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Safety Recommendation Details

Safety Recommendation A-17-002
Details
Synopsis: On June 7, 2013, about 0925 coordinated universal time, an EMB-145LR, registration B-3052, operating as China Eastern Airlines flight MU2947, departed the left side of runway 18L onto taxiway A2 while landing at Hongqiao International Airport, Shanghai, China, in moderate rain. The flight originated from Huai’an Lianshui Airport, Jiangsu, China. The 25 crewmembers and 44 passengers were uninjured, and the nose landing gear sustained minor damage.2 After this incident, the nosewheel steering manifold assembly and electrohydraulic servo valve (EHSV) were tested by the components’ manufacturers (Parker Aerospace and Woodward HRT, respectively) according to their returned component acceptance test protocols, which are the same tests that newly manufactured components would undergo before delivery.
Recommendation: TO EMBRAER (EMPRESSA BRASILEIRA DE AERONAUTICA, S.A.): In cooperation with Parker Aerospace and Woodward HRT, study and revise the acceptance test procedures for the nosewheel steering manifold assembly and electrohydraulic servo valve on Embraer EMB-135, EMB-140, and EMB-145 aircraft to adequately identify any foreign object debris that may be present.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Alternate Action
Mode: Aviation
Location: Shanghai, China
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA13WA123
Accident Reports:
Report #: ASR-17-02
Accident Date: 6/7/2013
Issue Date: 2/2/2017
Date Closed: 8/31/2017
Addressee(s) and Addressee Status: Embraer (Empressa Brasileira de Aeronautica, S.A.) (Closed - Acceptable Alternate Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: Embraer (Empressa Brasileira de Aeronautica, S.A.)
Date: 8/31/2017
Response: We note that Embraer and Parker Aerospace determined that detecting FOD in the EHSV depends on abnormal pressure readings, which are symptoms of the EHSV first-stage nozzles being partially or totally blocked. As a result, detection depends on the size and position of the FOD inside the valve, which may be random and may shift over time. Embraer and Parker Aerospace do not believe it is feasible to use testing to identify FOD inside the valve; therefore, they believe that efforts to prevent valve contamination should be directed toward improving production and maintenance procedures to avoid introducing FOD, rather than trying to detect FOD with an acceptance test at a later stage. In 2014, Parker and Woodward identified and implemented improvements to tools, equipment, procedures, and training aimed at strictly controlling processes where FOD may be introduced in the EHSV. Also, in March 2017, Parker audited Woodward and found that the 2014 changes to the EHSV flow-grind process that minimize the possibility of contamination were effective and complied with the quality system requirements. We agree with Embraer that the revisions in 2014, with their efficacy validated in the March 2017 audits, are an acceptable alternate response that satisfies Safety Recommendation A-17-2, which is classified CLOSED—ACCEPTABLE ALTERNATE ACTION.

From: Embraer (Empressa Brasileira de Aeronautica, S.A.)
To: NTSB
Date: 5/4/2017
Response: -From Mauro Kern, Executive Vice President, Operation and Chief Operating Officer: Embraer recognizes the value of recommendations issued by the national investigation authorities with the objective to promote continuous improvement to the safety of the aviation system worldwide. In the effort to provide the response to the recommendations A-17-2 and A-17-3, Embraer had been working in cooperation with Parker, Woodward HAT and the Brazilian authorities (CENIPA and ANAC). The result of this work was already consolidated in terms of describing the actions considered as adequate to address the issues listed in the report ASR-17-02. Recently however, Embraer was informed by CENIPA that they, as the Brazilian Investigation Authority, would like to send the detailed response to the recommendations A-17-2 and A-17-3 directly to NTSB. We have already provided our proposal and a formal response from the CENIPA to the NTSB is expected soon. Embraer reaffirms its commitment to advise CENIPA's accredited representatives and, in this way, continuously provide assistance to the investigations conducted by the NTSB.

From: Embraer (Empressa Brasileira de Aeronautica, S.A.)
To: NTSB
Date: 5/3/2017
Response: -From Major General Fredico Alberto Marcondes Felipe, Chief of CENIPA and Roberto Fernandex Alves, Colonel: This letter is from the Ministry of Defense, Command of Aeronautics, Aeronautical Accident Investigation and Prevention Center (CENIPA) of Brazil: Embraer answer to NTSB Safety Recommendation A-17-2: • Embraer and Parker have reviewed the NTSB Safety Recommendation A-17-2 and the production and maintenance procedures for the EHSV and understand that there are 2 approaches to prevent contamination of the EHSV by FO (foreign objects): 1.. To introduce additional steps after complete assembly to detect FO inside the valves; 2. To improve valves production and maintenance process in order to avoid contamination by FO. • Experience gathered during those investigations shows that the ability to detect such contaminants depend on abnormal pressure readings, which are symptoms of partial or total blockage of the EHSV first stage nozzles. In other words, the detection depends on the foreign object size and position inside the valve, which may be random and shift over time. • Based on the expressed above, Embraer and Parker consider that it is not feasible to identify foreign objects inside the valve by means of testing and that efforts to prevent valve contamination should be directed to the improvement of production and maintenance procedures in order to avoid FO introduction, rather than attempt to promote its detection at a later stage. • To this end, in 2014, Parker and Woodward identified and implemented improvements to tools, equipment, procedures and training of personnel, aimed first and foremost at the strict control of processes where there is the potential of causing FO to be introduced in the electro-hydraulic servo valve. • Also, on March 2017, Parker audited Woodward and found that the changes implemented to the EHSV flow-grind process to minimize the possibility of contamination back in 2014 were effective and its quality system met requirements put forth by the AS9 l 00 Rev C.

From: NTSB
To: Embraer (Empressa Brasileira de Aeronautica, S.A.)
Date: 2/1/2017
Response: On January 26, 2017, we adopted our safety recommendation report concerning uncommanded nosewheel steering anomalies during landing in Embraer EMB-145 regional jets. Additional information may be found in the safety recommendation report, which can be accessed at our website (www.ntsb.gov) under report number ASR-17-02. As a result, we issued five new recommendations, including three to the Federal Aviation Administration and the following two recommendations to Embraer.