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.