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Safety Recommendation Details

Safety Recommendation A-16-006
Details
Synopsis: On March 11, 2016, the National Transportation Safety Board (NTSB) adopted our safety recommendation report concerning a June 5, 2015, incident in which United Express flight 4776, a Bombardier DHC-8-202 airplane, experienced an in-flight fire at the right windshield terminal block while on approach to Bradley International Airport, Windsor Locks, Connecticut.
Recommendation: TO BOMBARDIER, INC.: Revise the Bombardier DHC-8 windshield inspection intervals to provide more frequent inspections in accordance with the windshield manufacturer’s recommendations.
Original recommendation transmittal letter: PDF
Overall Status: Open - Acceptable Response
Mode: Aviation
Location: Windsor Locks, CT, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: ENG15IA024
Accident Reports: Safety Recommendation Report: Preventing Windshield Arcing, Smoke, and Fire on Bombardier DHC-8 Airplanes
Report #: ASR-16-001
Accident Date: 6/5/2015
Issue Date: 4/12/2016
Date Closed:
Addressee(s) and Addressee Status: Bombardier, Inc. (Open - Acceptable Response)
Keyword(s):

Safety Recommendation History
From: NTSB
To: Bombardier, Inc.
Date: 7/17/2018
Response: We note that you are currently reevaluating the 8,000-hour or 5-year inspection interval period, and that your maintenance engineering department plans to present new system tasks and inspection intervals at its next meeting with operators and Transport Canada–Civil Aviation, the certifying authority for the state of design and manufacture for the Bombardier DHC 8. These revisions will include a general visual inspection of the moisture seal and the addition of damage limits, with an inspection interval of every 1,600 hours or 12 months. Pending completion of these revisions to the windshield inspection intervals, Safety Recommendation A-16-6 is classified OPEN--ACCEPTABLE RESPONSE.

From: Bombardier, Inc.
To: NTSB
Date: 6/12/2018
Response: -From David Fisher, Director, Bombardier Commercial Aircraft, ASIO (Air Safety Investigation Office): A-16-6 “Revise the Bombardier DHC-8 windshield inspection intervals to provide more frequent inspections in accordance with the windshield manufacturer’s recommendations. You reported that the Maintenance Review Board tasks have been revised to provide more frequent inspection intervals. We are concerned, however, because the inspection interval specified for the terminal blocks has not changed, with the exception of a one-time re-torqueing of the terminal blocks at 8,000 hours or 5 years, as specified in airworthiness directive (AD) CF-2017-25. We note that the AD also requires a one-time inspection of the moisture seal at 1,600 hours or 12 months; yet, the windshield manufacturer (PPG Aerospace Transparencies) recommends inspecting the moisture seal around the periphery of the windshield every 4 months or 1,000 flight hours. Although we are aware that you are currently revising the maintenance task cards for the terminal blocks to include the same inspection interval that is specified in the AD (8,000 hours or 5 years), we believe this is still too infrequent to adequately address signs of deterioration and conditions that could lead to arcing, smoke, fire, or overheating. We are aware that after this incident, CommutAir voluntarily changed its inspection intervals on the terminal blocks to 1,000 to 1,200 hours; however, we remained concerned about the disparity between Bombardier’s instructions for inspecting DHC-8 windshield components and its recommended maintenance intervals and the detailed instructions and maintenance intervals recommended by the windshield manufacturer. Pending revisions to the windshield inspection intervals that are consistent with the windshield manufacturer’s recommendations, Safety Recommendation A-16-6 is classified “Open—Unacceptable Response.” Bombardier Response: The inspection period of 8,000 hours or 5 years was based upon the inspection periods used in the EWIS program and therefore aligned with other Electrical component inspections. Bombardier is re-evaluating this time interval inspection period, Maintenance Engineering will present new system tasks and inspection intervals at the next meeting with Operators and TCCA to perform a GVI of the moisture seal and to add damage limits. The time interval recommendation to inspect the Windshield every 1600 hours or every 12 months was decided by the Bombardier Corrective Action Review Board process (CARB), which evaluated the in-service history of previous windshield events and determined that this time interval was appropriate to ensure windshield integrity was maintained.

From: NTSB
To: Bombardier, Inc.
Date: 4/20/2018
Response: You reported that the Maintenance Review Board tasks have been revised to provide more frequent inspection intervals. We are concerned, however, because the inspection interval specified for the terminal blocks has not changed, with the exception of a one-time retorqueing of the terminal blocks at 8,000 hours or 5 years, as specified in airworthiness directive (AD) CF 2017 25. We note that the AD also requires a one-time inspection of the moisture seal at 1,600 hours or 12 months; yet, the windshield manufacturer (PPG Aerospace Transparencies) recommends inspecting the moisture seal around the periphery of the windshield every 4 months or 1,000 flight hours. Although we are aware that you are currently revising the maintenance task cards for the terminal blocks to include the same inspection interval that is specified in the AD (8,000 hours or 5 years), we believe this is still too infrequent to adequately address signs of deterioration and conditions that could lead to arcing, smoke, fire, or overheating. We are aware that after this incident, CommutAir voluntarily changed its inspection intervals on the terminal blocks to 1,000 to 1,200 hours; however, we remained concerned about the disparity between Bombardier’s instructions for inspecting DHC-8 windshield components and its recommended maintenance intervals and the detailed instructions and maintenance intervals recommended by the windshield manufacturer. Pending revisions to the windshield inspection intervals that are consistent with the windshield manufacturer’s recommendations, Safety Recommendation A-16-6 is classified OPEN--UNACCEPTABLE RESPONSE.

From: Bombardier, Inc.
To: NTSB
Date: 12/14/2017
Response: -From David Fisher, Manager, Air Safety Investigations Office (ASIO): BA Safety Action Taken: MRB tasks have been revised to provide more frequent inspection intervals. TC Airworthiness Directive, CF-2017-25, references the corrective action. (AD attached)

From: NTSB
To: Bombardier, Inc.
Date: 10/4/2017
Response: We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others. We normally expect actions to address our recommendations to be completed within 3 to 5 years, and we have yet to hear from you regarding your progress toward addressing these recommendations. We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, they will retain their current classification of OPEN—AWAIT RESPONSE. For additional background information about these safety recommendations, please refer to Safety Recommendation Report 16-01, Preventing Windshield Arcing, Smoke, and Fire on Bombardier DHC-8 Airplanes. Please update us at correspondence@ntsb.gov regarding your actions to address Safety Recommendations A-16-3 through -8, and do not submit both an electronic and a hard copy of the same response.