of 56,000 total flight cycles, or within 3,000 flight cycles after the effective date of this AD, whichever occurs later, inspect to determine the part number of the attach pins of the horizontal stabilizer rear spar. A review of airplane maintenance records is acceptable in lieu of this inspection if the part number of the attach pin can be conclusively determined from that review.

 

Replacement

If, during the inspection required by paragraph (g) of this AD, any horizontal stabilizer rear spar attach pin has P/N 180A1612-3 or 180A1612-4, prior to the accumulation of 56,000 total flight cycles on the pin, or within 3,000 flight cycles after the effective date of this AD, whichever occurs later, replace with a new attach pin having P/N 180A1612-7 or 180A1612-8, respectively, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-55-1093, dated April 9, 2012.

 

 

 

All Older Boeings 737-300, -400, and -500 Are Under Emergency Fuselage Inspection

FAA issues airworthiness directive for Boeing Model 737-300, -400, and -500 series airplanes.

FAA emite diretriz de aeronavegabilidade para modelos de aviões Boeing séries 737-300, -400 e -500.

Vídeo mostrando a extensão da avaria  Youtube video

• Airworthiness Directive 2011-08-51 FAA Diretriz de Aeronavegbilidade

Data: 05 ABRIL 2011

Diretriz de Aeronavegabilidade

Esta emergência foi resultada de um relatório indicando que um Modelo de  Boeing série 737-300, matrícula N632SW, experimentou uma descompressão rápida quando uma junção na cobertura do teto na corda S-4L entre a estação (BS) 664 e BS 727 rachou e abriu. A investigação mostrou que a rachadura foi localizada na superfície inferior da fileira de fixadores. A aeronave tinha acumulado 39.781 ciclos totais de voo e 48.740 horas totais de voo. Esta condição, se não corrigida, poderia resultar numa descompressão descontrolada no avião. Devido à junção na cobertura e a configuração do rasgão ser o mesmo nos modelos de Boeing das séries 737-400 e -500, estas aeronaves podem estar sujeitas à condição da insegurança identificada.

The Southwest Airlines jet forced to land last week after a gash opened in its fuselage had made an average of seven flights a day over its 15 years of service - a demanding schedule for any jetliner.

O avião da Southwest Linhas Aéreas forçado a pousar na última semana após um talho aberto na sua fuselagem tinha feito uma média de sete vôos por dia durante seus 15 anos de serviço – um programa de demanda para qualquer jato de linha aérea.

Federal Aviation Administration officials disclosed Tuesday that the Boeing 737-300 had flown 48,740 hours over its lifetime and gone through 39,781 flight cycles -- takeoffs and landings that tend to place the most stress on a plane's fuselage along with changes in cabin pressures.

Agentes da FAA revelaram na Terça-feira (5) que o Boeing 737-300 tinha voado 48.740 horas durante seu tempo de serviço e atingido 39.781 ciclos de vôo – decolagens e pousos que tendem a colocar o maior estresse na fuselagem do avião acompanhado de mudanças na pressão da cabine.

Aviation experts had initially speculated that the wear and tear Southwest planes typically endure - making an average of six flights per day - contributed to the incident. Southwest is the leading low-cost carrier in an industry that is highly competitive.

Especialistas em aviação tinham inicialmente especulado que o uso e o rasgão nos aviões que Southwest tipicamente sofreram – fazendo uma média de seis vôos por dia – contribuiu para o acidente. A Southwest é a líder de empresas aéreas de baixo-custo numa indústria que é altamente competitiva.

Flight 812, bound from Phoenix to Sacramento, had 118 passengers aboard when it made a safe emergency landing in Yuma, Ariz., Friday. There were no serious injuries.

After the incident, Southwest cancelled about 630 flights and inspected its 78 Boeing 737s, finding five others with fuselage cracks. The airline resumed normal flight operations Tuesday.

O Voo 812, saiu de Phoenix para Sacramento, tinha 118 passageiros a bordo quando ele fez um pouso de emergência em Yuma, Arizona, na Sexta-Feira (1). Não houve feridos graves.

Após o acidente, a Southwest cancelou cerca de 630 voos e inspecionou seus 78 Boeings 737s, encontrando cinco outros com rachaduras na fuselagem. A empresa aérea assumiu operações normais de vôo na Terça-feira (5).

Also on Tuesday, the FAA ordered all airlines to conduct detailed inspections within five days of older model Boeing 737-300s, 400s and 500s that have logged more than 35,000 flight cycles. The directive also requires airlines to check heavily-used 737s before they reach 30,000 cycles and orders that the older planes, which are mostly owned by Southwest, be re-inspected every 500 cycles.

Também na Terça-feira (5), a FAA ordenou a todas empresas de linhas aéreas a conduzir inspeções detalhadas dentro de cinco dias nos modelos antigos de Boeing 737-300, -400 e -500 que tenham acumulado mais que 35.000 ciclos de vôos. A diretriz também exige que as empresas verifiquem os Boeings 737 com uso pesado antes que eles atinjam 30.000 ciclos e ordena que os aviões mais velhos, os quais são principalmente pertencentes à Southwest, sejam re-inspecionados a cada 500 ciclos.

Paul Richter, chief project engineer for 737s at Boeing, said during a media briefing that the fatigue cracks suspected in the Southwest rupture occurred sooner than Boeing expected in the life of the plane. The company also issued a service order instructing airlines to check their planes.

Paul Richter, engenheiro chefe de projeto dos 737s na Boeing, disse durante uma explanação à mídia que a suspeitadas rachaduras por fadiga na ruptura do avião da Southwest ocorreram mais cedo do que o esperado na vida do avião. A companhia também emitiu uma ordem de serviço instruindo empresas aéreas  verificarem seus aviões.

FAA officials estimate that about 175 planes will be affected worldwide, including 80 in the United States. Domestic airlines must comply with the directive, whereas foreign carriers often honor the orders voluntarily.

Agentes da FAA estimam que cerca de 175 aviões serão afetados mundialmente, incluindo 80 nos Estados Unidos. Empresas de Linhas Aéreas Domésticas devem sujeitar-se à diretriz, enquanto empresas estrangeiras frequentemente honram as ordens voluntariamente.

Southwest Airlines Flight 812, a Boeing 737 carrying about 118 people out of Phoenix for Sacramento, Friday, diverted to Yuma Marine Corps air station in Arizona after an in-flight fuselage rupture caused rapid decompression at 36,000 feet. Passengers who called in to local news stations said a six foot long gash opened with a loud bang in the top of the cabin. They said the sky was visible through the opening and that some passengers lost consciousness during the rapid descent to 11,000 feet. According to Southwest, a flight attendant was the only one aboard to have suffered an injury. One passenger who saw the flight attendant speculated that the crewmember may have broken his nose. The NTSB has sent a Go Team to investigate the fuselage rupture.

Southwest Airlines Voo 812, um Boeing 737 carregando cerca de 118 pessoas de Phoenix para Sacramento, na Sexta-feira (1) alternou para estação aérea Yuma Marine Corps, no Arizona após uma ruptura da fuselagem em voo causando descompressão rápida a 36.000 pés. Passageiros que foram entrevistados por telefone pelas emissoras de notícia disseram que um talho abriu com 1,80 m com um estrondo antes no topo da cabine. Eles disseram que o céu estava visível através da abertura e que alguns passageiros perderam a consciência durante a descida rápida para 11.000 pés. De acordo com a Southwest, uma comissária de voo foi a única a bordo a sofrer ferimento. Um passageiro que viu a comissária de voo, especulou que a comissária pode ter quebrado seu nariz.